Panasonic Eneloop AA 2100 Cycle Ni-MH Pre-Charged Rechargeable Batteries, 4 Pack $8.92 @ Amazon or $8.47 w/ S&S

BK-3MCCA4BA Recharge up to 2100 times Maintain up to 70% of their charge after 10 years (when not it use) 2000mAh type, 1900mAh min, Ni-MH pre-charged rechargeable battery Pre-Charged at the factory using solar power and ready to use No memory effect - batteries can be recharged when fully, or partially discharged https://smile.amazon.com/dp/B00JHKSN76