If the cell’s fine, then there’s no reason to remove the nickel.
If the cell’s not fine, then you could remove the nickel and remove that cell.
Really no way to be sure if the cell’s fine without inspection, but I’ve done that exact same thing several times and it’s never hurt the cell. Up to you and your risk tolerance though. Simple test is smell. If you can smell electrolyte, it’s fucked.
thx, I don’t smell anything different. The voltage checks out. 
Be very careful with the welds on the positive side, if you set one right on the edge you can short out the cell. Don’t ask me how I know. 
Is this ok under load or is my battery trash?
10s4p VTC5A cells, vesc set to 80A max discharge
holy mother of sag.
80A per side or total?
Now you are making me doubt 
Motors are set to 55A per side, but I might have forgot to divide the battery amps 
Will check when I get back home
Even at 80a total, 20a is a lot to be asking from those cells.
Oh didn’t know that, I was looking at Mooche’s testing that was stating max 25A continuous discharge
VTC5As can handle a lot of current, even more than VTC6 cells. This looks pretty excessive though.
Is that bench load on that clip?
If so, than it’s quite a bit of sag.
If you draw 60A or something, 2V overall sag seems not too bad actually.
more like 3V
I’m worried about this one. I wonder how much of the isolator ring is left. I’d know by now if I hit that outer negative ring on top huh?
Oh no worries, if you killed it you would’ve known.
Depending on the load 3V is still ok for only 4p.
What’s the best way to run pack negative, positive wires? Yellow and blue would need extra protection cell side huh? Also I should have soldered the negative wire on the nickel before welding it to the cells (side note).
Looks right for an ~40-50A battery pull on that 10s4p VTC5A pack.
You can use the comparator here, but instead of picking two cells, only select the VTC5A cell and select 0.2A and 20A. It would show how much sag you can expect at 80A on a 4p pack. 4.0v to 3.6v or 0.40v per cell.
Having a metr log, or even a regular VESC log would help show voltage vs battery draw.
For example on a metr log:
So this battery is sagging 48.0v - 43.5v = 4.6v / 12s = 0.38v per cell at 143A. Dividing the amperage by the p group amount and use the comparison tool above will show how the pack is doing vs the cell’s expected performance. That would highlight an issue with the cells (age for example) or pack construction if it was say double what the cell was expected to be.
I think it all depends on how it lays out in the enclosure. I’d prefer the cyan approach (maybe flipped) if it wires up cleanly.
Most of the series connections are soldered after the nickel is welded, so the pos/neg should be fine too. I usually put something between the nickel and the fish paper (like an old PCB) to help insulate from the heat.
Thx, how much wire should I strip and soldered to the nickel. Does it matter?
Good idea
It’s under load full acceleration from standstill on a straight flat road (15/35 reduction with 6355 motors and TB110 wheels), no load there is almost no sag
@jaykup
Thanks a lot for those infos, I’ll plug in my laptop on my next tests to be able to log everything since I can’t plug in another UART device on my vesc
(As soon as I am able to reprogram my fsesc, I have some trouble with it since I reprogrammed it a few times…)
Cells are new, they were stored in 4p packs for a few months at storage voltage tho
Edit: is it ok to have as much voltage difference between series connections while under load? I didn’t really match impedance since they all came from the same batch and thought it wasn’t necessary
