The battery builders club

[ZachTetra]

30 fucked up 35e cells?

[MysticalDork]

Hell yeah. Or 60 including all the others. Pack 'em in a flat rate box and shoot them my way!

My current brick is 84 assorted used laptop cells, and I want at least one or two more bricks’ worth.

[ZachTetra]

If you want it I’m going through the proper channels for it, I’m not flat rating these… But I can get you a cost if you really want

[fessyfoo]

@ZachTetra

I got 30 of the sketchiest chilling

what constitutes “sketchiest” ?

[ZachTetra]

All the shrink wrap is missing, the welds disintegrate, most of the nickel shows signs of shorting multiple times, there’s solder inside some positive terminals, it’s made with fucking super glue

[Flasher]

Battery not charging

When you say discharge all to equal. How would I do so? Hook up some sort of load to each grouping? (run a load that requires 3.6volts and run positive to where i was testing each pack and ground to ground?) Supervised charged seems a little easier and less time consuming. but how do i supervise charge just that one grouping? Same way, just positive to the positive lead and ground to main ground… but what do i use to charge it? thanks!!

These are the kind of questions for battery builders with more experience than I

I’d say use a hobby charger on the pgroup so you can precisely adjust the wanted voltage. I was recently told you could use the balance leads to do this without dismantling the entire pack like I did

Edit: found it. @iamasalmon

@iamasalmon

no need to remove from the pack.
you can bleed and charge 2-3amps safely through the balance leads. I do this all the time

[danp]

Thanks. I will hold out for some more specific direction from the group here. ie… what specific hobby charger and how to precisely hook it up. But very good direction @flasher thanks!

[fessyfoo]

@ZachTetra

there’s solder inside some positive terminals

[ZachTetra]

Yeah it’s good stuff

[fessyfoo]

I’m interested in another take apart. something that’s spotwelded. I’d like another run at getting that more correct.

but solder inside the postitive terminals sounds scary.

[ZachTetra]

I mean it’s in the fold of the negative terminal on one of the cells are the positive end, I cracked the part off that was in danger of shorting so I think they are stable

I have 30 of those cells, 18 in my first welded battery which has solder over the nickel and a copper bar, and like 20 garbage loose cells

[danp]

If i was to take this 10s3p down to a 10s2p what would be the steps necessary?

[iamasalmon]

step 1 : find your fire extinguisher and keep it close…

You pretty much have to tear the pack down to bare cells and rebuild. often not worth it. sorry, there are far too many steps for one post, should be a topic in itself

[ZachTetra]

One at a time cut all the wires
Separate the 2 halves of the battery
Snip the center series connection
Peel the fishpaper and tape off
Pull the parallel groups apart
Snip a the series connections
Pull the nickel off each parallel group
Grind all the nickel off the cells
Re wrap all the damaged cells
Add insulator rings
Check the clock and see that took a long ass time

Just buy a new battery or buy fresh cells and make one yourself

[danp]

I guess technically, i can just get an already spot-welded group of 6 batteries for (group 1,2) and just replace it and it will be all good, yeah?

[fessyfoo]

I don’t understand what you’re thinking. can you rephrase?

[iamasalmon]

@ZachTetra

One at a time cut all the wires
Separate the 2 halves of the battery
Snip the center series connection
Peel the fishpaper and tape off
Pull the parallel groups apart
Snip a the series connections
Pull the nickel off each parallel group
Grind all the nickel off the cells
Re wrap all the damaged cells
Add insulator rings
Check the clock and see that took a long ass time

this is only half the work. Then you need to build a battery

[ZachTetra]

By adding new cells to an old pack you will wear down the remaining cells faster

[ZachTetra]

Lol yeah, that’s just the salvage

[danp]

I thought of another idea…let me know if it will work… as the intent is to take group #2 from 3.5 volts back up to 4.1. What if i snipped all of the BMS wires except #2. Thus the BMS would only see #2 connected. Would the BMS then only charge #2 up to 4.1v ?