12 Volt PowerWheels Battery/ Charger Combo - Auth Dlr - $64.50
Power Wheels powerwheels battery for car - $10.00
SILVERADO POWERWHEELS - $45.00
2 New Red PowerWheel Batteries - Auth. PowerWheels Svc - $55.00
EXCELLENT CONDITION POWERWHEELS BY FISHER PRICE - $75.00
Mach 5 Speed Racer Powerwheels Ride On Backyard Toy WOW - $39.99
Check the input voltage of your battery charger. Most of the modern ones will work happily with any voltage between 100 and 250. In which case you will be OK, although you will of course need an adapter for the plug. Otherwise, by far the cheapest so...
go to www.craigslist.com and put in your state that's about the best I can tell you
You can just stack them up, perhaps in a plastic tube, positive to negative, I have a small LED flashlight in front of me that has three button cells stacked in this manner, held in contact by a spring