Building a Battery Pack

Tubamanandy

Esteemed Pedelecer
Feb 12, 2014
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Not for my e-bikes, but, I need to build a 12v battery pack using LifePO4 cells with at least 100Wh capacity.

Can anyone recommend the best cells to use and where to source the bits (ideally in UK) ? The cells need to be the deep charge type and I will need to source a charger and battery box of some sort. Hopefully, they should be capable of being charged in about 2hrs at about 6 amps. In use, the draw on the battery will be about 5 watts/hr I believe.

The pack is actually for a twin-car camera setup I have
 
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Deleted member 4366

Guest
I've got a few questions:

Why LiFePO4, when you can get smaller lighter, easier to get hold of and handle 18650 cells?

All the cameras I've used have an adapter that cuts the voltage down from 12v to 5v for the camera to power it through a micro USB lead. Wouldn't it be better to provide the 5V directly?

Why do you want a separate battery when you already have a massive 12v battery in the car?

These powerpacks are good for USB power supply. You just clip in your 18650s and everything is done for you. 6 Panasonic cells will give you about 12 Ah at 5v. You have to look at the camera spec to see how much current it uses. If you get two, you can use one while charging the other.
http://pages.ebay.com/link/?nav=item.view&id=261954488228&alt=web
 

Tubamanandy

Esteemed Pedelecer
Feb 12, 2014
267
38
62
Why LiFePO4, when you can get smaller lighter, easier to get hold of and handle 18650 cells?

The battery pack I want to build is really an expansion pack to match a very expensive battery pack that I have already purchased - it is made from LifePO4 cells, I'm simply trying to match it (except for the gorrendouys price) :)

All the cameras I've used have an adapter that cuts the voltage down from 12v to 5v for the camera to power it through a micro USB lead. Wouldn't it be better to provide the 5V directly?

My camera units run at 12V - I have been using a couple of devices to stop the battery dropping too low but they really are not effective - a separate battery pack is what I have purchased (just need to build an expansion pack for it)

Why do you want a separate battery when you already have a massive 12v battery in the car?

See above, was causing allsorts of issue using my existing car battery mainly with the fancy stop/start system (battery going too low).

These powerpacks are good for USB power supply. You just clip in your 18650s and everything is done for you. 6 Panasonic cells will give you about 12 Ah at 5v. You have to look at the camera spec to see how much current it uses. If you get two, you can use one while charging the other.
http://pages.ebay.com/link/?nav=item.view&id=261954488228&alt=web

This is what I have purchased:-

http://www.blackboxmycar.com/collections/dashcam-battery-pack/products/cellink-battery-b

I would simply like to build the expansion pack for it rather than purchase their pack which is expensive when you take into account postage from Canada & Import duties.