Help…..Frustrated Beyond Belief

So we have a Snowmaster travel fridge & it’s a spiffy little thing. Run it off a EcoFlow solar generator/battery that’s charged by a 12v outlet 

Today we stopped around 5pm (in eagle pass Texas) for dinner and the fridge was dead/battery dead and could not get it to run or charge no matter what I did. Could not find a fuse so I said to hell with it 

Got to Del Rio tried the fridge again and it powered up, the battery started to charge but then shuts off

Question am I sucking to much power thru the 12v outlet, or is something else at play here

I tried charging at 8 amps, then 6 & finely 4 amps with nothing different