oups i dremeled my cel to deep damaged??

[want to build]

hi
I recycled cells from makita drills
when liberating the cells, i dremeled to deep .
1 Can you look at thoses cells to si if it looks safe ?

2 To be sure there is no shortcut between the positibe pole and the negative enveloppe, i tough about adding a bit of this glue to avoid problems is it a good idea?

my motor controller only require 7 amps to work and the place i look my bike is visited by thiefs (downtown) so i decided to build a mini pack just for small support. ithe mini pack is 13s2p. each paralel group is made of 1 vtc3 and 1vtc4. see below
3 what do you think about that? the motor will be xiongda 2 speed hub motor.
tx

4 one of my big fear is that when i solde copper on the positive tip, tin drops (over dorps) on the side of the positive pole and make contact with the enveloppe negative. how to avoid that?
======================
3Ah Makita BL1830 :
10 x Sony US18650 V (LiMn 1600 mAh, 7.5A continue ; 15 Amp burst, 18-30 mOhms DC)
Original Makita spec for the pack:https://www.elektro-online.de/img/shop/ ... bl1830.pdf

4Ah Makita BL1840 :
10 x Sony US18650 VTC4 (LiMn 2100 mAh, 30A continuous; 100A very short burst ; 12 mOhms AC)
original specs:https://www.powerstream.com/p/us18650vtc4.pdf

glue
https://www.aliexpress.com/item/Bicycle-Repair-Tool-Bike-Tire-Repair-Glue-Bicycle-Inner-Tube-Puncture-Repair-Cement-Rubber-Cold-Patch/32956475304.html?spm=2114.search0104.3.71.46717bfarz8rBG&ws_ab_test=searchweb0_0,searchweb201602_6_10065_10068_10130_10547_319_10059_10884_317_10548_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536,searchweb201603_53,ppcSwitch_0&algo_expid=75673b63-8a80-4298-bef0-01ff47ab6f7f-10&algo_pvid=75673b63-8a80-4298-bef0-01ff47ab6f7f&transAbTest=ae803_3

motor
https://www.elecycles.com/xiongda-2-speed-hub-motor-coversion-kit-36v-48v-250w-350w.html

 

[jonescg]

Even if you just nicked it and didn't go all the way through, it's not worth keeping the cells. The steel can is barely 0.2 mm thick, and it will rust through in no time.

 

[dogman dan]

I agree, might be ok to use them to run an led light or something. Almost one time use type of thing.

One or two in the pics are not so bad, but those ones cut a bit deeper are down to tinfoil thick. Don't want them to vent while discharging.

Wouldn't want them in use for years.

 

[want to build]

ok its nice to know. thx

how about if i put a bit of the glue on the sctraches wouldn't it prevent the rust?
that is for my mini batt

for my 2 large batt 4p13s 2 blocks i have a mix of cells intact and some scratched. they are show 4.10, 4.11, 4.12, 4,13, 4.14 once i have charged discharded recharged then let sit for 2 weeks. now i read that in a same paralle group it is better to have cells with the same voltage so i was thinking about making paralles groups of 4.10 only, others of 4,11 only but since the risk of rusting is something i didnot think about her is my new idea.

maybe i sould take care of having all the scratche one in the same battery and all the intact one in the other so that at least 1 have one pack that is long lasting. would it be ok to have in a same parale groupe 4,10 wit 4,14v since 0,04 volt is not so much of a big difference or is it a difference big enough that i sould avoid mixing the 4,10 with 4,13 for example.
i would like to be able to mix them because i would like to use the matching program https://secondlifestorage.com/repackr.php
to have groups of similar capacity.
tx

 

[BlueSwordM]

So, are you a Quebecker for some reason?

Because if you can speak French, you should post in French, and I'll try to translate it into more understandable English.

Hope this helps.

 

[hemo]

The discolouring/ change of wrap colour is between wrap and cell can, it is looks like electrolyte has seeped vented out, if they smell bin them. The rust on the neg end is indictive of venting/electrolyte seepage.

 

[want to build]

ok and is it ok to have 4,10 4,14 4,12 4,13 for example in a same parallel group or the difference of voltage is to high to place them in a same parallele group?

 

[Hillhater]

ok and is it ok to have 4,10 4,14 4,12 4,13 for example in a same parallel group or the difference of voltage is to high to place them in a same parallele group?

Others may not agree, but for me, those voltage differences (40 mv) are no issue for a parallel group.
Remember once assembled, the voltages will equalise on each parallel cell.

 

[billvon]

how about if i put a bit of the glue on the sctraches wouldn't it prevent the rust?

Nope. Those cans are already as thin as humanly possible; any deep scratches and they will be very close to failure/leaking.