After installation, place the cordless handset in its charger to charge for at least 10-12 hours before use. You can keep the battery charged by returning the handset to the charger after each use. -Q- Insert supplied battery. ONOTE: Use only the power cord supplied with this product. If you need a replacement, call 1-800222-3111. Be sure to use an electrical outlet not controlled by a wall switch. Caution: Use only supplied rechargeable battery (model 102) or AT&T replacement battery model