Yet Another Cycling Forum

General Category => The Knowledge => OT Knowledge => Topic started by: andygates on 22 January, 2011, 01:46:15 pm

Title: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 01:46:15 pm
This is a muttering-and-sums-out-loud thread.  I really want to display my Rugged Individualist stripes by not begging a power supply from pubs and campsites, yet I am, alas, gadget boy.

Kit to charge: phone (1540 mAh, micro USB), camera and GPS (2x AA each, will run on mini USB but won't charge), head torch (3xAA).  I can't imagine my LED tail light running out, so let's ignore the awkward AAAs that it uses. 

The nice folks at Power Monkey do a Powerchimp AA charger/gadget-feeder, which one could stack with their solar panel (reasonably robust, folding) to do most of that job in one go.  £45 or thereabouts, piecemeal from their site.

Adafruit Industries do geek kits.  The MintyBoost is effectively a Powerchimp, and there's a nice how-to for hooking up a beefy 2W (!) robust panel to the lot.  You'd need to change the lipoly charger for a NIMH charger, and waterproof your unit yourself (I think a Mentos Gum tube will do nicely, to be explored).  HOW TO – Make a solar MintyBoost, a solar power charger for your gadgets! «  adafruit industries blog (http://www.adafruit.com/blog/2010/07/09/how-to-make-a-solar-mintyboost-a-solar-power-charger-for-your-gadgets/) for the how-to; the MintyBoost pages start here http://www.adafruit.com/index.php?main_page=product_info&cPath=10&products_id=14 .  Super solder fun!

...and there's the slim but non-zero possibility that an Energizer Energi pack will take on charge if one reverses the polarity (of the neutron flow, Captain!).  Probably dioded out.  To test.

Does any other manufacturer do an AA-carrying unit?  Freeloader and Solio have integral lipoly cells; so do the new (and very well priced!) Maplin ones. 

Aha! A Freeloader add-on Freeloader AA/AAA Battery Charger (http://www.thesolarcentre.co.uk/products/Freeloader_AA_AAA_Battery_Charger-114-5.html) ... but the Freeloader's construction shouts "break me! drop my bits in the road!" to me.

Looks like generic USB AA/AAA chargers work fine with the Solio et al USB AA/AAA battery charger by Targus model TG-CHUSB (http://www.modernoutpost.com/gear/details/tg_usb_charger.php)

...or go hardcore homebrew: Solar Battery Charger With LM317T - Solar (http://www.reuk.co.uk/Solar-Battery-Charger-With-LM317T.htm)
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 01:53:15 pm
Discussion of exactly this View topic - Green or SpearmintyBoost? • adafruit industries • Customer Support Forums, DIY Electronics, Open Source Hardware, Arduino (http://forums.adafruit.com/viewtopic.php?t=5621&highlight=solar+charge)
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 02:52:18 pm
As you probably know, I'm going down the hardcore homebrew route with a view to integrating everything into one box.  I've got a working prototype (https://yacf.co.uk/forum/index.php?topic=1241.msg596232#msg596232) of the insanely efficient active rectifier (https://yacf.co.uk/forum/index.php?topic=1241.msg535693#msg535693) - no voltage drop *squee* - (for extracting useful power from a hub dynamo at the sort of pace I could expect to manage fully loaded back when I spent more time breathing solder fumes than riding bikes) and USB charging sections.  I've used this successfully to keep my ageing smartphone in power on various trips this summer.

The next stage is to add some logic to deal with excess voltage from the dynamo at speed (it's currently dissipating excess power as heat, which is wasteful and tends to toast the zener diodes on fast descents) and a battery pack.  While my Nokia is happy with an intermittent charging source, other gadgets seem not to be, and it makes things more flexible to be able to store a couple of phones worth of charge.

Adding solar and mains/12V inputs should then be straightforward.  I think I do want a solar panel for days that involve more camping than cycling, but I've yet to work out what to use.  Depends on whether I'm aiming at small devices, or running a netbook (which I reckon is just about doable, assuming it's mostly going to be used for short GPS and photo wrangling sessions, rather than prolonged spodding).  There are some utterly droolworthy flexible 5W panels (http://www.flexsolarcells.co.uk/index_files/Rollable_Series/pages/Individual_Rollable_R15_300.php) out there.

I was considering using AA NiMH cells as the battery pack, with a view to being able to charge the ones from my GPS/torch/etc.  But it seems that building the sort of multi-channel NiMH charger that entails is going to mean a lot of inductors and stuff that add weight and complexity.  It seems better to have a large lithium-ion/lithium-polymer battery pack with a single charging channel, and deal with AA/AAAs externally with an off-the-shelf charger.

I discovered the SCH600F (http://www.microbatt.co.uk/product_info.php?cPath=34&products_id=55) charger, which meets the fairly restrictive requirements of running from a 5V supply at dynamo/solar-friendly currents while having independent charging channels for the cells - nearly all USB-powered chargers charge cells in pairs for simplicity, which is useless when you've got devices that run from 3 AAAs.  It's cheap and plastic, but is surprisingly lightweight and does what it says on the tin.  It needs minor fettling to make it touring-ready, in the form of disconnecting the 'refresh' button internally, as that's just going to get knocked and waste all your valuable charge, and the addition of a Mk 1 elastic band to hold the battery compartment flap shut.
Title: Re: Solar gadgets + AA's
Post by: mattc on 22 January, 2011, 03:40:18 pm
This is a muttering-and-sums-out-loud thread.  I really want to display my Rugged Individualist stripes by not begging a power supply from pubs and campsites, yet I am, alas, gadget boy.

Can't you just use the lighter socket?
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 06:16:06 pm
That's a dirty trick in that rectifier.  Did you invent that?
Title: Re: Solar gadgets + AA's
Post by: rogerzilla on 22 January, 2011, 06:21:04 pm
What about a folding wind turbine as another option?  Wind often works on days when solar doesn't, although you get plenty of days when neither are any good.
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 06:30:44 pm
I think Kim and I are thinking along the same lines, with a "universal battery and gubbins" that will take a variety of inputs and give a variety of outputs, all at the same time.

The main difference is that I'm thinking the gubbins should be AA batteries, and Kim's going for more storage with a mighty lipoly so as to run bigger kit.  Also, she's hardcore, I'm a shopper. ;)

So, yeah, any old bit of chargey kit, so long as it was within spec, would do nicely.  Riding to camp and pitching a windmill might draw some eyebrows.  Hmm, folding fabric windmill?  Savonius or VAWT blades..? 
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 06:37:01 pm
That's a dirty trick in that rectifier.  Did you invent that?

God no!  It's a fairly standard technique for avoiding prohibitively silly diode losses where Rich Chunky Amps are involved, and crops up occasionally when efficiency is more important than cost or complexity.  I saw a post on CandlePowerForums or somwhere in which someone dismissed the associated control electronics as being too involved to be practical on a bicycle.  Fair enough if you're building a light, but I reckoned it was worth a go for a gadget that's going to live in a pannier.

Combined with the frighteningly efficient Recom switching regulators (if you're homebrewing this sort of stuff, they beat the pants off linear regs), it'll run an eTrex at about 3mph.  What's not to like?
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 06:40:22 pm
What about a folding wind turbine as another option?

I haven't tried it, but the mad science part of my brain likes the idea of clip-on vanes to go between the spokes of your dynamo wheel.  Just invert the bike and point it in roughly the right direction.   ;D

(I'm also reasonably certain that you'd need a complete bastard of a wind to get any useful power out of such a contraption, and any cyclist can tell you that those only happen when you're trying to ride the bike.)
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 07:10:15 pm
Y'know, I made a scrappy windmill exactly like that, using alu tape to make a lot of angled, slim blades, kinda like an American water-pump windmill.  It definitely turned -- but it was a junk wheel I was playing with, so no idea on genny potential; it turned lightly, not with mighty gusto.  Blew down a week later.  :D  On-bike it won't be able to rotate to track the wind, and that's probably a showstopper.

The hardcore camper-van types will use a yacht turbine, which are routinely available (even in Maplin, though the Rutland ones are the de facto standard) and go up on a high pole for clean air.  They're usually rigged to charge a 12v deep-cycle lead-acid battery in the camper's leisure circuit.  Memo to self: next leisure circuit, don't forget the shunt! :facepalm:

I think for cycle-camping, a wind turbine is overkill: well before that comes "a good dynamo".  It comes into its own for base camp somewhere cloudy.  Still, there's no reason not to try one, or a micro hydro based on a prop in a drainpipe, or a campfire stirling engine, or anything else bonkers. 
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 07:15:48 pm
or a campfire stirling engine, or anything else bonkers. 

Now that I like.

Paging Charlotte to the red courtesy phone...   :D
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 07:26:13 pm
Thought you might.  I'll spin up the Mamod...  :demon:

A thought occurred to me about solar: to work best, it's got to be sun-tracking, and the control mechanism for that is quite fancy.  But there's flowers to copy: if the panels are arranged in a shallow bowl, then the voltage is higher in the sunward petal.  All I need is a memory-elastomer that varies stiffness across voltage, and I can plant fields of sunflowers!

/dried frog pill
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 07:30:41 pm
Not really worth it for cycle camping, thobut.  You're either there to give the panel a tweak every couple of hours, or you're on the road, in which case it's either flat across the rear rack or tucked away in a pannier.

Or you're hiding in the pub, where there's mains.
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 08:22:11 pm
I just love the idea as a bit of Make art.  One for the mothballs.  Now, if I've just got three items and I wire them in parallel with a Y-shaped cable, I think it should Just Work:

(http://farm6.static.flickr.com/5002/5378261395_6814dee9be.jpg) (http://www.flickr.com/photos/andygates/5378261395/)
Circuit sketch (http://www.flickr.com/photos/andygates/5378261395/) by andygates (http://www.flickr.com/people/andygates/), on Flickr

With sun and empty batteries and no gadget, the batteries would charge.  With the gadget, it would draw on both.  With the gadget and no sun, the diode will stop it peeing away power into the panel, while it can draw on the batteries.  (assume they're well-matched, as per MintyBoost kit)

It can't be that easy, surely? 
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 08:52:28 pm
Sort of.  That's certainly how you'd do things with lead-acid batteries and appropriately matched panel and gadgets - usually 12V stuff, which for compatibility with vehicle electrical systems has a reasonably flexible definition of 12.

It's a bit trickier when you're talking USB (which has a fairly strict voltage tolerance) and NiMHs (which don't like being float charged).  There's going to be at least some electronics between the battery pack and the USB-powered gadget to give it the nice clean 5V supply it needs, and that's only going to let the current flow one way.  If the solar panel's voltage and current spec are appropriate it can probably be connected directly across the NiMH battery (ie, behind the regulator) without cooking anything, but if there's a charge controller involved (as you'd probably need for a decently big panel), it'll need to be feeding that.

...and of course there's a voltage drop across the diode.  At USB voltage that matters, even with a Schottky diode.
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 09:30:02 pm
Sort of.  That's certainly how you'd do things with lead-acid batteries

Indeed it was.  Replace the panel with the alternator, add in a relay which closes when the engine is running, and I had just such a beast.  Lovely too, apart from the lack of a shunt which, at those power levels turns out to matter in a "boiling battery acid" kind of way. :o :facepalm:

So to do the all-three-connected trick, we're looking at going hardcore.

I can start to see the appeal of KISS - charge the storage battery, then charge the devices ad hoc.  If that's the case then there's a twenty-quid Maplin charger-n-battery in an iclone-sized box that becomes "slip me under the map trap" appealing.
Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 09:37:05 pm
So to do the all-three-connected trick, we're looking at going hardcore.

Or an integrated panel-and-battery thinger.  Not sure if they come in AAbatteries-and-USB-output flavours, though.
Title: Re: Solar gadgets + AA's
Post by: andygates on 22 January, 2011, 09:52:54 pm
They all seem to be lipo. Mmm, soap.

Ooh! Look what I found! How likely is this to be any good at all? HY Mini Wind Turbine at Firebox.com (http://www.firebox.com/product/2111/HY-Mini-Wind-Turbine) it even comes with an ARMBAND! Welcome to HYmini Online
Store - Green power is in your hand (http://www.hymini.com/eshop/index.html)

Title: Re: Solar gadgets + AA's
Post by: Kim on 22 January, 2011, 09:58:07 pm
Quote
To give you an idea of its impressive capabilities, a 20 minute charge (at 19mph wind speed) should give 30 minutes playing time on an iPod, 4 minutes talk time on a mobile, or 20 snaps on a digital camera.


..yeah, impressive.   :facepalm:
Title: Re: Solar gadgets + AA's
Post by: Cunobelin on 23 January, 2011, 10:30:27 am
I know that the ideas here are well thought out, practical and effetive, but I have found the one big flaw in the whole solar process:

The lack of sun!
Title: Re: Solar gadgets + AA's
Post by: plum on 25 January, 2011, 05:41:34 am
I took a freeloader on a summer tour in France last year. Strapped it to my handlebars, was travelling north to south so it got full exposure most of the time. That was for about 5 or 6 hours riding each day then it was out on a table or wherever for the rest of the time. Provided plenty of power to keep either my mp3 player going or to charge the batteries for my HCx but not both. Was overcast most of the time, if there had been full sunshine it would have done both for sure. Not at all fragile, I was dropping it and bouncing it around non stop for four weeks, has a few scratches but nothing to impair its operation. I took a mini AA charger and often used the usb cable that came with the freeloader to charge batteries from the campsite booking computer. I'd definitely recommend the things for small devices, but not enough to guarantee power for a bunch of devices unless you can also guarantee full sun.
Title: Re: Solar gadgets + AA's
Post by: Charlotte on 25 January, 2011, 09:21:22 am
or a campfire stirling engine, or anything else bonkers. 

Now that I like.

Paging Charlotte to the red courtesy phone...   :D

*Arrives breathless in thread*

New Solar Dish Stirling Engine - From Gyroscope.com -  (http://www.gyroscopes.co.uk/d.asp?product=SOLARSTIR)
Title: Re: Solar gadgets + AA's
Post by: andygates on 25 January, 2011, 09:35:30 am
 :thumbsup:
Title: Re: Solar gadgets + AA's
Post by: Wombat on 25 January, 2011, 12:29:00 pm
Being a model engineering type, I've been aware of these things for some years, but the project has never got anywhere near the front of the build queue!  (Its behind several articulated railway engines and a fart powered gas engine).

I have seen a site with info on a massive one in the USA, it was humungous, and brought on a serious case of technofrenzy on my part, dribbling and drooling....

Here is a much smaller one... SES :: Technology (http://www.stirlingenergy.com/technology.htm)
Title: Re: Solar gadgets + AA's
Post by: mrcharly-YHT on 25 January, 2011, 01:42:20 pm
I know that the ideas here are well thought out, practical and effetive, but I have found the one big flaw in the whole solar process:

The lack of sun!
I lived on a boat for 18months with no source of power apart from a solar panel.

I can assure you that decent 3-junction panels generate power even on cloudy days. Just sod all power compared to sunny days (when the battery would be fully charged and the controller dumping spare power through the heatsink).
Title: Re: Solar gadgets + AA's
Post by: andygates on 25 January, 2011, 02:37:49 pm
Quote from: The nice lady at Power Monkey
You cannot charge a device from the Monkey or the Chimp while it is charging from a solar panel.

You can however charge a device from the panel direct with the smart phones you may need the solar nut to keep the power flow at an even 5v rate.

So there you go.  The lipoly battery stage is needed in everything and there's no sneakin' around it.  (Obviously you'd use a USB AA/AAA charger to slurp the Nut dry for other toys)
Title: Re: Solar gadgets + AA's
Post by: Kim on 25 January, 2011, 02:42:28 pm
Quote from: The nice lady at Power Monkey
you may need the solar nut to keep the power flow at an even 5v rate.

Go directly to year 8 physics.  Do not pass 'Go'.  Do not collect 200 Joules per coulomb...


It's Stephen Fry all over again!
Title: Re: Solar gadgets + AA's
Post by: mrcharly-YHT on 25 January, 2011, 03:02:15 pm
Quote from: The nice lady at Power Monkey
you may need the solar nut to keep the power flow at an even 5v rate.

Go directly to year 8 physics.  Do not pass 'Go'.  Do not collect 200 Joules per coulomb...


It's Stephen Fry all over again!
:facepalm:

One of my children was talking about electricity and units. Her teacher had described using a circuit with a '50 joule' lightbulb.
I suggested that daughter might have missheard, but she was adamant.
Title: Re: Solar gadgets + AA's
Post by: andygates on 25 January, 2011, 03:12:20 pm
Well, yes.  But for most punters, "...to keep the doofer at the right dooferage for your thingummy" would have conveyed just as much.   ;)
Title: Re: Solar gadgets + AA's
Post by: andygates on 27 January, 2011, 08:07:34 am
So, after a second look over the Powermonkey stuff, it's safe to class my device as a "heavy drain" type (iphone 4 and the like; at least it'll apply while running GPS and internets), so they're saying use a powermonkey eXplorer (stupid names argh) -- the bigger smarter battery plus a panel.  That'll run-through and may even grobble enough charge to tickle some AAs.

It's also expensive enough to go homebrew!
Title: Re: Solar gadgets + AA's
Post by: The Mechanic on 27 January, 2011, 02:13:10 pm
Don't you people have homes to go to?
Title: Re: Solar gadgets + AA's
Post by: andygates on 25 March, 2011, 07:56:49 pm
Right.  Spoke to a chap who tours around the Caledonian Wastes and he really rates his Powermonkey Explorer, but the spec sheet (https://powertraveller.com/_code/download.php?f=Powermonkey_eXplorer.pdf) has a 2200 mAh battery in the guts.  That's weaksauce (my Vapex AA's are 2900 mAh each, so that'd give a meh charge to a set of these bad boys, even though it would probably fill the phone at 1450 mAh). 

So, homebrew.  It's payday, after all. 

Ada has this solar panel, which is a beast: http://www.adafruit.com/index.php?main_page=product_info&cPath=44&products_id=200  -- 6v 300mA, and also fits nicely in any handlebar bag maptrap.  It roundly spanks the PowerMonkey solar, which is best of the readymade class.

All I need is an AA/AAA charger which will mate up to it.  I wonder if an ordinary USB charger would take those volts?
Title: Re: Solar gadgets + AA's
Post by: Kim on 25 March, 2011, 08:05:26 pm
Bung it through a low-dropout 5V regulator and you're in business.  Sort of.  The charger will probably be expecting to be able to pull at least 500mA (as per USB spec) and might refuse to charge when the voltage falls off.  Plus you've got to de-rate the panel to allow for Typical British Weather (that's the real gotcha).

Have a google around for solar charging circuits, though.  This isn't the first time someone's tried to do this.  At that sort of current you can probably get away with putting the panel straight across a couple of cells in series (with blocking diode so it doesn't discharge in the dark).  The tricky bit there is knowing when to stop - when the battery is charged it'll start to cook.

Title: Re: Solar gadgets + AA's
Post by: andygates on 25 March, 2011, 08:26:30 pm
It's the cookery that makes me sad. 

Ooh, Voltaic have done the hard work for anyone with a pile of cash: Fuse is two of their big panels and a battery, all rigged up for bikes.  Voltaic Fuse Solar Charger (http://www.voltaicsystems.com/fuse.shtml)
Title: Re: Solar gadgets + AA's
Post by: Kim on 26 March, 2011, 12:14:05 am
Now that, I like.

First thing I've seen that's remotely near my back-of-the-envelope calculations for what constitutes a reasonable amount of power and storage.

I'm still lusting after Powerfilm marine-grade flexible panels in the 5W range.  Reckon that ought to be about as good as[1] a dynamo, but without the pedalling.  And the sheer over-engineering of the things totally does it for me.


[1] On the assumption of bright sunshine being about as common as riding fast while touring, so you're going to get a couple of Watts on average.
Title: Re: Solar gadgets + AA's
Post by: andygates on 30 March, 2011, 10:50:38 pm
I'm still lusting after phased plasma rifles in the 40W range.

ftfy  8)

I have foolishly added the word "circuit" to my googles and my god it's full of nerds.  :thumbsup:

And content farms.   :sick:

So... it'd be fairly simple to rig a 5v regulator for a 6v panel with an LM2941 or its low-dropout ilk.  That makes a "USB-erizer" a matchbox dongle, easy to connect a USB charger too as long as it was useful at low voltages.  Hm.  Isn't there anything that just scrapes dribs and drabs of electrickery and pumps them in regardless?  Or am I confusing electrons and water again?

Edit to add (after sucking on Ada's fount of boffinage): 'course, I could put a boost converter in first, then regulate what came out -- you'd lose efficiency in good light but gain it in low light.  A boost around 2.5 - 3x would let you use a cheapo regulator and get use out of those gloamy hours.

Or maybe I'll just stick one of these on a backpack, sashimono style:
   50W Telescopic Vertical Axis Wind Turbine Free Delivery : Wind Power : Maplin
 (http://www.maplin.co.uk/50w-telescopic-vertical-axis-wind-turbine-396269?c=41578) 8)
Title: Re: Solar gadgets + AA's
Post by: Kim on 31 March, 2011, 12:56:27 am
I'm still lusting after phased plasma rifles in the 40W range.

ftfy  8)

Well obviously, but not solar powered ones.  That would be ...disappointing.


Quote
So... it'd be fairly simple to rig a 5v regulator for a 6v panel with an LM2941 or its low-dropout ilk.  That makes a "USB-erizer" a matchbox dongle, easy to connect a USB charger too as long as it was useful at low voltages.  

 :thumbsup:


Quote
Hm.  Isn't there anything that just scrapes dribs and drabs of electrickery and pumps them in regardless?  Or am I confusing electrons and water again?

That'd be charging up an internal battery pack (or supercap or something) and then powering the USB gadget off the stored charge.  While you can scrape dribs and drabs into a known battery by various means, it's not as simple when you're trying to feed something that's expecting a regulated voltage source with defined current limits.


Actually, I quite like water analogies for electricity...  Voltage is height; current is flow; resistance is diameter of pipe; power is flow x change in height along a length of pipe; energy is amount of water x how high up your bucket is.  You can even do transistors as flap-operated sluice gates.  It all gets a bit Escher if you try to combine multiple transistors to make digital logic circuits, though.


Quote
Edit to add (after sucking on Ada's fount of boffinage): 'course, I could put a boost converter in first, then regulate what came out -- you'd lose efficiency in good light but gain it in low light.  A boost around 2.5 - 3x would let you use a cheapo regulator and get use out of those gloamy hours.

So you add a voltage-controlled switch (relay, FET, whatever - preferably something that doesn't need too much current) to bypass the boost converter when the panel output's above the 6.5V or whatever minimum the regulator needs.  Best of both worlds.
Title: Re: Solar gadgets + AA's
Post by: andygates on 31 March, 2011, 09:59:49 am
Well obviously, but not solar powered ones.  That would be ...disappointing.
You get one shot, then rack it on a ziggurat-topped altar in the mountain sun to charge for generations.  It's probably why the Mayan calendar has such long cycles.
Quote
So you add a voltage-controlled switch (relay, FET, whatever - preferably something that doesn't need too much current) to bypass the boost converter when the panel output's above the 6.5V or whatever minimum the regulator needs.  Best of both worlds.
And you'd end up with a reliable 5v with highly variable current across a wide range of lighting conditions.  We know that a phone won't charge from that, but what about a bogstandard USB battery charger like the doughty Eneloop?

What we need is a bench and a variable power supply and probes.  Or moar googles.   :thumbsup:
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 31 March, 2011, 11:12:40 am
whilst you boffins discuss mountain top altars and the amount of sun /moonshine thereon ...

what's the collected wisdom of the forum on charging AAs from a 6V 3W dynohub? 
Evidently one needs to convert AC to DC with something like an E-Werk or a Pedalpower+ Universal cable  - or is there something lower cost?   and  any suitable chargers to run directly off it without running through a Li-poly ?

I don't mind plugging stuff together but soldering voltage regulators and diodes & stuff is beyond me, except with absolutely crystal clear step-by-step illustrated instructions .
Title: Re: Solar gadgets + AA's
Post by: Kim on 31 March, 2011, 01:24:29 pm
what's the collected wisdom of the forum on charging AAs from a 6V 3W dynohub?

B&M Ixon IQ + ride & charge cable.  You get a pretty good bike light thrown in.

One of the multitude of dynamo-USB supplies combined with a ubiquitous USB powered battery charger.

Connecting the batteries (in series, which is only sensible if they're all at the same level of charge) directly to the dynamo via a bridge rectifier - works surprisingly well, as the dynamo supply is effectively a constant-current source, and 500mA is a reasonably AA/AAA-friendly charging rate.  The gotcha is that there's no charge monitoring, so once they're full they'll start to get hot, which isn't good for the long-term health of the batteries.
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 31 March, 2011, 03:03:53 pm
what's the collected wisdom of the forum on charging AAs from a 6V 3W dynohub?

One of the multitude of dynamo-USB supplies combined with a ubiquitous USB powered battery charger.



I'm a newbie at all of this... and on a budget.  Can you point us in the right directions amongst these ubiquitous multitudes ?
I conversed with the folks at Pedalpower about this and they were talking about taking 11 hours to charge 2 x 1000mAh AAA unless using one of they Li-Poly batteries, which adds a level of complexity and cost I am keen to avoid.
Title: Re: Solar gadgets + AA's
Post by: andygates on 31 March, 2011, 03:16:19 pm
...and therein lies the "just buy some Duracells from the garage" rub, methinks.
Title: Re: Solar gadgets + AA's
Post by: Kim on 31 March, 2011, 03:22:47 pm
I'm a newbie at all of this... and on a budget.  Can you point us in the right directions amongst these ubiquitous multitudes ?

Something like the Dahon Reecharge (http://www.thinkbiologic.com/products/reecharge-power-pack) or B&M E-Werk (http://www.bumm.de/produkte/e-werk/e-werk.html).  On a budget they aren't, though.  There are designs for homebrew equivalents on the web, of varying levels of cleverness (read: efficiency), which will work out a lot cheaper, but require a bit of electronics-fu.

USB battery chargers are much easier to come by.  You can probably find them in your local supermarket.  The problem with those is that they tend to be limited to charging a pair of cells in series at fairly conservative rates.

One of the better options I've found is the SCH600F (http://www.microbatt.co.uk/product_info.php?products_id=55) charger.  It has 4 independent charging channels, and will run on USB-spec power.  It's a bit cheap and plasticy, and there's a big 'refresh' button that will need to be molly-guarded or disconnected internally to avoid accidental discharge, but it appears to work.


Quote
I conversed with the folks at Pedalpower about this and they were talking about taking 11 hours to charge 2 x 1000mAh AAA unless using one of they Li-Poly batteries, which adds a level of complexity and cost I am keen to avoid.

That seems awfully conservative, or awfully inefficient.  I'm not sure which.


The problem is, there aren't any really nice solutions to this, and the commercial products are inherently niche and therefore expensive.  That's a large part of the reason I'm designing my own: it'll still be hideously expensive, but at least it'll do what I want it to do.
Title: Re: Solar gadgets + AA's
Post by: Kim on 31 March, 2011, 03:29:04 pm
...and therein lies the "just buy some Duracells from the garage" rub, methinks.

Quite.  If it's literally just standard AA/AAAs you're worried about, rather than smartphones or Garmin Edges or netbooks or similar, then you really have to be very off the grid before carrying a few sets of spares isn't by far the simplest solution.

If you're set up to charge USB-powered gadgets, then carrying a charger to do AAs as well isn't unreasonable, but otherwise I think your best low-budget options are a dumb rectifier circuit and a Mk1 finger to detect when the charge is complete (and live with the shortened life expectancy for the NiMHs) or buying/carrying spares.   :-\
Title: Re: Solar gadgets + AA's
Post by: andygates on 31 March, 2011, 04:35:31 pm
What I'm keen to have is the option of going off-grid for a while, very specifically for this LEJOG but also for non-bike stuff like kayak camping (romantic notions of Forrest Gump "just keep pedallin'" notwithstanding). 

Charlotte's just hooked me up with her magic charger, which covers all the battery angst. 

I'm pretty much sold on Ada's tough 2w panel.

And I think this might be the solar-to-USB boost-and-rectifier in one that I'm after: Single-Stage 5V USB Voltage Regulator (http://www.intersil.com/data/an/an1317.pdf).  See also here (http://electronicdesign.com/article/power/simple-buck-boost-converter-shines-in-usb-applicat.aspx) and a nice clear circuit here (http://archive.electronicdesign.com/files/29/7657/figure_01.gif). 
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 31 March, 2011, 05:28:59 pm
...and therein lies the "just buy some Duracells from the garage" rub, methinks.

Quite.  If it's literally just standard AA/AAAs you're worried about, rather than smartphones or Garmin Edges or netbooks or similar, then you really have to be very off the grid before carrying a few sets of spares isn't by far the simplest solution.


Thing is I could get through an awful lot of AAs.    There's 2 in the Garmin, 3 in the head torch - all of which need to be replaced probably once in every 24 hours, and another 4 in the Hope Vision 1 (which would become my back-up light when I get a dyno powered front light) - possibly replaced twice in 24 hours.    Say a pack of 12 every 24 hours.   On a 600 that's either a lot of weight or a lot of cost buying duracells at garage prices, when I could be using the dyno to be charging spares sequentially during daylight hours.... not to mention the environmental impact, cos I'm probably not going hunting for a recycling facility when I'm in the middle of an audax.

At the moment phone charging is not an issue because I've an old fashioned non-smart phone with a battery that can go nearly a week.....  

Sorry to be a pest, but can you point me towards a suitable site for "Building Dumb Rectifiers for Dummies" ?   I literally have no clue what to look for.
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 31 March, 2011, 06:47:04 pm
does this make sense for example....

http://i143.photobucket.com/albums/r154/n4zou/lights/DynamoUSB-2.jpg

My reading suggests the designer was using the impedance of the batteries to regulate the current to the USB rather than as a battery charger per se..., but battery charging a side benefit....  If I arranged the 4 NiMH in a battery case that's compatible with the Hope - maybe the one with PP3 connectors ?   


or this
DIY hub dynamo usb charger »  arenddeboer.com (http://www.arenddeboer.com/diy-hub-dynamo-usb-charger/)
and plug the SCH600F charger into it ?

Title: Re: Solar gadgets + AA's
Post by: andrew_s on 31 March, 2011, 07:11:02 pm
...and therein lies the "just buy some Duracells from the garage" rub, methinks.
The trouble with Duracells from the garage is that they often perform poorly in modern equipment. They don't like to give a high current, and the voltage drops below that of 1.2V rechargeables before they are half used, provoking "batteries low" turn-offs.
If you want disposables, lithium are best, but they aren't so common (supermarkets are usually the best place)  and are fairly expensive. They are very light though.
Title: Re: Solar gadgets + AA's
Post by: Kim on 31 March, 2011, 08:21:26 pm
does this make sense for example....

http://i143.photobucket.com/albums/r154/n4zou/lights/DynamoUSB-2.jpg

My reading suggests the designer was using the impedance of the batteries to regulate the current to the USB rather than as a battery charger per se..., but battery charging a side benefit....  If I arranged the 4 NiMH in a battery case that's compatible with the Hope - maybe the one with PP3 connectors ?

Ach, I wouldn't plug my shiny smartphone into that.  That 6V nominal battery voltage is way outside USB spec.

As a circuit for charging batteries it'll work fine though.  They'll just start to cook (but relatively slowly, as it's not all that much power) when they're full.



Quote
or this
DIY hub dynamo usb charger »  arenddeboer.com (http://www.arenddeboer.com/diy-hub-dynamo-usb-charger/)
and plug the SCH600F charger into it ?

Danger, lack of over-voltage protection!  That'll work, but Magic Smoke is liable to escape when going Very Fast without much of an electrical load.  The dynamo will easily exceed the 26V maximum rating of the LM2940 under those conditions.

The simple solution is to add a pair of zener diodes, of say 20V rating, back-to-back across the dynamo input.  Then the rectifier will never see more than 20V and the excess power will be dissipated as heat in the zeners.  The problem then becomes one of getting rid of the heat - I've found that they either fail from overheating (zener diodes, thankfully, tend to fail short-circuit), or cook the surrounding circuit board to a brittle crisp.  You're also wasting energy heating up diodes that would presumably better be used cycling along.

There isn't a simple solution to this one.  I'm still testing a fairly complex one.   :-\
Title: Re: Solar gadgets + AA's
Post by: andygates on 04 April, 2011, 02:17:06 pm
Ooh now:
                    DC/DC Converter (Integrated Switch) - Buck-Boost Regulator - TPIC74100-Q1 - TI.com
                 (http://focus.ti.com/docs/prod/folders/print/tpic74100-q1.html)
Title: Re: Solar gadgets + AA's
Post by: mrcharly-YHT on 04 April, 2011, 02:37:42 pm
I used a similar buckpuck to run an LED from a variety of battery packs. The model I had took 6-32V and output a constant current of 3A.

Tried it with a bridge rectifier and the AC output from a bottle dynamo, but the dynamo didn't really have the oomf.

Very good devices, if a tad expensive.

If you look on http://uk.farnell.com/power-management (http://uk.farnell.com/power-management) there is a great system for searching for power control.

What's the voltage output from a hub dynamo?
6V hmm.

http://uk.farnell.com/maxim-integrated-products/max1672eee/converter-dc-dc-step-up-down-smd/dp/1379767 (http://uk.farnell.com/maxim-integrated-products/max1672eee/converter-dc-dc-step-up-down-smd/dp/1379767)
or
http://uk.farnell.com/texas-instruments/tps62750dskt/ic-step-down-converter-2-25mhz/dp/1755706 (http://uk.farnell.com/texas-instruments/tps62750dskt/ic-step-down-converter-2-25mhz/dp/1755706)
Title: Re: Solar gadgets + AA's
Post by: Greenbank on 04 April, 2011, 02:45:16 pm
What's the voltage output from a hub dynamo?

A hub dynamo is a constant current device. Output is 0.5A. The voltage will be proportional to speed.

Some sites quote 6W at 15mph, so that would be 12V at 15mph but it all depends on the load placed on it.

Bicycle Hub Dynamos (http://www.pilom.com/BicycleElectronics/HubDynamo.htm)
Title: Re: Solar gadgets + AA's
Post by: Valiant on 04 April, 2011, 04:48:29 pm
I'm currently working on a unit. Mains/Solar/USB > 12v 14ah Li-on pack > 2x USB outs. With the added complication that I want to be able to bulk charge the batt, and connected devices when plugged in via the mains.
Title: Re: Solar gadgets + AA's
Post by: Kim on 04 April, 2011, 04:55:55 pm
I'm currently working on a unit. Mains/Solar/USB > 12v 14ah Li-on pack > 2x USB outs. With the added complication that I want to be able to bulk charge the batt, and connected devices when plugged in via the mains.

Have you seen the MAX1737?  It has a rather spiffing input current limiting feature (intended so that wall-wart rating doesn't have to equal max system load + charging current).  Add a bit of circuitry to adjust this according to power availability, and you're winning.
Title: Re: Solar gadgets + AA's
Post by: andygates on 06 April, 2011, 12:57:09 pm
I used a similar buckpuck to run an LED from a variety of battery packs. The model I had took 6-32V and output a constant current of 3A.
Was that a commercial device?
Title: Re: Solar gadgets + AA's
Post by: mrcharly-YHT on 06 April, 2011, 01:07:50 pm
yup - 'buckpuck' is a trade name.

I had a luxeon led - erm I said 3A output, that was wrong, it was 1A. the led was 3W.

Had a couple of battery packs - 7.2 and 9.6v - just plug them into the buckpuck and it drove the led at a constant current.
Title: Re: Solar gadgets + AA's
Post by: andygates on 08 April, 2011, 11:10:07 am
Cunning stuff! Alas constant current isn't what I want, but they're clever.

Shifty pointed me to this at Farnell:
MURATA POWER SOLUTIONS|LSM2-T/6-W3N-C|CONVERTER, DC/DC, 6A 5V VARIABLEL | Farnell United Kingdom
 (http://uk.farnell.com/murata-power-solutions/lsm2-t-6-w3n-c/converter-dc-dc-6a-5v-variablel/dp/1694776)

...it looks ace, but it also has confusing specs, listing output voltage twice, once as a range and once as 5v.  Any ideas?
Title: Re: Solar gadgets + AA's
Post by: mrcharly-YHT on 08 April, 2011, 11:19:11 am
I think this is what you need:

http://www.farnell.com/datasheets/74506.pdf (http://www.farnell.com/datasheets/74506.pdf)

"This device provides a constant output voltage for
inputs that vary above and below the output voltage. It has
a 1.8V to 11V input range and a preset 3.3V or 5V output.
The output can also be set from 1.25V to 5.5V using two
resistors."

Output is only 0.3A, but that's ok for charging.

http://uk.farnell.com/maxim-integrated-products/max1672eee/converter-dc-dc-step-up-down-smd/dp/1379767 (http://uk.farnell.com/maxim-integrated-products/max1672eee/converter-dc-dc-step-up-down-smd/dp/1379767)
Title: Re: Solar gadgets + AA's
Post by: redshift on 08 April, 2011, 12:05:28 pm
Mrcharly is probably nearer the mark - albeit you'll need to put a little board together.  On closer inspection the Murata seems to require a different range from that shown in its headline spec - for 5V out, you need 8.3-13.2V in which is outside your working range - the 2.4-5.5V in range is only for 3.3V out.  It's more for CPU supply than ad hoc chargery.

Although - if you've already got the clever charger end, and you're only looking for regulation of the output from the panel, then maybe the Zener idea is the simplest? 

I'm definitely out of the loop on this one - I haven't needed to fiddle with components for so long now that I'm way out of touch with what's out there.  I think I'll go back to my leather work - at least this year's products are similar to last year's...  ::-)
Title: Re: Solar gadgets + AA's
Post by: andygates on 08 April, 2011, 02:06:57 pm
The problem I have with the Zener is that it wastes that high sunny-day power.  I'd rather use that to charge batteries!
Title: Re: Solar gadgets + AA's
Post by: andygates on 10 April, 2011, 05:03:35 pm
Heh. The Y-shaped cable that came with the charger is a perfect fit for the panel that arrived Friday (Lady Ada = FAST).  What's the worst that could happen? :demon:
Title: Re: Solar gadgets + AA's
Post by: andygates on 12 April, 2011, 09:09:34 am
First pass says that whoever said "don't worry about overpower" was right. 

Now, I need a South Pointing Chariot and a phototropic gimbal!  :demon:
Title: Re: Solar gadgets + AA's
Post by: frankly frankie on 12 April, 2011, 10:07:18 am
Heh. The Y-shaped cable that came with the charger is a perfect fit for the panel that arrived Friday (Lady Ada = FAST).  What's the worst that could happen? :demon:

Wrong polarity?
Title: Re: Solar gadgets + AA's
Post by: andygates on 12 April, 2011, 10:28:41 am
Apparently not.  Instead the standard UK solar experience -- "is it working?" and vague disappointment!   :thumbsup:
Title: Re: Solar gadgets + AA's
Post by: andygates on 12 April, 2011, 02:03:43 pm
Why, Ambassador, with this little green "charged" light, you are spoiling us!
Title: Re: Solar gadgets + AA's
Post by: andygates on 19 April, 2011, 07:31:47 pm
Learning curve: The Awesome Charlotte Charger [tm] has a big fat button that gets bumped from charge to discharge mode in bags unless you're lucky or careful.  Bombing descents down lanes upset careful packing schemes, so several times I've found that my cells aren't charged because I'm in discharge mode.

The solution?  A molly-guard (http://www.catb.org/jargon/html/M/molly-guard.html) to prevent the button being pressed by accident quite so often:  Twitpic - Share photos and videos on Twitter  (http://twitpic.com/4mw3vk)

(yay Dremel, hot glue and a bent spoke :thumbsup: )

Title: Re: Solar gadgets + AA's
Post by: Kim on 19 April, 2011, 08:42:58 pm
The less than awesome Kim charger has the same problem, as I mentioned upthread:

I discovered the SCH600F (http://www.microbatt.co.uk/product_info.php?cPath=34&products_id=55) charger [...] It needs minor fettling to make it touring-ready, in the form of disconnecting the 'refresh' button internally, as that's just going to get knocked and waste all your valuable charge, and the addition of a Mk 1 elastic band to hold the battery compartment flap shut.

Our different approaches to this problem probably say something about our respective fettling psychologies.
Title: Re: Solar gadgets + AA's
Post by: andygates on 19 April, 2011, 10:13:02 pm
Not exactly: my button needs to be up, not down, or I'd be using the Mark I Postie Special elastic band as well! 

(plus I'd been looking for an excuse to unbox the mini glue gun, and Firefly prop guns must wait until I get back from LEJOG ;) )
Title: Re: Solar gadgets + AA's
Post by: Kim on 20 April, 2011, 01:54:44 am
Not exactly: my button needs to be up, not down, or I'd be using the Mark I Postie Special elastic band as well! 

So does mine.  The elastic band is to stop the batteries falling out.
Title: Re: Solar gadgets + AA's
Post by: Feline on 20 April, 2011, 02:10:37 am
I had the same problem with my Dahon Reecharge when it was in my bar bag, and unfortunately it's charge on/off button is of the little round button you press once for on and again for off kind, so no elastic band pingfuckit fettlage would do the trick. Having it strapped to my head tube has worked though, it hasn't got knocked at all as yet. I would really like to disable the button internally, because there is really no reason to ever turn it off. If there is no current coming in anyway then it doesn't matter if it is on or off, but if there is a current coming in and it is off then the modulator gadget thingy down the line can get fried.

The switch is a bit of a liability, and to make matters worse the green led light that is on when it is charging can hardly be seen at all in daylight, which is when I need to see it because I run my light instead during the night  :facepalm:
Title: Re: Solar gadgets + AA's
Post by: andygates on 20 April, 2011, 06:53:41 am
It's odd that these portable rufty-tufty chargers don't come with a little sliding door to secure the buttons away, eh?
Title: Re: Solar gadgets + AA's
Post by: Charlotte on 20 April, 2011, 08:06:10 am
Genius idea, I'll be effecting a similar molishment on my battery pack at some stage as I've had the swichy-onny-innada-pannier problem already.

Yet another use for Sugru (https://sugru.com/), I think.
Title: Re: Solar gadgets + AA's
Post by: thing1 on 20 April, 2011, 12:40:09 pm
Aha! A Freeloader add-on Freeloader AA/AAA Battery Charger (http://www.thesolarcentre.co.uk/products/Freeloader_AA_AAA_Battery_Charger-114-5.html) ... but the Freeloader's construction shouts "break me! drop my bits in the road!" to me.


Correct. It has several serious drawbacks:
1/ the oh-so useful built in torch has a whopping great push button that is bound to drain the batteries if left at the bottom of a bag (stupid when it *also* has a slide switch for the LED)
2/ the power out connector is a proprietary easy-to loose cable
3/ the power out connector fairly quickly worked loose and became unreliable
4/ attempting to open the case to fix the above points was a fairly destructive process
5/ it won't reliably charge and be charged at the same time
6/ the battery compartment is a bit tight for the new-school oversized rechargeable AAs (but this is really the battery's fault)
7/ it gets very hot when charging.

On the plus side it is very small and (point 3 & 4 notwithstanding) fairly robust.

I've just received a Powerboost pro2 (http://www.memorybits.co.uk/shop/clearancelimited/nexxus-powerboost-pro-2-portable-emergency-usb-n21gk/11770) charger. So far so good, it seems to not suffer most the issues above (but not yet tried 4 or 6!)

EDIT: I do also have the Extreme 4 battery charger. Not so keen on that one for touring as it's so much bigger, the batteries don't stay in when shaken, and again uses a strange USB cable.
All these chargers suffer the problem you have to charge in pairs; not ideal when all head torches seem to take 3 AAAs.
Title: Re: Solar gadgets + AA's
Post by: Kim on 20 April, 2011, 01:38:30 pm
All these chargers suffer the problem you have to charge in pairs; not ideal when all head torches seem to take 3 AAAs.

Hence the SCH600F.

It's naff, but it'll charge cells independently.
Title: Re: Solar gadgets + AA's
Post by: thing1 on 20 April, 2011, 01:44:36 pm
All these chargers suffer the problem you have to charge in pairs; not ideal when all head torches seem to take 3 AAAs.

Hence the SCH600F.

It's naff, but it'll charge cells independently.

O! I C.

I didn't realize they had two models. I have this one Extreme SCH500F AAA/AA Battery Charger (http://www.rapidbatteries.com/Extreme-AAA-AA-SCH500F-battery-charger.html)

on balance I decided for the head torches I could probably make myself live with buying new batteries. We never needed to change them once in over 2 months on the road..... (but a lot of that was mid-summer with 18+ hours daylight...)
Title: Re: Solar gadgets + AA's
Post by: andygates on 20 April, 2011, 02:00:01 pm
Damn, the 600 is qualitatively better.  Poop and gadget shopping.  :P
Title: Re: Solar gadgets + AA's
Post by: Kim on 20 April, 2011, 02:21:45 pm
Damn, the 600 is qualitatively better.  Poop and gadget shopping.  :P

I did say.  In several places.   :facepalm:

What it won't do is act as a battery pack to provide USB power.
Title: Re: Solar gadgets + AA's
Post by: thing1 on 20 April, 2011, 02:45:58 pm
Oh, so it's pretty similar to the BL700 (http://www.batterylogic.co.uk/technoline/technoline-BL700.asp) then? (Sorry if you already covered all this)
I like the Battery Logic one, only drawback is the LCD display is slowly failing element by element on mine.


And darn and blast it! The power monkey won't simultaneously charge and be charged either! I swear someone said it worked well for that. Be jeez, it seems I'm cursed to spend my whole life forever buying these wretched things and discovering their shortcomings.
Title: Re: Solar gadgets + AA's
Post by: Kim on 20 April, 2011, 02:58:00 pm
Oh, so it's pretty similar to the BL700 (http://www.batterylogic.co.uk/technoline/technoline-BL700.asp) then? (Sorry if you already covered all this)

I don't own one, but the BL700 appears not to be made of cheese.  I'm also not sure about its power requirements.  The SCH600F will run on 5V at USB spec currents while charging cells independently.  I haven't yet found anything else that will.
Title: Re: Solar gadgets + AA's
Post by: Charlotte on 20 April, 2011, 03:17:34 pm
I have a BL700 and far from being made of cheese, it is in fact made of geeky battery WIN.

But it's a desktop device and not really the sort of thing I'd take touring
Title: Re: Solar gadgets + AA's
Post by: andygates on 20 April, 2011, 03:31:02 pm
Simultaneous battery and gadget charge seems to just not be done. I'm going for draining or swapping my batteries when it's dark. ;)
 
Title: Re: Solar gadgets + AA's
Post by: thing1 on 20 April, 2011, 03:42:06 pm
The only one I know that declares it can do both charging and supplying at once is the B&M reservoir (link (http://www.bumm.de/produkte/e-werk-und-zubehoer/pufferakku.html)) but that's extremely expensive for a relatively low capacity.
Title: Re: Solar gadgets + AA's
Post by: andygates on 20 April, 2011, 06:06:56 pm
If it'll go both ways (ooer madam) then capacity won't matter so much because you'll be charging on the go.  I think.

Looks like I'll have to take the 2-cell phone chargette as well as big bertha, as bertha won't charge devices with only 2 cells loaded.  The "two in the phone, two in the gps/camera/dancing flower" model needs that.  Ah well, it's tinylight.
Title: Re: Solar gadgets + AA's
Post by: andygates on 03 May, 2011, 04:51:12 pm
Of course, what happens next is that the gadget you're charging has a sulk, ignores any chargers, and runs flat.  BAH! >:(  Only just got the contacts onto the SIM and the device backed up to SD before it died.

What's that survival trope about preps?  "Two is one and one is none"?  Time to hit the backstop plastic. 
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 13 May, 2011, 12:20:04 pm
does this make sense for example....

http://i143.photobucket.com/albums/r154/n4zou/lights/DynamoUSB-2.jpg

My reading suggests the designer was using the impedance of the batteries to regulate the current to the USB rather than as a battery charger per se..., but battery charging a side benefit....  If I arranged the 4 NiMH in a battery case that's compatible with the Hope - maybe the one with PP3 connectors ?

Ach, I wouldn't plug my shiny smartphone into that.  That 6V nominal battery voltage is way outside USB spec.

As a circuit for charging batteries it'll work fine though.  They'll just start to cook (but relatively slowly, as it's not all that much power) when they're full.

/ snip /

There isn't a simple solution to this one.  I'm still testing a fairly complex one.   :-\


Would it be 6V though ?    Isn't the nominal voltage off NiMh something like 1.2V each so 4.8V for 4 ?
I could be all wrong here....

Title: Re: Solar gadgets + AA's
Post by: Kim on 13 May, 2011, 12:33:43 pm
Would it be 6V though ?    Isn't the nominal voltage off NiMh something like 1.2V each so 4.8V for 4 ?
I could be all wrong here....

Fair point, until you bung a set of Duracells in on the third cloudy day.

Mind you, the bottom end of USB spec is 4.75V, so it's not going to stay in spec for long.
Title: Re: Solar gadgets + AA's
Post by: Polar Bear on 14 May, 2011, 02:54:08 pm
And darn and blast it! The power monkey won't simultaneously charge and be charged either! I swear someone said it worked well for that. Be jeez, it seems I'm cursed to spend my whole life forever buying these wretched things and discovering their shortcomings.

Portapow (http://www.portablepowersupplies.co.uk/portapowPremium.htm) claim that you can do the simultaneous charging bit.(the premium pack at least).
Title: Re: Solar gadgets + AA's
Post by: thing1 on 15 May, 2011, 10:11:10 am
Portapow (http://www.portablepowersupplies.co.uk/portapowPremium.htm) claim that you can do the simultaneous charging bit.(the premium pack at least).

I found their description a bit vague, but I could never get my PortaPow premium to both supply power and charge itself up at the same time.
Title: Re: Solar gadgets + AA's
Post by: Polar Bear on 15 May, 2011, 10:22:24 am
I'm going to experiment with mine later.   I'll run it and the phone down then plug first the phone, then the charger.

I had a Freeloader which claimed that it too could multi task.  It blew something inside when I tried it.    :(    Appropriate name methinks...
Title: Re: Solar gadgets + AA's
Post by: Polar Bear on 16 May, 2011, 09:43:15 pm
I'm going to experiment with mine later.   I'll run it and the phone down then plug first the phone, then the charger.

I have not been able to conclusively answer this question yet.   I'd say from my observations that it was not simultaneously charging the phone through the battery as well as the battery itself. 
Title: Re: Solar gadgets + AA's
Post by: Polar Bear on 16 May, 2011, 09:47:18 pm
Actually, sod it.  I've emailed Portapow and asked them. 
Title: Re: Solar gadgets + AA's
Post by: Feline on 16 May, 2011, 10:00:58 pm
I know this is wrong thread for this, because it's not solar, but my dyno hub charger (Dahon Reecharge) can both charge up and power/recharge something simultaneously. I've been utilising this to the full on the longer Audaxes.

I start the ride in the morning with a fully charged Garmin and also a fully charger Reecharge (it has a mains charger socket too) and run the Garmin as normal from it's own internal battery.
At about 5pm I plug in the Garmin in to fully recharge it at the same time as turning on the current from the hub to the Reecharge battery pack.
By the time it's starting to get dark I have a fully charged Garmin and Reecharge. I then unplug the Garmin, turn off my reecharge switch and let my hub power my light (the light has it's own auto sensor switch and is left permanently switched on senso). I run the Garmin with backlight on constantly, and when it eventually says it's battery is getting low I plug it into the Reecharge again (at this point not connected to the hub) and allow it to be powered/recharged for the rest of the night.
When day breaks I find the Garmin is at least 3/4 charged and the Reecharge still has some charge stored, so if I was on a multi-day event I could just turn the hub back on at this point and recharge it all to start over.
It takes a little bit of thought process to do this but even on PBP I think I will manage. The only thing I found I had to do was molish a micro switch from Maplins components so I can turn the cable from the hub to the Reecharge on and off easily from the bars. This is the only safe way of stopping the reecharge receiving current when you are using your light instead, because the current modulator unit needs to send incoming current somewhere or it fries it's own innards. Dahon haven't really thought this through because in theory you would be constantly fiddling with spade connectors at your hub which is full of FAIL.
Title: Re: Solar gadgets + AA's
Post by: thing1 on 17 May, 2011, 10:53:15 am
I know this is wrong thread for this, because it's not solar, but my dyno hub charger (Dahon Reecharge) can both charge up and power/recharge something simultaneously. I've been utilising this to the full on the longer Audaxes.

Opps yes I'm guilty of side-tracking this thread too  :-[

I hadn't spotted the ReeCharge, thanks for mentioning it.
From the description, it seems very similar an integrated version of the B&M E-Werk and Cache battery, but slightly higher capacity and includes a wall adapter. Hmmmm.

One other question:
This is the only safe way of stopping the reecharge receiving current when you are using your light instead, because the current modulator unit needs to send incoming current somewhere or it fries it's own innards. Dahon haven't really thought this through because in theory you would be constantly fiddling with spade connectors at your hub which is full of FAIL.

Ugh yuck. Is this circuit frying something mentioned in the manual, or through bitter experience? Seems odd that having an additional load on the hub should cause problems down-stream in the charger/ voltage regulator.
Title: Re: Solar gadgets + AA's
Post by: LittleWheelsandBig on 17 May, 2011, 11:25:54 am
HK tried a Reecharge in parallel with a Solidlights driven from a Shimano dynohub for a while and has quit using the Reecharge.  She was getting less than optimal performance from both the battery and the headlight.  Feline's bodge overcomes most of the problem but HK wanted a plug-and-play system, not something that needs management.  We might consider solar options if we lived in a coutry with more sunshine.
Title: Re: Solar gadgets + AA's
Post by: Kim on 17 May, 2011, 02:27:01 pm
Ugh yuck. Is this circuit frying something mentioned in the manual, or through bitter experience? Seems odd that having an additional load on the hub should cause problems down-stream in the charger/ voltage regulator.

Sounds more like the use of the light is a red herring, and it's the usual zener clamp cooking itself when you go particularly fast for any length of time problem  :-\
Title: Re: Solar gadgets + AA's
Post by: Feline on 17 May, 2011, 02:54:51 pm

Ugh yuck. Is this circuit frying something mentioned in the manual, or through bitter experience? Seems odd that having an additional load on the hub should cause problems down-stream in the charger/ voltage regulator.


I think it's something that Dahon perhaps didn't realise when they designed the product, because there is a warning sheet slipped into the package in addition to the instructions telling you not to disconnect the Reecharge battery unit and leave the modulator (which is supposed to be fork mounted and permanently fitted to the bike, connected.

Personally I wanted the option of leaving the spades at the hub permanently connected via piggyback spades along with my light, but removing the Reecharge from the bike or simply turning it off to reduce resistance in the hub whenever I liked.

As Kim mentions, this requires a little bodge involving some kind of connectors in-line (Tamiya connectors from Maplins are ideal) and also a switch in-line before the current regulator.

I have got round this by keeping both the modulator and the Reecharge inside a small bar bag and having a tiny Maplins switch attached to the outside of the bag so I can turn things on and off at will. I'm not all that good at electronic fettling but I managed it with a cheapo soldering iron and a bit of spare dynamo lighting cable.

It is possible to run a dyno light and the Reecharge at the same time so long as you're doing a reasonable speed, but it isn't ideal and just isn't really necessary to since you can make sure your Reecharge is fully charged at dusk and the combo of a fully charged Garmin and a fully charged Reecharge battery pack can easily see you through the night. The Reecharge can charge anything with a USB cable, so handy for phones and ipod etc. if your touring. I can even charge my Kindle :)
Title: Re: Solar gadgets + AA's
Post by: petes46 on 04 June, 2011, 10:59:20 am
I'm going to experiment with mine later.   I'll run it and the phone down then plug first the phone, then the charger.

I had a Freeloader which claimed that it too could multi task.  It blew something inside when I tried it.    :(    Appropriate name methinks...

I've got a Solar/Power Gorilla combination.  It's a bit big for most people but I rather like gadgets and that means charging things.  I tried the experiment of plugging the battery unit into the solar panel and charging something, my phone I think, from the battery unit.  As far as I can tell, the result depends upon the brightness of the light.  In standard British conditions, the phone charged (slowly) but nothing changed with the battery pack.  In bright sunlight, both units received some charge.

During my recent outing, I was carrying the solar panel strapped to the top of the trailer with the battery pack tucked inside.  Seemed to work well (unless it was pouring with rain!) and I charged the bits that needed charging in the evening / overnight.  If I stopped early enough then I could use the panel to charge one item and the battery pack to charge another.  Greedy, what?

I'd still like to have the backup of a dynamo so I've been watching Kim's thread with interest.
Title: Re: Solar gadgets + AA's
Post by: Polar Bear on 04 June, 2011, 11:04:44 am
I'm going to experiment with mine later.   I'll run it and the phone down then plug first the phone, then the charger.

I have not been able to conclusively answer this question yet.   I'd say from my observations that it was not simultaneously charging the phone through the battery as well as the battery itself.  

Actually, sod it.  I've emailed Portapow and asked them.  

And Portapow say that you need at least 1A output from your charger for simultaneous charging and running a gadget.   I guess that I need to buy another usb charger, and, it's unlikely that I'll be able to charge and power simultaneously from the dynohub whilst cycling.  

Having tried a 1A charger as suggested my smartphone can eat battery faster than the Portapow can charge it in this configuration. :o  ::-)  :D
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 06 June, 2011, 02:32:17 pm
Aldi .  9th June.  

      ALDI - Thursday Special Buys 9th June 2011     (http://www.aldi.co.uk/uk/html/offers/special_buys3_19246.htm?WT.mc_id=2011-06-06-13-13)

(http://www.aldi.co.uk/uk/media/offers/01_11_week_23/Product_detail_Wk23T32.jpg)

Wonder how good that will be ?    Worth  £12.99  ?
 
Title: Re: Solar gadgets + AA's
Post by: Somnolent on 06 June, 2011, 02:52:58 pm
Another product I came across recently was

M172 Bicycle charge controller USB (Mini B) (http://www.kemo-electronic.de/en/House/Home/M172-Bicycle-charge-controller-USB-Mini-B-.php)

Available in UK here  M172 Bicycle charge controller USB (Mini B) (http://www.kemo-electronic.de/en/House/Home/M172-Bicycle-charge-controller-USB-Mini-B-.php)

Reading this   http://www.crazyguyonabike.com/reviews/board/message/?thread_id=213301&page=1  it sounds like the output voltage control was not up to the job on USB devices, but what I rather like about the concept was the integrated switch between light and USB.   

It sounds like it would fulfil my #1 criteria of charging AAs if one connected up the appropriate USB battery charger like the one Kim recommends upthread - presumably that wouldnt care too much about occasional out of spec voltage excursions ?
Title: Re: Solar gadgets + AA's
Post by: andrewc on 19 June, 2011, 12:47:46 pm
Powermonkey Extreme (https://powertraveller.com/iwantsome/arrivingsoon/000382/) now appears to be available.  Not cheap at £120, though use your CTC discount at Cotswold and it comes down to £102.

On my recent Scottish trip my plan to sneak power from campsite shower blocks was frustrated. None of them had available 3 pin outlets, however they all had 2 pin shaver sockets (in the gents at least!)  Annoyingly my travelling USB plug (http://www.amazon.co.uk/gp/product/B003UP11Y6/ref=oss_product) wouldn't fit them. The 2 pin continental plug is just slightly different from a shaver plug  >:(





Title: Re: Solar gadgets + AA's
Post by: thing1 on 19 June, 2011, 05:27:23 pm
Pwermonkey Extreme (https://powertraveller.com/iwantsome/arrivingsoon/000382/) now appears to be available.  Not cheap at £120, though use your CTC discount at Cotswold and it comes down to £102.

Looks like that has a few improvements. Proper USB out socket rather than relying on silly barrel connectors and those cumbersome / easy to loose adapter tips. And "Users can also simultaneously use the solar panel to charge the powermonkey-eXtreme whilst it is charging their device" sounds promising. Wonder if that's only from the  panel (?) or would work from mains too.

    Battery weight: 242g (c.f. 83g for the explorer version). (From cotwolds outdoors)

It's a bit of a brute.   But then...

   Output: USB port: 5V 700MAh ad DC port 2.1A

700 MEGA amp hours? 3.5 Giga Watt hours. Sounds enough to send a Delorean through time and space.
Yeah, that'll do.

(I think they actually mean "USB port: 5V 700mA.")


Title: Re: Solar gadgets + AA's
Post by: Charlotte on 19 June, 2011, 10:05:44 pm
You only need 1.21 gigawatts for that  ;D
Title: Re: Solar gadgets + AA's
Post by: Kim on 20 June, 2011, 01:05:04 am
You're not thinking fourth dimensionally!  As anyone who watched the third movie knows, it's 1.21 gigawatts to power the time circuits and the flux capacitor.  To move though space at speeds in excess of 88mph the DeLorean still needs the internal combustion engine, a push from a friendly locomotive, or the hover conversion's unspecified (but presumably vulnerable to lightning damage) power source.   ;D


9000mAh battery though.  That's more like it.   :thumbsup:
Title: Re: Solar gadgets + AA's
Post by: thing1 on 20 June, 2011, 09:02:31 am
You only need 1.21 gigawatts for that  ;D

 ;D

Well..... 3.5 GWh @ 1.21 gigawatts is getting on for 3 hours of sustained time travel. Perfect! (although I'm slightly nervous in my usage of 'time' to measure a quantity of movement through 'time')
Title: Re: Solar gadgets + AA's
Post by: Greenbank on 20 June, 2011, 09:42:53 am
9000mAh battery though.  That's more like it.   :thumbsup:

9000mAh battery = 460g (according to that page but I'm guessing that includes cables/etc), £102 with CTC discount

or, 3 Portapow battery packs (3400mAh, 120g, £31.50 each) = 10200mAh, 360g, £94.50

But only the Powermonkey Extreme has the 2.1A output that the iPad requires.

For PBP I'm still unsure as to whether I go for a e-Werk or just another Portapow battery pack (each one can do a 600). The chances of me reusing the e-Werk in the next few years is almost none, so it's probably better to hold of buying one until the price has come down or the technology improves slightly. A second Portapow batterypack will be lighter than the e-Werk plus all of the cables too.

Looks like I've just talked myself into another Portapow battery pack.
Title: Re: Solar gadgets + AA's
Post by: thing1 on 20 June, 2011, 12:25:02 pm
I think the 460g would include the solar panel too. That's why I went with 242g from Powertraveller Powermonkey Extreme (http://www.cotswoldoutdoor.com/index.cfm/fuseaction/products.detail/code/A8110026)

It's _unlikely_ we'll use the e-Werk for PBP... if we don't you're welcome to borrow it.

Between signage and StokerNavTM I'm not that worried about GPSing it. I'll likely just carry the Garmin as a backup.
The phone on the other hand would be nice to leave powered so it can Latitude and Tweet and whatnot as we go. I'm not sure I want to tamper with the lighting system for such frivolities though.

(Must every thread turn into PBP preparation discussion?  ::-)  ;)  ;D )
Title: Re: Solar gadgets + AA's
Post by: andrewc on 04 August, 2011, 12:23:13 am
http://www.youtube.com/watch?v=u6l8V2SjDv4 (http://www.youtube.com/watch?v=u6l8V2SjDv4)

A brief  demo of the PowerMonkey Extreme and another review  here (http://richard.mackney.com/powermonkey-extreme-mobile-power-review)
Title: Re: Solar gadgets + AA's
Post by: andrewc on 13 August, 2011, 10:53:29 am
Another large solar panel aimed at the outdoor user.  Works out at £66 inc shipping from Amazon.com , though if customs pick it up you may get hit with duty & admin fees on top.   Lots of enthusiastic reviews but one comment that they have an active marketing programme...

http://www.crazyguyonabike.com/doc/?o=1r4vFZo&doc_id=9258&v=EH

http://www.youtube.com/watch?v=Eg2U6tF7Rqw

And this looks like a nicely chunky battery pack New Trent IMP1000 (http://www.amazon.co.uk/New-Trent-iCruiser-IMP1000-Blackberry/dp/B004CHMP50/ref=sr_1_1?ie=UTF8&qid=1313228936&sr=8-1)