Rechargeable batteries are a great way to save energy and reduce the environmental impact of batteries. However, they come in a variety of types and sizes, as do their chargers. It is important to distinguish between these types before purchasing a charger and batteries to use with it.
Most chargers either charge NiMH, NiCd, or both. Some charge rechargeable alkaline or other less-common types. Chargers which can only charge small battery sizes (AA, AAA, and/or 9V) are cheaper and more compact, but they restrict the types of batteries you can use and may lead to purchasing another charger later on. Most chargers have a charging time ranging from two to twenty hours. The charging time may vary depending upon the battery size – “AAA” batteries generally charge faster than the “C” or “D” sizes, for example. Most units have lights which turn on when the batteries are being charged, some also have a feature which turns the lights off after they are finished charging. Most chargers plug directly into the wall, use a built-in power cord, or have an AC adapter. A few have a built-in DC plug which allows them to be connected to an auto cigarette lighter, and some can be outfitted with a power cord of the same type. For even greater energy efficiency, solar battery chargers are available as well. Charger brands include Archer (made by Radio Shack), Quest, Energizer, and a number of others. Chargers can be purchased at electronics, department, and grocery stores, as well as internet auctions and shopping websites.
Although some less-common types are in use, NiCd and NiMH are the most common rechargeables. Both types have some advantages. NiCd batteries are usually less expensive than NiMH. They also work in some older electronic devices (like older cordless telephones) which cannot accept other battery types. On the other hand, NiMH is preferable for some modern devices like digital cameras, and they are more widely available. eBay and Radio Shack are two sources of NiCd batteries, while NiMH can be found at many grocery and department stores as well. Be sure to refer to the instructions of photographic equipment and devices with built-in chargers (some radios have these, for example) to determine what type of batteries are safe to use. Batteries with a higher mAh rating can hold more energy, meaning they will last longer after each charge. It is preferable to purchase the charger before the batteries, as some chargers are sold with batteries included.
A battery tester can be a useful accessory for your battery charger. Some charging units warn against simultaneously charging batteries with different amounts of energy in them, so a battery tester helps you avoid doing this. It can also allow you to determine if a particular battery is causing an electronic device to function improperly, rather than the entire set of batteries you are using.
Taking these factors into considerating, you should be able to find a charger and batteries which are suitable for your budget and the electronic devices you plan to use them with.
