How do you fix cellphone batteries?

Fixing cellphone batteries typically involves replacing them rather than repairing them, as most modern smartphones have non-removable batteries. To replace a battery, you'll need to carefully disassemble the phone using the appropriate tools, such as a heat source to soften adhesive, suction cups, and screwdrivers. Once the phone is open, disconnect the old battery and install a new one, ensuring all connections are secure before reassembling the device. Always prioritize safety by following manufacturer guidelines and using quality replacement parts.