These economical and eco-friendly Tenergy Centura Ni-MH AA batteries last for up to 2100 recharges, retaining 95% of total capacity after a year of daily use. Rechargeable batteries cost more upfront but provide 99% savings in the long run. NiMH cells remain suitable for emergency use, losing no more than 15% of charge in storage. Plus, these batteries are widely compatible with devices that normally use non-rechargeable alkaline batteries and don't have a memory effect.