A:AnswerNot exactly sure what you’re asking. If you mean will it charge another 12v battery through the terminals on the back of the unit when plugged into your homes power then yes. It recognizes all attached batteries as one and charges them all.
A:AnswerYes but Duracell does not recommend it. Why they don't recommend it is in the FAQ's page.
https://www.duracellpower.com/products/1440-watt-power-station
A:AnswerSince I have not had an opportunity to use my generator, I do not know the answer. However, if I do have to charge the battery, I would check in with the local gas/repair station or a car dealer's shop.
A:AnswerYeah I'd say that is exactly what this is for. Especially if you have one of those 12V domestic fridges that run super efficiently and have a 100 Amp solar panel, or a bunch of solar panels on their own controller connected to the battery posts.