Rechargeable battery buying guide: How to find the best batteries for all your devices
Learn how to compare batteries from Duracell, Energizer, Eveready, Panasonic and more.
Quick fact about rechargeable batteries:
- Buying rechargeable batteries is an investment, so you need to be sure you're getting reliable long-term performance.
- When choosing batteries, consider what gadgets you want to power with your batteries and how much you're willing to spend.
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:
Rechargeable batteries are available in standard battery sizes including AA, AAA, C, D and 9V. It's always a good idea to double-check that you're selecting the right size of battery for your electronic devices before you buy.
Check how many charge cycles the manufacturer claims you will be able to get out of a battery. Some claim up to 300, 500 or 1,000 uses, while some pricier options can be recharged more than 2,000 times.
Low-self discharge (LSD)
Low-self discharge batteries, which are sometimes also referred to as "ready to use" or "pre-charged" batteries, are NiMH batteries that are specially designed to better retain their charge when not in use. The fast rate of self-discharge is a common criticism of regular NiMH batteries, which lose about 1% of their charge per day, so it's worth checking how much charge you can expect a battery to maintain during a long period of inactivity.
The capacity of a battery is measured in milliamp hours (mAh) – the higher the mAh figure quoted on the box, the more usage time you'll get out of the battery. This means a 2,500mAh battery will be able to power a device for longer than a 1,300mAh battery, but it will also take longer to charge.
If you care about the environment, you may want to consider one of the several products available that are manufactured in part from recycled materials, including recycled batteries.
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