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Converting a dead 3s pack, to a good 2s pack

Posted: Wed Sep 23, 2015 6:29 pm
by Lee
I had two batteries with one dead cell in each.
So I decide to make them into 2s packs.
It worked a treat.
Now I have a lighter pack for my goggles. And an Rx pack.
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Re: Converting a dead 3s pack, to a good 2s pack

Posted: Wed Sep 23, 2015 7:12 pm
by Graham Lawrie
Good idea Lee:)

Re: Converting a dead 3s pack, to a good 2s pack

Posted: Wed Sep 23, 2015 8:46 pm
by Stambo
I have 3 3s packs with one dud cell each and I was going to try make 2 good 3s packs but separating the cells seems to be an issue.

Re: Converting a dead 3s pack, to a good 2s pack

Posted: Thu Sep 24, 2015 12:09 am
by cml001
Hummmm.. Interesting.

Re: Converting a dead 3s pack, to a good 2s pack

Posted: Thu Sep 24, 2015 8:13 am
by Marius
Nice. Would be nice to have seen how you did it though :)

Re: Converting a dead 3s pack, to a good 2s pack

Posted: Thu Sep 24, 2015 2:34 pm
by Lee
Stambo wrote:I have 3 3s packs with one dud cell each and I was going to try make 2 good 3s packs but separating the cells seems to be an issue.
I just pushed a blunt piece of thin plastic between the cells to release the glue.
It can be tricky, and is possible to damage the cell quite easily.
Marius wrote:Nice. Would be nice to have seen how you did it though :)
I just desoldered all the cells, removed all wires.
Then solder back together the tabs of the good cells in series.
Added back the battery lead to the first and last tabs.
Sequence for 2S is:
+ battery lead to + terminal of first cell,
- terminal soldered to + terminal of second cell,
- battery lead soldered to - terminal of second battery.

I didn't bother with a balance lead, as these are only for my goggles.

Re: Converting a dead 3s pack, to a good 2s pack

Posted: Tue Sep 29, 2015 5:20 pm
by danhampson
a friend of mine recommended the use of zippo lighter fluid to help release the adhesive between the cells, but ive not had the chance to butcher some old packs yet.