In order to prolong the life of your Casio NP-40 replacement battery please read the following:

Your Casio NP-40 battery is charged during production in order to test it. Your Casio NP-40 rechargeable battery will discharge between the end of the production and the moment you receive it. That is why your Casio NP-40 battery will have to be charged before you use it. You can use your existing charger or an external charger this will optimize charging of your Casio NP-40 battery and prolong the life of your camera power supply.

Your Casio NP-40 rechargeable battery discharges slowly and progressively when not in use. The self discharge rate is about 1% of the battery's capacity per day at room temperature. The higher the temperature, the faster your NP-40 battery will discharge. If you intend to leave your Casio NP-40 battery for a prolonged period without use then a service charge is recommended from time to time, taking in to account the self discharge rate and time between using your Casio NP-40 battery.

Rather than supplying original Casio NP-40 batteries, we supply replacement NP-40 batteries made by Uniross and Hahnel. Our NP-40 batteries have a two year warranty, represent excellent value and meet or exceed the original specifications. We also offer free delivery on all our products including the NP-40 battery.