How do you measure cells in LiFePo4 Pack

[teklektik]

i think he decided the wires overheated because the insulation was melted on the wires during the assembly ...

Gotcha. I missed that (speed reading again...). Thanks!

 

[dnmun]

nope, he did not think that, he thinks it melted the insulation because he had too much current. but since it is melted right where the wires are soldered to the BMS i am fairly sure it happened at assembly.

 

[Hiconic]

i think he decided the wires overheated because the insulation was melted on the wires during the assembly when they soldered the battery and power leads to the BMS. i don't think his BMS can make enuff power to overheat the wires.

Thanks for all the latest advice guys there's a lot of sifting and deciphering I need to do for my limited knowledge to comprehend.

One thing to clear up is that the battery pack wires (as far as I knew before opening) were intact. The wires coming from the BMS to the connector (power) melted back from the connector, all the way back to the pack. One wire melted and stopped at the connection of the first/last? cell. The other melted to the corner of the pack about 3" back from the negative terminal on the PCB (BMS) and as I said the wire just turned to what looked like solder, leaving half melted, empty insulation. The wire to the negative terminal on the PCB (BMS) can still be seen(3"remains) in the original cloth type insulation from the PCB and the negative terminal seems to have escaped the impact of the melt.

From looking at the system before disassembling it, it seems to me that the spike took out the breaker and on/off switch as the positive wire from the on/off to the breaker seems to have been under the most stress at the time, but the most damage heat wise is the battery lead /connector. The wires in the connector itself are still intact but as you can see in the image that the rest of the lead is fried! Seems to me that on looking at this, with my limited knowledge, I would say that the BMS/battery contributed somehow in not dealing with the spike in amps. Not sure if this is a requirement the BMS is suppose to handle, but I guess the controller also should have cut the current as well?

Regards
hiconic

 

[999zip999]

I wouldn't put all that shit on my bike. Time to K.I.S.S. Just a precharge resistor and loose some things.

 

[dnmun]

ok, i was looking at something else. those wires have the spade clips on them too and that makes a lotta heat too so maybe the wires got hot from the clips making poor contact also. do you have wire stripper that has the holes in it so you can compare to the size of wire in that cable? the holes have labels like 10G, 12G, 14G, 18G so see if you can tell which hole matches the wire. maybe 20G?