How can I salvage/reuse the batteries?

So the tablet is trashed. Screen busted like it was thrown against a brick wall and then bent over a barrel busted.

I actually got it to charge and come on.

Back cover off etc, bumped it and the coverless tablet hit the hardwood floor right over the charger plug in and busted that too.

But I notice the two batteries are pretty high capacity and have regular wires coming from them into a plug that plugs into the board.

These batteries would make excellent energy storage for anything from solar recharged LED lights to portable power for other devices and items.

I also have several solar panels ranging from 4” X 4" up to 3ft X 3ft.

The wiring harness/plug coming from the batteries has two red wires, two black, and one white in the center.

I would obviously clip them at the plug that plugs into the board. I would also clip the wires coming from the charger cord at the DC pin plug side, but then..... How do I wire those batteries/wires to accept the charge?

I imagine however I'd do that, is also how I should wire it to power up other items.

Lastly, once I've gotten that part done, can I just connect a solar panel to the wires or will the varying solar charge cause damage?