Cordless phones use many different types of rechargeable batteries, depending on the manufacturer and phone model. Phones are shipped with the battery charge nearly depleted so it's important to fully charge the battery, usually overnight, before you use the phone. It may take several charge cycles to maximise your battery's charge. Once charged, the battery should last anywhere from one to three years based on your usage and treatment of the battery.
Charging a New Battery
Cordless phones are shipped with the battery nearly depleted. You may still be able to turn the phone on with the small, remaining charge. However, it is important to fully charge the battery before using it. Plug the AC adaptor for the charger into the wall and then insert the phone into the charger, making sure it is fully seated in the cradle. Depending on your model, you may see a charging symbol or light appear on the handset or phone base. Let the phone charge overnight before using.
Battery Talk Time
How long you can use your phone on a fully charged battery varies. It depends on the age of the battery, the model and features of the phone and the power demands of the equipment. You can find out how long your phone battery should last from information included with your phone or through a buyer's guide such as CNET or "Consumer Reports." Fully charged batteries typically are good for eight to 12 hours, but it could be longer or much shorter.
How Long Will a Battery Last?
A rechargeable battery will gradually lose its ability to hold a charge over time. Generally, a battery can hold a full charge for between 500 to 800 charge/recharge cycles. A charge cycle is the total depletion and then recharge of the battery. But most people don't run the battery down every time before they charge it. Batteries should last an average of between one and three years.
Storing a Battery
If you won't be using your cordless phone for an extended period, you should properly store the battery to maximise its life. Run the battery down to approximately 30% of the charge and remove it from the phone, if possible. Store the battery in a cool, dark place such as the door of your refrigerator--not the freezer!
Recycle Rechargeable Batteries
When it's time to replace your rechargeable batteries, don't just throw them in the trash. Batteries contain metals such as mercury, lead, cadmium, and nickel can pollute the environment if not disposed of properly. Some states, like California, require that you recycle your old batteries. You can look up where to recycle your used batteries in Resources below.