Rechargeable battery buying guide

Why buy rechargeable batteries?

It wasn't all that long ago that rechargeable batteries were widely seen as being unreliable and offering poor performance compared to their single-use cousins. However, modern technology allows rechargeable AA and AAA batteries to hold a much larger charge, retain their charge for longer and go through hundreds of charge cycles.

As a result, there are a few simple reasons why rechargeable batteries are a sensible purchase:

• They're cost-effective. While prices and performance vary between brands, you'll generally start to get value for money from rechargeable batteries after about a dozen (or sometimes fewer) uses. While they might cost more than single-use batteries up front, the extra investment is worth it in the long run.
• They're better for the environment. Single-use batteries need to be disposed of as soon as they run flat, but rechargeable batteries can be reused hundreds or thousands of times. While rechargeable batteries still contain toxic chemicals, they're much better for the environment than throwing out hundreds of single-use batteries.
• They can power a wide range of devices. Torches, wireless mice, wireless keyboards, remote control cars, TV remotes, portable media players, kids toys – the list of high-use household gadgets powered by batteries is a long one, so there are plenty of ways you can use rechargeable batteries around the home.

Rechargeable vs single-use batteries

While rechargeable batteries have their advantages, there are some situations where single-use batteries are a better choice. For clocks and those devices that you only need to power every so often, such as an emergency torch you only use during power blackouts, single-use alkaline batteries are the preferred option.

Single-use batteries are designed to kick into action straight away after extensive periods of inactivity. And because they'll only be used sparingly and won't need regular replacement, you can take advantage of the cheaper price tag.

What types are available?

There are three main varieties of rechargeable batteries:

Nickel-cadmium (NiCd) rechargeable batteries

Once the leader of the rechargeable battery space, newer technology that offers better performance has superseded nickel-cadmium batteries. Cadmium is also highly toxic, which has prompted the European Union to restrict its use in batteries to all but a handful of medical applications.

Nickel-metal hydride (NiMH) rechargeable batteries

Most modern rechargeable batteries are made of nickel-metal hydride, which provides a larger capacity and the ability to hold a charge for longer. They're cheaper to manufacture than NiCd batteries and are a suitable choice for most household applications.

Lithium-ion (Li-ion) rechargeable batteries

Lithium-ion rechargeable batteries have emerged in recent years and are capable of holding a higher capacity and offering a longer shelf life than NiMH batteries. However, they're rarely available in standard sizes like AA or AAA as they often have too much power for most consumer devices – most operate at 3.7V. If you do decide to buy a Li-ion rechargeable battery, make sure it has a voltage of 1.5V or 1.2V.

How to compare rechargeable batteries

Once you know which type of battery is the best choice for your needs, you can start comparing rechargeable batteries based on their size, capacity, lifespan and cost.

Rechargeable battery prices vary depending on the brand and size of battery you purchase, Remember to consider the number of batteries in a pack to make sure you're comparing apples with apples. As a general guide, a four-pack of AA rechargeable batteries will cost somewhere in the $15-$35 range.

Don't forget to also include the cost of a battery charger in your calculations if you don't already own one – most are around $20-$40.

Here are the additional key factors you'll need to consider: