High Current Wiring Get hot!!

[JohnnieB]

Originally Posted by Tacodipstick

I have a similar problem; however, only my positive terminal cable that connects to the solenoid contact gets hot. The other 6 AWG cables do not heat up at all, including the return cable. Either as a result of something downstream causing the hot cable or possibly as the source of the issue, as I am here to ask, the positive battery terminal has heated up enough to melt/deform the post and surrounding plastic. Also, the solenoid contact has a plastic piece around the inner nut that has begun to melt as well. Battery-to-battery connections are 4 AWG. Any suggestions? As another possible source of information, a volt-meter readout is available on the dash. When the cart runs, the voltage drops from, say, 37.5V down to 34.5V, sometimes slightly lower when going up hills (quite slowly I might add). I just thought of this and have not confirmed the wiring configuration of the volt-meter. Finally, the cable in question has a discolored and hard/cracked insulator near (3-4 inches) the positive battery terminal.

In a nutshell, any cable that gets hot, needs to be replaced and any connection that gets hot needs to be fixed.

All high current cables (13 or 14 of them in a Series drive and 10 in a SepEx drive) should be 4Ga or thicker for use with controllers up to 400A and 2Ga or thicker for controllers above 400A.

The voltage of a lead-acid battery drops when amps are being drawn from it.
With a 369V battery pack, the batteries, in and of themselves, will typically drop about 1V per 100A of current draw. When you add in the resistance of the high current cables, the voltage drop per 100A is greater.

You dash mounted battery voltmeter is going to bounce around quite a bit because the amps being drawn vary considerably during operation. What you are seeing is normal.

Try not to drop the voltage below 31.5V during normal operation and don't drop it below 27.0V since that is were irreversible physical damage to the battery plates starts occurring.

[mutant]

sounds like time to replace all cables-i have 2 gauge or better and i get no heat problems going up my hill that is so steep i get 39.8mph on the downhill i made my own cables-but my buddy got scotty`s and they are fantastic! good luck!