The most thing to do with batteries is to keep them fully charged when not using them. They will slowly lose power when not plugged into a charger or in the device they are charged with, so you should always charge them completely before taking them out.
heat is another factor in the destruction of laptop batteries. Laptop batteries can also heat up while the computer is on, so if you are plugged into a wall, and don't need the battery, take it out of the laptop and set it aside. 90% of all laptops will run without the battery in them when the laptop is plugged into the wall.
You should always try to keep your battery charged, so if you don't use the battery for a month or so, put it back into the laptop and charge it up again. By doing this you will prolong the life of the laptop battery.
The batteries for these devices should be taken out of the unit when not in use. Make sure they are fully charged at least once a month.
Radio batteries should be given a full charge after every use. For Nicad radio batteries, you should never take them off the charger until they have been fully charged. Nickel-metal hydride batteries can be used even if they haven't received a full charge. It is not adviseable to leave your radio batteries on the charger unattended. With so many fly-by-night manufacturers, it is best to not leave any radio battery on the charger for more than 12 hours.
Lead acid batteries should never be overcharged. They can boil the electrolyte and destroy the battery. They can also explode, crack and leak, or destroy the device they are intended to power. Never run down your lead acid battery to Zero capacity. That damages the battery.