Inverter Fault

Cadiman · 05-28-2023, 01:42 PM

Have a new Nitro 351 and am troubleshooting an inverter issue when attempting to run off battery.

Complaint: when not plugged into shore power and with battery monitor showing full charge, inverter control panel shows fault. All other 12v devices are working without issue.

I found the inverter and low 12v battery 🪫 was indicated on the control panel.

*Special thanks to FR for burying this useful feature behind panels and nearly out of reach in a crawl space.

I measured and found 2.6V at the 12v terminals in the inverter. I then went back to the batteries and confirmed that one battery has 13.1v and the second has 2.6, this battery is also the one connected to the “Inverter +12v” cable leading to the fuses.

My assessment of the situation is that there is a missing jumper between the +12v terminals of the two batteries themselves. Would like confirmation or even a similar picture to the one I have attached with battery covers removed.

Your input is welcome. Thanks.

TacomaJoe · 05-28-2023, 03:28 PM

Looks like you have a red wire from each battery to the positive bus. I'm not sure what's under the "BATTERY HOOKUP" cover, but could be a fuse. You don't need a jumper at the batteries if they tie together at that bus.

Cadiman · 05-28-2023, 06:28 PM

It looks like that, but it’s not a bus, it’s three breakers. The batteries are not connected electrically, except for the negative terminals as pictured.

AbdRahim · 05-28-2023, 07:32 PM

It would seem to me that the battery with 2.6 v is dead, and needs replacing.

TacomaJoe · 05-28-2023, 07:56 PM

I'm leaning towards your original assessment. If the Inverter Positive wire feeds through that middle (80A) circuit breaker on to the inverter, you are missing some sort of means to charge that battery. A missing jumper would do it.

dalford · 05-28-2023, 10:02 PM

Yea, I would replace the 2.6 volt battery as it is probably damaged. I would then get a red jumper and tie the + of each battery in parallel just like the -.

I would leave the rest of the wiring the same as each leg to the breakers have the heavy gauge wire needed.

Then both batteries will charge.

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