This is 300mah ni-mh rechargeable 9v battery is low-self discharge 9v ni-mh batteries have become available in the last few years.
this 9v rechargeable battery “low-self discharge” label means these batteries will hold their charge for a year, unlike previous nimh batteries.
this makes these 9v batteries much more compelling because 9v batteries are often used in applications like fire alarms, where the battery must sit for year or more.
available in large qauntities