What he said. I've had spotty performance from all kinds of smart battery chargers for tools, drones. Say they're full and they're not, or just won't charge. Put them on a real sine wave inverter and all was well.

 

I have 2 Milwaukee chargers in my truck so I ran 4ga welding wire, ground to battery and hot to #5 upfitter. It’s a 12ga 40 amp and works good for the 750 watt inverter. I have 2000 watt inverter with quick connects that I carry in my truck if I ever need it.
The factory one is useless, only charger I’ve had luck running on it is the paslode charger.