Rechargeable batteries, is charging limited number of rechargeable batteries, use with the charger. Usually sold on the market, 5, 7 but there are no. 1. Rechargeable batteries are the benefits of economy, environmental protection, power, suitable for high power, long time use of electrical appliances (such as the walkman, electric toys, etc.). Rechargeable battery voltage is lower than the same type of disposable batteries, AA battery charge (5) is 1.2 v, 9 v rechargeable battery is actually 8.4 volts. Now can generally charge number around 1000. In February by 2012 only five kinds: nickel cadmium, nickel metal hydride, lithium ion, lead, iron, lithium storage.