In our case the inverter was beeping, shutting down and showing an error code. Investigation on the error code showed we had insufficient dc voltage.
The inverter shut downs occured when a mixer was turned on. As a previous poster mentioned, motors have momentary startup current that is multiples of the running current.
I think the only solutions are a large battary bank that can handle a high surge current and maintain proper voltage, or an alternator that has good output to keep the battary(s) charged.
We added the high output alternator and that solved our problem.
Our truck runs all the time when we're producing product (Cummins soft serve truck) The stock alternator just couldn't keep up with the demands of the cooling fans 30+amps dc, inverter, pto clutch etc.
The stock alternators in most vehicles don't have much output at idle. If you have a 1500watt or better inverter you're drawing over 100 amps dc. Someone could get by if they're running a route and on the move a lot, but if you're stationary at idle drawing 100+ dc amps you're going to need a decent battary bank.
An alternator upgrade was a good solution for us.
A side note, if a high output alternator is added heavier or additional grounding wires and hotlines from the alt output should be added.