Hot Multiplus II 24-3000-70 shedding load?

DIY
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1

I had a 30 amp 120V service line from motorhome attached to service pedestal, while the 1800 watt air conditioner was running on a 100 degree afternoon. After an hour had passed, I noticed via my CCGI that the coach batteries (10kWh Lithium) were providing about 1000W of the load requirement, and the Multiplus was providing the balance of power while also trying to recharge batteries. I checked and found the Multiplus was quite warm to the touch, perhaps 100-120F.

I power-cycled the Multiplus and it began operating just as expected, with 120V pass-thru mode supplying all the 1800W air conditioner needs, while still recharging the now slightly depleted batteries. Temporary glitch?

However it soon went back into the mode of providing about 800W of the air conditioner needs, while the coach batteries were again discharging to provide the remaining needs. I opened the Victron equipment bay door, added a small fan, and reinitialized the Multiplus. It then ran flawlessly. through the remaining afternoon and evening. The Multiplus chassis was slightly cooler with the fan air blowing. Sadly I never took note of the TEMP LED warning light status on the Multiplus. System has bee trouble-free for over 5 years, but rarely used in very hot conditions.

I have the battery thermocouple installed, and that temperature showed 100+ F. I understand that the Multiplus will adjust charging rate based upon the measured battery temperature, but only slightly until 120F (50C).

Can anybody explain why the Multiplus began to load share with the coach battery?

Also, is there a good tutorial about checking and possible up-leveling the firmware?

2

Interesting, I have that same inverter but haven’t had it that hot yet. VRM history might yield a clue, maybe shore power voltage droop?

3

Possible. However it ran fine once the ambient air was circulated in the equipment bay.

4

Firmware updates should be approached with caution and only do this if needed for new features or if there are problems. Also, make sure to follow the process exactly. Some updates require you to save a copy of the settings file, update the firmware, update the settings file separately, then upload the updated settings file to the inverter.

If your CCGX is new enough you can update the firmware over the internet through VRM from a laptop/pc. You will need the VE Configure program.

If you can not use VRM as above due to an older CCGX then you will need a mk3 to USB interface. You can connect using the VictronConnect app on a Smartphone or a laptop/pc.