PowerOne Accu Plus rechargeable hearing aid batteries and portable chargers. Accu batteries are the only quality made rechargeable Nickel Metal Hydride (Ni-MH) batteries on the market. These batteries are designed to replace zinc air batteries. Must be used with a PowerOne Accu Plus charger, an exclusive PowerOne design. The Pen Charger charges one NiMH button battery from 2 AAA alkaline batteries. Charging time is around 5 hrs.The new portable Pocket Card-Charger, charges two batteries in around 2.5 hours. Complete instruction manuals accompany each charger. Batteries can be recharged more than 600 times. Join the green revolution and stop contaminating the environment. Replace your disposable batteries with rechargeable batteries.