Ok please forgive my ignorance, my dad was part way through building this out for the RV when he passed away. Mom still wants to go camping, so I’m trying to finish Dad’s work. Coming in with lots of electrical knowledge, but no knowledge of inverters, big batteries, or generators.
2/0 10ft cables on the DC side, fused at 300amps, 6 gauge on the AC side with the stock RV 50amp panel. With the windows computer and the USB adapter I changed the settings to match the battery, set an input amp of 15.8. Generator app reported 1750-1800 watts of load.
Issue 1:
Inverter would reset the AC input [idling down the generator] when high AC loads cycled, which seemed strange? The AC didn’t stop functioning though, the load/output side was not interrupted.
The way I thought this worked the generator shouldn’t have even have known about the change in load? Is this expected behavior or indicating an issue?
Tried Eco throttle on and off, and two different power cords.
Issue 2:
At one point it was hot outside so we had the AC on for a few hours. The battery hit 47c which is apparently not good for it and then things behaved oddly till the inverter and battery cooled down. I’m considering using an old raspberry pi 3 and VenusOS to try and get some logging and hopefully feed battery info [temperature, etc] to the inverter, but maybe I’m making things complicated for no reason?
I believe this battery uses the JBD BMS. Ideally we could setup an easier cleaner interface for Mom’s phone too, but it has to work without a router.
Monitoring actually makes it less complicated. Information is helpful when diagnosing things. So add that.
Is everything programmed for the battery correctly there should be an mk3 to usb adapter around for that?
The bms will handle this and should cut off if there is an issue. But it may be wise to lower the charge rate a bit.
This is because the sine wave got a bit weird. The load may be a bit high. Try a lower input current. Something aroud the 1200 to 1300 mark.
We do have the USB adapter and I was able to set the inverter to charge for a LiFePO4 battery.
I’m fine to lower the input power, that’s fine, I thought the inverter kept the input and the load really cleanly separated, so the AC cycling shouldn’t have affected the generator side at all?
The generator side only got weird when the AC load got went from low to high, otherwise it was stable and seemed perfect.
Setting up the logging with the pi will definitely be happening, that can only be helpful.
Edit: So you would just ignore the battery temp and let it manage itself?
I meant to include that i am sorry to hear about your Dad. It creates a hole in lives takes some adjusting to get life balance ok again.
@Karl-Heinz brings up some good pointers. Location and cooling matters.
The battery getting hot could be actually just the bms getting hot. I am not familiar with the battery you are using but I see that more often than cells getting warm. But leaving it in an enclosed space wont help.
It’s a fifth wheel travel trailer, it’s mounted in the front compartment with the spare tire. No other electronics in the bay.
That compartment door was left open for cooling.
It was a hot day, in the '90s, and overnight the dog had managed to turn the electric heater on and we hadn’t noticed so the battery was dead flat in the morning, so it had charged from the generator for a while before we were running the AC.
All in all It may have been a one-off event that will never occur again, hard to say? I just don’t know how important it is that the inverter knows what temperature the battery is. Judging by your guys’s responses, that’s not a thing that’s usually worried about?
The body of the battery did not feel hot to the touch, so it very well may have just been the BMS. Just seems weird because at that point the battery wasn’t doing much, taking a low rate charge while the generator and the inverter and the AC were all running, we were only slightly power positive.