I was pretty disappointed with the RYOBI 1800W Powerstation. It didn't come with MPPT Solar charging or even Pass-Thru charging. I was curious if this was a limitation of the 40V battery or just the Power Station. After some quick tests, I determined you could charge and use the battery at the same time! So I designed and 3D printed two adapters. One that attaches to the 40V Charger, and the other that attaches to the 40V battery. Once you have these piece, you can combine them with a MPPT Solar Controller, a Solar Panel, and an Ammo box to build a simple Powerstation.
You can go to https://www.prusaprinters.org/prints/61098-ryobi-40v-pass-thru-charging-adapters to get a list of the parts I used. I no longer put them on Thingiverse since they started editing my links to make money off of them