Author Topic: Which battery pack?  (Read 2736 times)

Kim

  • Timelord
Re: Which battery pack?
« Reply #25 on: September 20, 2018, 06:42:01 pm »
I’ve had a Technoline BL700 for many years, does a great job, not sure if they are still available.

Yeahbut they're huge and run on a high-current 3V power supply.  Not something you're going to carry on a tour.

(BL700 is an excellent charger for home use.)


An often overlooked option for touring is that with the right settings the B&M e-Werk can be used to charge some combinations of cells directly, so you could use this to charge a pair of NiMH cells with a simple battery holder.  Pretty lightweight!
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Which battery pack?
« Reply #26 on: September 21, 2018, 12:21:55 am »
I’ve had a Technoline BL700 for many years, does a great job, not sure if they are still available.

There's the improved BL700N model, which looks great for home use, but doesn't look like it can be USB-powered and looks relatively large and heavy to carry on the bike.

http://www.batterylogic.co.uk/technoline/technoline-BL700.asp
Old enough to know better, but young enough to do it anyway

Re: Which battery pack?
« Reply #27 on: September 21, 2018, 07:56:10 am »
The lightest AA charger I have which travels with me when I need one is the 7DayShop one. Current version appears to be a revamp of the one I have in cream plastic with a flap. crucially it is fed electrons by an IEC C7 (figure of 8 ) lead straight from the mains, and has separate charging circuits for each cell and it weighs 104g.

(Model number of mine is 808LCD as https://www.amazon.co.uk/7dayshop-Intelligent-Battery-Charger-Display/dp/B002IW5LX4)

ETA one on the bay of thieves

Kim

  • Timelord
Re: Which battery pack?
« Reply #28 on: January 13, 2019, 09:49:31 pm »
Follow-up on the subject of portable charging...

On the logic that the lightest charger is the one you're carrying already, I molished this adaptor for my e-Werk:



The idea being that if you set the output to 2.8V with an appropriate current limit[1], it can safely be used to charge a pair of NiMH cells in series.  Positive to positive (red wire on the battery clip to white wire on the e-Werk output cable), for those playing along at home.

Plus points:  It works, is compact and weighs very little, and potentially doubles as a convenient way to carry spare batteries.  Relatively unlikely to break from rattling around in your bag, unlike anything with a solidly-attached USB A plug on the end, and the batteries don't fall out.

Gotchas:  By stopping at 1.4V (which is necessary to avoid damaging the cells, this isn't measuring delta-V or temperature), the battery only gets to about 80% charged.  It's also fairly slow - I measured a little over 300mA into a pair of cells depleted to the point where the eTrex moans about low battery.  The current tails off as the voltage rises.

And obviously you need to power your e-Werk.  Riding your dynamo-equipped bike is traditional[2], but it's actually specified for both AC and DC input across a wide range of input voltages.  You could, for example, connect it to a 12V solar panel.  Or an e-bike battery.  And, interestingly, USB's 5VDC is just barely sufficient for this 2.8V charging, although the peak current is limited if there's any drop-out at all.

(This direct-connection-to-a-battery approach will work for other combinations of cells and chemistries, check the manual for what's safe.)

Is it worth it?  Possibly.  I reckon you'd get better results with 18650 Lithium-ion cells.


[1] Keep it below 1C, which in practice means you can turn it all the way up for high-capacity AAs, but you might want to limit to 0.5A or so for AAAs.
[2] One advantage of directly charging batteries is they don't give a stuff about stop-start charging.
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Which battery pack?
« Reply #29 on: January 27, 2019, 09:16:00 pm »
IME it's not so much the rain, as the risk of the MicroSD card falling out on account of the crappy holder.

Yes I lost one once. But that's what that old cyclist standby Duct tape is for. My Etrex 20 has a small bit in there permanently.

Re: Which battery pack?
« Reply #30 on: January 27, 2019, 09:18:41 pm »
i wouldn't recommend using usb changing all the time as vibration will damage the contacts in the socket and the unit will become unusable. i've had this on my gps, and now only use the cable to charge on the go when really necessary.

On the Etrex it doesn’t charge, just powers the unit via the USB.

It doesn't make any difference to ZigZag's point - the issue is the socket being in use during riding.

I've been using rechargeable batteries in Etrex GPS devices since about 2006. They're a good option despite my earlier caveat. Use good quality batteries and a good charger if going this way.

Yes - I don't think usb sockets are up to this sort of thing. Pretty damn sure they weren't designed with this sort of use in mind.

I use rechargeables in my Etrex20 - works fine - feel no need to carry, let alone plug in, a power bank - bigger and heavier than a set or two of spare AAs