[. . . ] The EN-EL1 is a rechargeable battery for use exclusively with Nikon digital cameras. [. . . ] You may notice that the battery is hot directly after use or recharging; this does not indicate a malfunction. â· Even when fully charged, the battery will discharge more rapidly in cold conditions. It is recommended that you keep a fully-charged, spare battery on hand. â· A marked drop in the time a fully-charged battery retains its charge indicates that the battery needs to be replaced. Should the battery terminals become dirty, wipe them off with a clean, dry cloth before use. Improvements to this product may result in unannounced changes to specifications and external appearance. After removing the battery from the camera for storage or transportation, attach the terminal cover included with the EN-EL1. â· See the documentation provided with the battery charger for information on recharging the product, as well as for further cautions and warnings that must be observed when recharging. [. . . ] When recharging, the ambient temperature should be in the vicinity of 5Â35ºC (41Â95ºF). [. . . ]