Thor Forums

[robertj1961]

I wanted to see how the charging would work when temperatures were a little colder given Relion states you can do that down to -4.
Temperature was 25 degrees so was hoping would not be too much of a problem.
Wrong!
I decided to start the Onan generator instead of plug in to the 30 amp circuit.
Generator started a little slower than normal but didn't seem to mind the cold temperature. It was running normally and as usual, after about 30 seconds, heard the "click" sound that is the inverter/charger energizing. Mastervolt display showed "bulk charging" which is normal with the batteries being at around 40% SOC. Generator ran normally for about 1 minute and then abruptly shut down and all DC power was lost to the van.

I checked the circuit breaker on the generator that had tripped and reset it but that just protects the generator and still no DC power in the van. Checked all "known" circuit breakers and nothing had tripped. There is a 50 amp breaker underneath the van near the low point drains that was fine and had not tripped. Not sure what the 50 amp breaker is for? I decided to plug the van in to my 30 amp power source to see if that would reset or work.
It did not. Still no DC power with no lights or anything working that was DC powered. When I plugged in however, the Mastervolt display came on and said the voltage was 5.6 volts? That was also confirmed on the BM Pro display.
Decided to call Thor who tried to be helpful but honestly had no idea what could cause this. Tech guy said the suspected he 250 amp fuse had blown that is not resettable but has to be replaced. That fuse is located near the 50 amp fuse.
I was hoping the Relion BMS system was the problem and would reset correcting the problem as temperatures warmed up. I decided just to unplug from the 30 amp source and deal with it later. I re-checked the van about two hours later and everything was back to normal showing 12 volts and working normally again.

Any ideas on this appreciated? I suspect that supplying the charging source (generator) during cold weather caused a "shutdown" of the Relion BMS for some reason. The batteries are "supposed" to heat up when a power source is supplied and then start charging when the temperature is high enough but obviously this did not happen.

No idea why the Mastervolt would show 5.2 volts when shore power was supplied?

Was wondering if anyone has had similar problems trying to charge the Relion batteries when temperatures are cold?

I suspect Thor has not "thought this thru" with regard to how the Relion System works with regard to the inverter/charger supplying the power to heat the batteries prior to them accepting the charge?

I realize that 95% or the Tellaro's out there have the underhood generator (UHG) with the Relion setup but mine is somewhat unique with the Onan 2800i "IN PLACE OF" the UHG. It is possible this is a problem unique to my setup and thought I would mention that.

For now plan not to charge in cold weather until I get this sorted out. Luckily I am in North Carolina where cold weather is not as much of an issue as many other areas.