I already have a collection of Dewalt cordless power tool batteries so this is the solution I decided to go with. Super simple and inexpensive if you already have some power tool batteries laying around.

You just need to wire this: Dewalt battery adapter

To this: Wire harness connector

And mount the battery adapter to the battery storage area of the vehicle. The existing power wheels battery plug will fit right in and you won’t have to modify the current wiring for the vehicle at all. The new harness also has an inline fuse so you won’t have to worry about anything overheating or burning out👍🏻

If that doesn’t work, you could buy two aftermarket 12v batteries and daisy chain them together, which you could then wire to the same wiring harness/plug that I mentioned before.