in most cases you need 1000w or so
It's not the running power, it is the compressor start power,
Just like A/C, only to a lessor amount
In the safari our residential fridge used about one amp at 120v when running
That measured at 9 amps at 12v
But the start up surge was over 900w
I installed the Tripplite PV1250, and it was flawless runs prefect