Battery Depot

How to Care for NiMH Batteries

Rechargeable NiMH (nickel-metal hydride) batteries are a necessity for power-hungry devices such as digital cameras, which can quickly drain conventional alkaline batteries. However, whereas alkaline batteries require little maintenance, NiMH cordless drill batteries do need special care to not only extend their lifetime, but also to avoid potential dangers.

Remove NiMH batteries from the charger if you don't plan on using them for more than a month.

Do not drop the batteries onto hard surfaces, as this behavior could expose the corrosive materials inside the battery case.

Do not attempt to incinerate NiMH batteries or expose them to excessive heat. Batteries can explode if you toss them in a fire or place them near other extreme heat sources.

Fully charge your NiMH batteries and do not charge them again until you fully drain them. An occurrence known as the "memory effect" can prevent rechargeable Bosch power tool batteries from fully charging if you don't regularly drain the batteries before charging them. Buy more than one set of NiMH batteries so that you have a charged set ready to go when your in-use set drains.

Clean the contacts on each end of your NiMH batteries with cotton (or a cotton swab) and isopropyl alcohol. Keeping the contacts clean ensures the batteries charge as quickly as possible.

Break in batteries by charging and draining them up to three times before use. This helps batteries run at peak performance and capacity and is useful not only for new Panasonic power tool batteries, but for batteries you place in storage.

DIY Rebuilding Tool Battery Packs

Rechargeable battery packs make using power tools much easier. You can use your tool anywhere and never have to worry about wires and plug sockets. Drill battery packs only last a certain time before they need replacing. The more you charge and discharge your battery, particularly NiCad batteries, the sooner its needs replacing. Replacement battery packs can cost 1/3 or more of the price a new tool costs, so the cost-effective way is to rebuild your existing battery pack.

Remove the battery pack from the tool. Look for small Phillips screws holding the pack together. Use a Phillips screwdriver to remove them. Put the screws somewhere safe.

Remove the cover from the power tool battery pack for Makita. Look to see how many battery cells are in the pack. The number varies, depending on the voltage requirement of the tool.

Pry out the battery cells, using a small electrical flat-head screwdriver. If they are soldered in place, heat a soldering iron, then touch the terminals and melt the solder. Quickly remove each cell before the solder solidifies. Turn off the soldering iron.

Get the same number of replacement cells as in the battery pack and the same type. Take a battery cell to your electrical store so your get the correct replacements.

Insert the new battery cells in the battery pack. Simply push them in, or if you used a soldering iron to remove them, heat a soldering iron. Put each battery cell in the pack/ Then touch a battery terminal with your soldering iron and introduce the solder. Let the solder melt, then remove the solder and soldering iron. Repeat the process for each battery cell. Turn off the soldering iron.

Replace the cover on the battery pack and screw in the screws using a Phillips screwdriver. Replace your battery pack in your power tool and charge the pack for a short while.

Some power tool battery packs for Craftsman are sealed units. It's best not to try to open them as you will damage the pack. Purchase a replacement, but ensure it has screws so you can replace the battery cells if you need to.