Panasonic-Sanyo has been a household name in consumer electronics for several decades, always at the forefront in pioneering new rechargeable battery technologies. Their Eneloop series of NiMH batteries is engineered to provide an extremely low self-discharge rate, resulting in retention of up to 85% of their charge when stored for a year and as much as 70% after 3 years.
The branding on Eneloop batteries has changed from Sanyo to Panasonic
They're available in high-capacity versions and extended life versions, with the most recent generation tested to withstand up to 1800 recharging cycles. All Eneloop batteries are pre-charged using solar power, making them an environmentally sound and economical replacement for disposable alkaline batteries.