EB70S vs AC50B output

Curious. I am experimenting with running a small Arctic King chest freezer using an EB70 and an AC50B with a Baldar 125w portable solar panel providing input. I am not running them co-currently. I am running in pass through mode.

Day one I ran the freezer with the AC50B. When the compressor cycled on, it pulled 87 watts from the AC50B.

Today I am running the freezer with an EB70S. When the compressor cycles on it is pulling 47 watts. This is a 40 watt difference. Everything is exactly the same as yesterday except for the Bluetti source>

can anyone explain this?