Author Topic: Powering a powerbank  (Read 2314 times)

Powering a powerbank
« on: December 20, 2019, 04:43:10 pm »
Hello all
I'm looking for the cheapest and least complicated way of powering a power bank from my Shimano dynamo.

This is for my summer touring.
So I'm not needing to power a headlamp.
I just need to keep my phone and camera topped up when I can't always access mains power.

Looking forward to your suggestions.

Ian

Re: Powering a powerbank
« Reply #1 on: December 20, 2019, 05:22:46 pm »
I used an e-werk (https://www.sjscycles.co.uk/dynamos/busch-muller-ewerk/) back when I needed to do such things. It doesn't do a bad job, but nothing compares to plugging into the grid somewhere.

quixoticgeek

  • Mostly Harmless
Re: Powering a powerbank
« Reply #2 on: December 20, 2019, 07:21:38 pm »


I use a USB-Werk. But tbh, the yield is pretty poor. You're only getting 2wh for every hour your riding.

Now You can get large power banks that can charge fast, for relatively low costs,  My 100wh Anker pack fully charges in ~6.5 hours. Finding a cafe/bar/restaurant with a power socket and putting in 15-20w while you eat lunch is far superior to the drag your dynamo will be constantly adding while you move.

You can carry a lot of lithium for the weight of a dynamo. Your power budget doesn't seem very demanding.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: Powering a powerbank
« Reply #3 on: December 20, 2019, 07:35:28 pm »
I agree with QG. Even ignoring weight and drag, the number of hours of riding on a casual summer tour might not be enough to make much headway on a decent sized power bank. and you'll be looking for a mains socket anyway.

(if you are planning to be properly off grid somewhere sunny, solar power might make more sense)

Kim

  • Timelord
Re: Powering a powerbank
« Reply #4 on: December 20, 2019, 07:40:27 pm »
Given summer, and depending on how much time you're actually going to spend actually riding, and whether you're able to keep it pointing in the direction on the sun[1], solar (say a 15W panel) can outperform dynamo power.  Most of my cycle camping over the last couple of years has been to ALC meets, where a solar panel is more useful than an E-Werk (even if I go for a day ride, I can leave the panel and powerbank doing its thing back at camp).  Of course, dynamos aren't weather dependent.

As quixoticgeek says, it's hard to beat some quality time spent with a mains socket.  Get a decent power bank that can charge at a high rate (eg. using QC3) and a compatible charger, and you can potentially make do with electrons scavenged from cafes and so on.


[1] Leaning against a tent at the optimum angle and repositioned every couple of hours beats lying flat on the ground, which beats strapped over your panniers.
Careful, Kim. Your sarcasm's showing...

Cudzoziemiec

  • Eating all the pies and drinking all the tea.
Re: Powering a powerbank
« Reply #5 on: December 20, 2019, 07:48:32 pm »
Compatible charger? Meaning what? How do you know? Well, not you, how would those less steeped in the way of the electron know? Those who thought all USB chargers were alike in their charging rate (if it's even rate we're talking about?).
Days become simply the spaces between dreams, spaces between the shifting floors of time...

Re: Powering a powerbank
« Reply #6 on: December 20, 2019, 08:01:06 pm »
Standard USB is 5 volts and limited to about 2.5 amps, so 5*2.5 = 12.5 watts, which given even a small-ish power bank can be 40Wh, means it takes 3-4 hours for a full charge.

The way round this is to increase the volts, since increasing amps makes things melty. There are two common systems for doing this - QuickCharge 3 (which uses a standard USB connector) and USB PD (which uses the newfangled USB C connector). If both devices are compatible with one of these two systems, and both support the same higher voltage, *and* you have the right cable, then they can get negotiate using a higher voltage, get more watts over the wire and therefore charge quicker.

Sadly checking which gear is compatible requires a lot of squinting at spec sheets, trusting dubious manufacturer claims and mostly trying it out and hoping for the best.

Kim

  • Timelord
Re: Powering a powerbank
« Reply #7 on: December 20, 2019, 08:08:40 pm »
Compatible charger? Meaning what? How do you know? Well, not you, how would those less steeped in the way of the electron know? Those who thought all USB chargers were alike in their charging rate (if it's even rate we're talking about?).

To charge a QC3 compatible thing (phone, powerbank, whatever) at QC3 speeds[1], you need a QC3 capable charger.  There's also Power Delivery (PD), because The Great Thing About Standards™ applies.  There are logos to befuddle the user and, particularly in the case of phones and fondleslabs, proprietary branding for the technology (eg. Motorola Turbopower is just another name for QC3).

There are also powerbanks that can charge at normal[2] USB voltage and current from more than one USB plug at the same time, which is a nasty but potentially useful bodge (if you have a high-power multi-output charger), and others that take the easy (for the designer) option and charge from some non-USB-compatible wall-wart via a traditional DC jack.  Works fine, but less ideal for touring, as you can't then use the same wall-wart to power your other USB stuff, or obtain an appropriate wall-wart for the sockets used by FOREIGNS in ABROAD, rather than mucking about with adaptors.

Also note that just because a powerbank supports QC3 or PD on an output, doesn't mean it does so on the input.  For a typical touring cyclist, the speed at which your phone can charge from your powerbank is largely irrelevant; the important thing is how fast the powerbank can charge during your cafe stop.

When I tried to buy one (some time ago now), QC3 compatible mains chargers in a folding BS1363 form-factor were surprisingly hard to come by.  I ended up with an expensive Sony one in order to get a slidy-inny earth pin.  The situation may have improved.


[1] Both QCn and PD work by having enough intelligence at both ends to enable the device to negotiate with the charger to raise the voltage above the normal USB spec, delivering more power and reducing cable losses.
[2] For arbitrary values of normal.
Careful, Kim. Your sarcasm's showing...

quixoticgeek

  • Mostly Harmless
Re: Powering a powerbank
« Reply #8 on: December 20, 2019, 08:51:14 pm »
There are also powerbanks that can charge at normal[2] USB voltage and current from more than one USB plug at the same time, which is a nasty but potentially useful bodge (if you have a high-power multi-output charger)

This is the approach I use, I have a power bank with 2 inputs, meaning I can charge it at 4A, so 20W. (https://amzn.to/2G64YZu).

I also have a number of different USB wall warts with varying numbers of outputs. As most of my use case is on the continent, I have a RAV Power 40w unit, that can do 2.4w max per channel, for a total of 40w across all 3. I plug the anker into this, and it gives me 2 spare ports for wahoo + phone. They don't weigh much and I have been known to carry 2 of them (powerbank (2 ports), phone, wahoo, inreach+, camera, light, spare light battery), depending on how little time I am planning to spend in a hotel at any given time.  For in the UK I have https://amzn.to/2EBe1iv as well as a 4 port that isn't available anymore. Saves needing to find a charger in the form factor you want, which supports the protocol you need. Also means if you lose it you can pick up any old usb wall wart from a gas station.

J



--
Beer, bikes, and backpacking
http://b.42q.eu/

Cudzoziemiec

  • Eating all the pies and drinking all the tea.
Re: Powering a powerbank
« Reply #9 on: December 20, 2019, 09:00:29 pm »
I had a look at my powerbank and couldn't see any QC3 marking, so probably not relevant for me. Though most of the stuff that's not numbers is Chinese characters. But there is a very useful pictogram telling me not to burn it. I have noticed it does seem to charge faster from some chargers than others, but that must be for some other reason.
Days become simply the spaces between dreams, spaces between the shifting floors of time...

quixoticgeek

  • Mostly Harmless
Re: Powering a powerbank
« Reply #10 on: December 20, 2019, 09:04:51 pm »
I had a look at my powerbank and couldn't see any QC3 marking, so probably not relevant for me. Though most of the stuff that's not numbers is Chinese characters. But there is a very useful pictogram telling me not to burn it. I have noticed it does seem to charge faster from some chargers than others, but that must be for some other reason.

Probably means that the power source is better quality.

There are an awful lot of crap power banks on the market. It really is an area where paying a little bit more for a named brand can be worth while. Tho one of the best units I have is sold by IKEA. The IKEA unit does tell me it's 36wh.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Kim

  • Timelord
Re: Powering a powerbank
« Reply #11 on: December 20, 2019, 09:12:21 pm »
I have noticed it does seem to charge faster from some chargers than others, but that must be for some other reason.

If you have even a passing interest in this sort of thing, you can do a lot worse than invest in one of the many basic USB power meters that are available on AliExpress/eBay and similar for a couple of quid.  It won't necessarily help you with the 'why', but it can be useful to simply determine which combinations of devices/chargers/cables work well and which are unexpectedly hopeless.  The slightly better ones will keep a running total of mAh, so you can use them to measure the real-world capacity of a powerbank, or how much it takes to fill your phone or whatever.

(If you're being really fancy, the Ruideng ones are pretty good.  I've got a UM25C, which can work out what sort of signalling voodoo is going on on the data lines, as well as making the usual measurements.)
Careful, Kim. Your sarcasm's showing...

Cudzoziemiec

  • Eating all the pies and drinking all the tea.
Re: Powering a powerbank
« Reply #12 on: December 20, 2019, 09:13:50 pm »
I had a look at my powerbank and couldn't see any QC3 marking, so probably not relevant for me. Though most of the stuff that's not numbers is Chinese characters. But there is a very useful pictogram telling me not to burn it. I have noticed it does seem to charge faster from some chargers than others, but that must be for some other reason.

Probably means that the power source is better quality.

There are an awful lot of crap power banks on the market. It really is an area where paying a little bit more for a named brand can be worth while. Tho one of the best units I have is sold by IKEA. The IKEA unit does tell me it's 36wh.

J
Confused, sorry. What probably means it's better quality? Chinese characters?
Days become simply the spaces between dreams, spaces between the shifting floors of time...

quixoticgeek

  • Mostly Harmless
Re: Powering a powerbank
« Reply #13 on: December 20, 2019, 09:17:20 pm »
I had a look at my powerbank and couldn't see any QC3 marking, so probably not relevant for me. Though most of the stuff that's not numbers is Chinese characters. But there is a very useful pictogram telling me not to burn it. I have noticed it does seem to charge faster from some chargers than others, but that must be for some other reason.

Probably means that the power source is better quality.

There are an awful lot of crap power banks on the market. It really is an area where paying a little bit more for a named brand can be worth while. Tho one of the best units I have is sold by IKEA. The IKEA unit does tell me it's 36wh.

J
Confused, sorry. What probably means it's better quality? Chinese characters?

The device you are charging the power bank from being better quality. Rather than the powerbank itself.

Bear in mind that lithium batteries are not a 100% safe product, and that they aren't unknown for their ability to spontaneously combust. Better quality tends to reduce this risk. A named brand device is likely to be a lower risk.

J

--
Beer, bikes, and backpacking
http://b.42q.eu/

Cudzoziemiec

  • Eating all the pies and drinking all the tea.
Re: Powering a powerbank
« Reply #14 on: December 20, 2019, 09:36:51 pm »
Ah, yes, okay. You did say power source. Sorry and thanks and all.
Days become simply the spaces between dreams, spaces between the shifting floors of time...

Re: Powering a powerbank
« Reply #15 on: December 20, 2019, 09:53:59 pm »
Thanks for the replies
I surmise that I really need a Solar charger
I  usually manage to scavenge some mains power. I was caught out a few times on the  last tour, especially if I was using the phone camera, and it was a stress not letting people know I was  safe.


cheers

ian

bludger

  • Randonneur and bargain hunter
Re: Powering a powerbank
« Reply #16 on: December 21, 2019, 04:04:39 pm »
While we're on the sparky chat, can anyone recommend a fast charging powerbank? My OnePlus phone can go from 0% to 100% in a out 40 minutes, I hoped there might be a powerbank that has a similar performance. I have a good powerbank but it doesn't charge especially quickly and I expect I'll want to replace it within a few years.
YACF touring/audax bargain basement:
https://bit.ly/2Xg8pRD



Ban cars.

quixoticgeek

  • Mostly Harmless
Re: Powering a powerbank
« Reply #17 on: December 21, 2019, 04:29:54 pm »
While we're on the sparky chat, can anyone recommend a fast charging powerbank? My OnePlus phone can go from 0% to 100% in a out 40 minutes, I hoped there might be a powerbank that has a similar performance. I have a good powerbank but it doesn't charge especially quickly and I expect I'll want to replace it within a few years.

Yes, the Anker one I link to above.
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: Powering a powerbank
« Reply #18 on: December 21, 2019, 05:17:42 pm »
I tend not to bother trying to charge stuff from the dynamo on tour anymore. I just use it to power my GPS and lights if I need them. I've got so much capacity now that even if I don't get a sniff of mains power for a few days, I've still got enough juice. Then when I do find power, I charge the lot in one go:

Those wonderful norks are never far from my thoughts, oh yeah!

Re: Powering a powerbank
« Reply #19 on: December 22, 2019, 09:40:53 pm »
I have one of these wending it's way to me: https://www.amazon.co.uk/Poweradd-20000mAh-Delivery-Compatible-Tablets-Black/dp/B07K1XTXRS/ref=dp_ob_title_wld I've had good performance from an earlier Poweradd so went with them again but with added USB-C and PD charging goodness. My aim is to reserve my dynohub for powering lights. The new Igaro D2 looks neat but I'm not sure I'd need it even on something like PBP or LEL.

bludger

  • Randonneur and bargain hunter
Re: Powering a powerbank
« Reply #20 on: December 24, 2019, 04:07:46 am »
YACF touring/audax bargain basement:
https://bit.ly/2Xg8pRD



Ban cars.

Re: Powering a powerbank
« Reply #21 on: December 24, 2019, 01:13:58 pm »
...

Yes, the Anker one I link to above.
cheers that looks like the mutt's

Been some other recs for power banks on another forum.  I have the old gen ankers (not the fast charge versions) and will upgrade with the ankers again on the grounds that they have been so robust. Grippy shape, compact and survived bike pack races. The light wheel indicator is really useful just need them to charge faster!
often lost.

Re: Powering a powerbank
« Reply #22 on: December 24, 2019, 01:57:42 pm »
]

Been some other recs for power banks on another forum.  I have the old gen ankers (not the fast charge versions) and will upgrade with the ankers again on the grounds that they have been so robust. Grippy shape, compact and survived bike pack races. The light wheel indicator is really useful just need them to charge faster!

I have some 3-4 yo ankers and a couple of other brands. I find they are fine for tcr-type use. They charge overnight when I'm in a hotel. I would never bother trying to to them up in a cafe.
I use 4 x 10 Ah and find they can keep me going for 3-5 days comfortably, and longer at a pinch of I mix in a few AAs.
Quicker charging would be good but I can manage fine with that set up.
What sizes do you have and what is your issue with them?

Re: Powering a powerbank
« Reply #23 on: December 24, 2019, 02:44:41 pm »
]

Been some other recs for power banks on another forum.  I have the old gen ankers (not the fast charge versions) and will upgrade with the ankers again on the grounds that they have been so robust. Grippy shape, compact and survived bike pack races. The light wheel indicator is really useful just need them to charge faster!

I have some 3-4 yo ankers and a couple of other brands. I find they are fine for tcr-type use. They charge overnight when I'm in a hotel. I would never bother trying to to them up in a cafe.
I use 4 x 10 Ah and find they can keep me going for 3-5 days comfortably, and longer at a pinch of I mix in a few AAs.
Quicker charging would be good but I can manage fine with that set up.
What sizes do you have and what is your issue with them?

I have 3 x 10Ah Frank. I wasn't getting full charge on the overnight stops though (4 hours or there about) It could be that I was using crap cables and a sub par "wall wart"
 Sometimes I'd wake up and see only a couple of additional dots on the power wheel indicator and feel uneasy.
It was on the 4 odd nights playing catchup riding through the night that the power banks weren't keeping up.
I had  couple of wall warts, one a triple, but as Im sure you know one socket in the room isn't unheard of. Set the alarm a couple of times to swap things around.
My phone (iPhone 7 plus) probably uses a lot of power and I do take a lot of photos.  7's are not fast charge capable. Rather not go to the expense of changing out a perfectly serviceable phone.
I had 4 usb light sticks on the bike too (2 on at any given time) I keep the back light on the wahoo at night.

I never ran out of juice but got v low, and thats when it gets on your mind.
often lost.

Re: Powering a powerbank
« Reply #24 on: December 24, 2019, 07:36:07 pm »
You need a decent charger, amazon ratings should steer you towards something serviceable, which should put out 1.5 - 2 amps so they charge over night. But the quickest wins would be to take a 4th power bank, and use less power (taking photos =faffing!)

EDIT from 2 minutes searching here are a couple of chargers which claim to be good for at least 2A x 4:

https://www.amazon.co.uk/Syncwire-Charger-Upgraded-Multiple-Interchangeable-White/dp/B07Q2SVG31/ref=sr_1_10?crid=19RZ2EFXLB3RO&keywords=usb+charger+4+port&qid=1577247917&sprefix=usb+char%2Caps%2C169&sr=8-10


https://www.amazon.co.uk/dp/B0773JG24W/ref=vp_d_pb_TIER1_cmlr_lp_B07Q2SVG31_pd?_encoding=UTF8&pd_rd_i=B0773JG24W&pd_rd_w=LCwGd&pf_rd_p=a5181cc2-2759-4854-b0ca-328b7b655681&pf_rd_r=3697e419-fda6-4341-9442-a923566e4449&pd_rd_r=3697e419-fda6-4341-9442-a923566e4449&pd_rd_wg=ttJeg