BG797483753 Gens Ace makes a 1300mah 3S that fits perfectly

BG797483753 You can buy parts through AliExpress — several sellers have both original and hop up parts. But the cars are broadly compatible with 1:10 scale parts and fasteners (12mm wheel hexes, 4mm axles). When I replace screws, I just pull 2.5mm or 3mm screws from my spare parts bin.

BG797483753 Gens Ace makes a 1300mah drone battery that fits like it was made for it. Just measure the battery it comes with, and buy one that fits in those dimensions.