question

@Alpinebound, your MPPT will throttle its throughput when it's overheating, so I think that a loose or poor connection is most likely the culprit here. If the positive battery terminal was a little loose there's a good chance that something else is too... whether it's a loose or poor crimp somewhere, some other loose connection, poor off-brand fuseholders, fuses, or circuit breakers, improperly crimped or connected MC4 connections, orrrrrr undersized/wrong type wire from the MPPT to the batteries, I can pretty much guarantee that it's something in there that's causing your problem.

The MPPT does indeed have an internal fuse, but they don't half-blow... if it blew, the MPPT would be fully bricked.

I would start by checking your voltages at the MPPT terminals... check for the appropriate voltages at the PV side, then the battery side, then work your way up every fuse and every connection. It's not impossible that it's the controller that's gone bad, but 95% of the reported problems with controllers that I deal with are actually caused by the connecting components, not the controllers themselves. One bad MC4 connection on your PV string, for instance, can cause exactly this type of behavior because it stays relatively cool until the controller puts a load on it, then it starts heating up as the controller draws the current through it, then the controller sees the increased resistance from the overheating connector and throttles itself, and then the process starts all over again. I've also seen the same thing happen when people use the Amazon knockoffs of Blue Sea circuit breakers... I know they look the same and have the same rating printed on them, but there's a big difference in component quality, and I've seen a knockoff series 285 get so hot it would literally burn you to touch it... and it made the MPPT it was connected to behave in the same way you're describing. I've also seen a single incomplete crimp do the same thing... again, cheap Amazon lugs can appear to be crimped but pull off with the slightest effort, and any crimp that loose is just sitting there generating heat.

Hate to say it, but start at the controller with your multimeter and temperature sensor (an infrared camera or a handheld IR temp sensor work great) and work your way all the way up your PV string, then turn around and work all the way back to your batteries... it can be a long, painful process but I virtually guarantee you'll find a bad connector or a failing component somewhere along the line.

Good luck!

Thanks for all the input kind of embarrassing but I found out everything is actually working the way it's supposed to I've got a small cell balancer monitor that tells me the state of charge of each cell and the whole battery Bank as a whole and the presets for the charge controller we're set for life were going into float and on my other meter I was seeing the battery state of charge only getting up to 92% and I guess those are the safe working parameters that the mppt victron engineer's set so I'll just let it be in short I wasn't drawing any power off the battery and the charge controller wasn't float as soon as I starteddischarging a significant amp load the charge controller kicked in And drew amps off the panels