EB70 not lasting long!

I have fully charged EB70, i plug a cooler box in which is 55w around 10:30pm come 6am when go to it the bluetti is flat, this dont sound right to me, how many hours should i get out of fully charged EB70?

Hi @Paul1 , sorry for inconvenience.
Have you tried to calibrate the machine?
First discharge the machine to 0%, then charge it to 100% with the AC port. During this time it needs to be charged continuously, not disconnected, and not with a loaded device.
We suggest you try this first and then see if the EB70 still has this problem.
Thank you for your cooperation.

It has been fully charged from flat twice now, plugged the cooler in to the eb70 at 10pm and went to it at 6am and flat, i thought it should last longer than 8 hours