Update:
I tried to retest battery A with the 40amp load again, but things went south again. I think it's me, though, not the battery.
In order to decrease variables, I didn't use my funky old battery cables. Instead, I stripped the ends of a 12" piece of extension cord and used that.
I watch the temperature of the battery terminals like a hawk, and they were fine. Started at 77°, maxed out at 82°.
But, 5 minutes into the test, the extension cord housing at the inverter and started to smoke. I shut everything down of course, and then checked the temperature of the cord. 117° then, that was maybe 15 seconds after I shut stuff down. I'm guessing it was more like 130-140° when running.
Why did this happen? I was running a space heater on low, I think it is 600 watts, through an inverter. I run that heater on high, 1500 watts, with the same kind of extension cord and shore power, no problem. I realize the inverter increases the draw, but not that much, right? Was it the shortness of the cord? I know a long cord is more resistance, but I suppose it is also more heat dissipation?
A second puzzle: When recharging with the meanwell at 14.37v, amps went down normally to about 1, and then started to go up. 2 hours past the 1 amp mark, it was at 1.75a. I was tired and hot and my timer is broken, so I shut down the meanwell and came in to ask you guys. Or I can just see how it is tomorrow.
PS: Standard orange outdoor extension cord. I think those are 12ga?
