Jackery battery & electricity noise when recording guitar with pickup

I have Jackery battery (220V, 500W) and I want to record my guitar with pickup. When I turn on electricity on the battery, strange noise is being heard.
My pickup: Dean Markley Pro Mag Plus Acoustic Guitar Single Coil Pickup
At 10:00 I turn on the battery but electric cable of my computer is not yet plugged into the battery (some noise can already be heard!). At 00:32 I plug in electric cable of my computer into battery. The noise is overwhelming. Is it possible to resolve this?