Just got myself 8 AAs (Rechargeable) from IKEA for my custom 9,6 V battery pack which I use for my Nikko Super Cruiser. A bit overkill when you count the capacity lol. :
Batteries & Power – Rent in NYC at The Imaging World Camera Rentals in Brooklyn
Nikko 6.0 V NiCd Battery 4 hour charger 1264 Slot In | #205379767
RECHARGEABLE BATTERY PACK 6.0v Power Zap Toys Twin Pack Charger Like Nikko Tyco $28.95 - PicClick