I'd suggest that a 900 watt microwave may draw about 100 amps. I know my 1570 watt Dometic draws 185 amps.
I was able to successfully operate the Dometic microwave on 3 Marine jars for more than a few minutes. I have two banks--and one was 3, the other was 4 batteries. Switching allowed me to do either/or/both/off.
100 amps is what I was assuming from my 900w microwave.
Question: Are you saying you were able to run your 1570w microwave for several minutes with 3 batteries? If so, then it seems like I should not have a problem running my 900w microwave for even longer.
I guess I'll find out and report back.
-Chris
