All good info.
Always charge your batteries outside of your scanner, preferably using a smart charger. Paul Opits (RIP) recommended charging outside the radio. Set the smart charger to the slowest charge rate available. This is where a smart charger pays for itself. Not only will the charger shut off automatically when the batteries are fully charged, and not continue to “fry” the batteries, most smart chargers allow for multiple charge rates where the lowest rate may take the longest but it will also be the coolest. It’s a given that heat is the enemy of all batteries. The less heat, the longer they last.