As long as your bms is reading true there is no escaping opening the pack. Like a bandaid just do it. Think of it like opening a present, but instead of a treat is has a bunch of work inside.
Even if it is just super super unmatched cells it needs to be addressed. If it’s still marginal or your bench conditions mask it partially - best case the cell not connecting consistently will get amps dumped or pumped at a higher rate than the others and see heating the others don’t and get cooked faster and possibly die prematurely.
Nothing looks like a bad weld that i am aware of that isn’t one. If it did it once it will do it again but maybe when you’re out on a ride or charging while cooking dinner so something then
Im dramatic but seriously nothing else does that if the bms reading is good. Sorry @hatman
@Pecos I’ll take a vid tomorrow . I’m not that worried about it blowing up as it’s lifo-po4. The cells are mounted to a pcb so it’ll be a nightmare to take to pieces. Tbf I haven’t ridden the board yet so I’ll see how it is in the wild .
Thanks for the thorough explanation, I was assuming that was the case but you never know =D Im severely limited in top speed in my country so I was just wondering if there was a point to limit the voltage availeble.
Dismantled the battery . Re-did all the connections and even soldered the nickel onto the pcb and the same thing is happening .
Another vid showing the first few minutes of charge
That looks ok, charge and balance it then watch the discharge. Once it’s top balanced discharge it and watch it for the bottom of the soc and see what it does at the low end then watch the change cycle. 25a charge is pretty good - what charger do you use?
When it gets past 42v the cells seem to go out of whack and the charger just stops due to cell
Over voltage . I’ll take it for a spin tomoz though and see how it gets on.
The charger is from Ali express .
I feel like a beginner coming back to esk8 after 2ish years. A lot has changed but not so much at the same time.
What’s got me baffled is the choice of wheels and tires available. I’m swimming in options and don’t even have a clue what to get.
Mad v2s? Cloudwheel rovers? Etc etc
What’s the stickiest skate wheel of choice?
Last time I was around the ice blue torque board wheels had just came out.
I wonder if it’s just too far out of balance to balance fsr. Seems like a .1v should be totally within any balance bms’s ability to work out though. Does it get way off on the top of the charge and do you have a smaller charger (lower amperage trickle charger) that you can use to balance the pack? It may be that the big boi you have is just hitting the cutoff voltage too fast to allow the bms to do its work. If the pack was at 95%soc and was off by .1v it could take most of a day to balance automatically if you have some big p-groups.
use another connector plugged into the xt90s to sink the heat and keep everything straight if it does get a smidge too hot -
use a chisel tip not a pencil tip and let it get hot
pretinn both sides but not gobs of solder, just just enough to wet it and no more.
Have both the wire and the connector held in a vice or helping hands type thing -
use lots of solder paste flux -
use leaded solder, anything from home depo or Lowes is gonna suck and basically ruin your joints, it’s seriously trash it is from harrus
Don’t breathe the smoke, it’s not the lead as much as it is the flux and all the goodness.
When placing the iron, add a little solder to help it transfer the heat, get it hot and add any more solder to make it fully wet out and saturate it, then remove the heat. This should take a second and not much more. If it’s taking longer your iron is too small/weak/ or the recovery time is too long and insufficient
Once you get it, you get it so don’t give up yet - good luck
