Cordless drill batteries are expensive so you will not want to have to keep buying those on a regular basis. These days, almost every cordless battery produced is classed as a Lithium-Ion battery.
Those have replaced the older style NiCad batteries, which discharged over time.
The best place to store cordless drill batteries is in a dry and cool environment that is free from dust. Ideally this should be at room temperature. You should store them separately to avoid terminal contact, and away from any other metal object.
Principles of Battery Storage for Cordless Drills
Most home owners will have just 1 or 2 batteries for their cordless drill that they use around the home. Depending on how you bought your drill will depend on whether they came with a case or not.
The better quality drills are usually supplied with a plastic, and in sometimes a lined metal case. There is usually battery storage provided within that case. Ideally that is the best place to store them.
If you haven't got a suitable case, then you can store the battery separately in something as simple as a plastic bag, or a small plastic container.
Avoid Humidity and Moisture
You should where possible try to avoid humidity and moisture. Inside the home is best for that. However if you want to keep your batteries in a shed or a garage, then just make sure they are not left sitting around.
Garages and sheds do tend to suffer from damp and mould in the winter time. That can impact on the battery, especially around the terminals where they attach to the drill or to the charger.
Wrapping the battery in an old cloth can stop any risk of damp, moisture and dust. It will also help preserve the life of the battery.
Store Batteries Separately
If you have more than one battery, then always store them separately. If terminals accidentally touch each other, then they can short circuit. That means the battery will drain quite quickly and it can also cause damage to the terminals and the inner cells of the batteries.
Wrap an old cloth around each battery, and then store them separately in a plastic tub or even a plastic bag.
Buy a Battery Mount
Some people refer to buy packs of wall mounts. You can attach these to a wall and then store the batteries on those.
You really only need something like that if you have several batteries for different power tools.
They are a great idea, as they keep each battery separate and also handy when you need to find them.
The ones shown here are for Dewalt, but you can also buy mounts for Makita and other brands.
Avoid Leaving Batteries in a Tool or a Charger
When batteries are not being used, it is always best to remove them from tools, and also to avoid leaving them sitting in a charger. That is because the battery is being used, or thinks it is being used, and will slowly drain.
Once a battery is fully charged, it should be removed completely and stored safely.
Why Store Batteries Properly?
It is really all about damage limitation. If batteries are left sitting around, then they are more prone to damage. They can get knocked over, have things spilled on them, and are open to the environment, which could be damp or dusty.
By looking after your batteries, they will simply last longer, and in reality it only takes a few seconds to do that.