If the inverter efficiency is 80%, 3 1.25 /0.8=39 AH.

Ordinary battery cars are generally 20 AH, so they can be used for half an hour at most.

As the current is greater than the recommended current of 20 AH battery, it is estimated that it can only be used for 15~20 minutes.

At least 50AH or more batteries should be equipped.