Aims inverter problem

Okay so I have an aims 2000 w pure sine wave inverter. I have it wired to the positive side and negative side of my battery bank which is wired in parallel. As soon as it drops below 12.8 volts in turns off. I sent it back to aims and they rebuilt it but it’s doing the same thing. I use one electrical item at a time on it and all my electrical accessories operate well below 2000 w. I don’t understand why it’s doing this. I tested it with a multi meter and it has multiple battery monitors installed that all read the same thing. All my 12 volt accessories work great. No issues there. Any ideas?

Greetings & Welcome!

It doesn’t sound like the inverter is your problem. Most batteries are designed for slow but steady discharges, and a sudden high draw will simply overwhelm them, dropping the available current to below the 12.8v threshold.

A 2,000 watt inverter is a ~200 amp draw on your battery bank. In comparison, most starters only draw 60-150 amps, but the chemistry of starter batteries is different. They are designed for that short but large burst of power. Deep cycle batteries are not.

Tell us the specs on your battery bank, and we’ll go from there.


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12.8 volts is a fully-charged battery at rest - an inverter shouldn’t shut down unless it goes below 11 volts or so. Are you sure the voltage isn’t dropping below 11 volts or so when you put a big load on it (measured at the inverter, not the battery)? It will drop quite low if the wires leading to the inverter are too small. Also, is your battery bank capable of delivering 200 amps? Check the battery specs. Below is a wire gauge chart. 200 amps requires some very thick wire, and short runs of wire.