Originally Posted by Daryles
I installed 270AH lithium batteries (also left my FLA battery in place as a back up, have a 3 way switch installed). Installed a 2000w pure sine wave inverter. Tested TV, satellite, Nintendo etc. (Light loads, only a few amps).
Then tested furnace 11A. Passed. Then the big test, 1500W microwave. It pulled 164A and the OEM installed 4 gauge battery cable reached 134° in 5 minutes. I stopped the test.
If you plan on running high wattage appliances, you MUST install at least 0 gauge welders cables. Maybe 0/0 cables depending on your load. Welders cables are way more flexible to work with.
Do your homework on this. Safety first.
You also need to install a battery monitor system.
I have a Victron BMV-712. I can monitor my batteries from my phone.
If you start to power everything including high wattage appliances, you are better off switching to a 24 volt battery bank. There's less power loss, the wires don't have to be as big, etc.., but then you need to adapt the output from your battery bank to 12 volts so you can run lights, alarms, monitors, etc..
That wasn't an option for me do to the amount of rewiring required and how difficult it would be.