battery pack problem?
- Thread starter crf150rb
- Start date
larsb
1 MW
There’s no starting procedure.. flip the switch and it’s on. Only way of helping you is if you describe your problems better.
larsb said:
Ok I am using a 14s 58.8v pack measuring 55v when disconnected from the esc but when connected it reads anywhere from 14-30v with e lock on and off. The 5v rail on the esc measures 5v for a second and than drops to .5 volts.
I got the thing to turn on once and was able to ride it but anything above 1/4 throttle the bike cut out and would not turn back on. I can send screenshots of the software if needed. Thanks
that means your battery pack's bms is shutting off it's output because of an internal problem of the battery, probably cells that are too low. (could be that the controller is a dead short inside, blown up, and the battery is shutting off it's output due to overcurrent...but that's not nearly as likely).crf150rb said:
the 55v may be "leakage" voltage, if that pack is supposed to be fully charged, because it should read 58v+ if it's full. that means that the bms has shut off, but with no load on the output (nothing connected to it) it could read any voltage at all, from zero to whatever the battery inside actually is at, prior to the bms.
since troubleshooting this is not part of this thread's purpose, i can get your posts about this moved to your own thread specifically for this, over in the battery technology section.
so, the first thing to try is simply fully charging the battery. leave it on the charger at least overnight. it's probably unbalanced, so some cells are lower than others, below the lvc cutoff point for the bms.
if you've already done that, you may need to leave it on there for several days, if it's badly unbalanced, for the bms to rebalance it.
if it doesn't have a balancing bms, it will never fix itself, and must be opened up and manually balanced by either draining the high cells or charging up the low ones, individually.
if you prefer, you can open the pack, and measure the voltage on each cell group, at the bms balance wires starting at the most negative one and working your way to the most positive. for this you put the voltmeter black lead on the thickest main negative wire from the cells. the red wire goes to the first balance wire. write taht voltage down as cell #1. move the black lead to where the red lead is, then move the red lead "up" one balance wire. write taht voltage down as cell #2. repeat until you've measured from the last balance lead to the thickest main positive wire from the cells. post that list here.
if you've already done that, you may need to leave it on there for several days, if it's badly unbalanced, for the bms to rebalance it.
if it doesn't have a balancing bms, it will never fix itself, and must be opened up and manually balanced by either draining the high cells or charging up the low ones, individually.
if you prefer, you can open the pack, and measure the voltage on each cell group, at the bms balance wires starting at the most negative one and working your way to the most positive. for this you put the voltmeter black lead on the thickest main negative wire from the cells. the red wire goes to the first balance wire. write taht voltage down as cell #1. move the black lead to where the red lead is, then move the red lead "up" one balance wire. write taht voltage down as cell #2. repeat until you've measured from the last balance lead to the thickest main positive wire from the cells. post that list here.
