Tamiya made Neochamp Rechargeable Mini 4WD Ni-MH Battery 2pcs. (15420) Battery & Charger (AA) Mini 4WD Series
These rechargeable Ni-MH batteries are lightweight (19g each) and may be recharged approximately 2,000 times. Minimal self-discharging allows durable battery life. Battery life duration may change based on use conditions.