To keep it clear and simple,
I received my charger today, and attempted to charge my battery for the first time.
I had presumed that I should plug the bms into the battery before connecting the power charger to have a load for the charger and perhaps prevent a spark.
But, that didn’t happen.
I plugged the bms balance leads into the pack, and then the main negative in preparation to charge. I got smoke out of the first resistor on the bms within the first few seconds before I had even attached the charger.
I was thinking that if the bms shorted the positives and main negative of the pack, why would it only destroy one balance resistor? Maybe an inrush of current to balance only the first cell?
And yeah yeah I probably made some dumbass mistake but I have never seen anything mentioned regarding importance in order of connection to your battery for external bms, and this can help others not make the same mistake.
(I can elaborate with more pictures)
I’m very noob to this but one thing every one told me is that you should always insulate the cable you’re not working on.
At first glance I think your diagram is ok. But I’d let the gurus double check it
From what I’ve now seen and heard I simply should have connected the pack negative first
Good news is I think I disconnected quick enough for me to only need to replace a 5¢ resistor
Had to replace 3 resistors, and I finally got my multimeter and found out that I… had wired my battery in reverse
My ‘#1’ pin was testing at 46.2, not the 3.3v like it should.
Which is wierd, because I double checked that my cells series started from the negative of the pack, and I numbered them as I assembled them… nevertheless I then realized that it was reverse the whole way through the pack (#14 pin testing at 3.3v). So, that was also probably a reason why my charger wouldn’t work lol. I have to make an adapter now to flip all the pins order