A Complete Guide to AA Batteries

AA batteries are one of the most common types of swappable power cells in circulation today. They’re what many of us typically picture when we think of the ‘classic’ size and shape for a standard replaceable battery.

Often used in single cell devices, or combined into pairs (or larger multiples) for powering larger but still relatively portable consumer electronics, AA batteries are incredibly versatile and very widely available almost everywhere in the world.

In this guide, we’ll give a rundown of numerous AA battery types, material variants and performance guidelines. We’ll also be looking at some common usage scenarios and frequently asked questions for AA batteries, to help clarify how to get the best from your cell-powered devices while continuing to use them safely and economically.

How long do AA batteries last?

When trying to figure out which AA batteries last the longest, there’s no hard and fast answer; it’s something of a ‘how long is a piece of string?’-type question. In practical terms, it will depend entirely on a wide range of factors, including:

• The application you’re using the batteries for, and the environment/conditions you’re using them in
• The type of equipment they’re installed in (especially high-drain vs. low-drain)
• The nominal voltage of the cell type in question, which for AA cells will usually be either:
• 1.5V, the standard nominal voltage for batteries of this size (AA 1.5V batteries are the most common and widely available versions, particularly of alkaline and zinc-carbon cells)
• 3v/3.6V, both reasonably common nominal voltages in batteries intended for use in high-drain applications (lithium cells are commonly sold as 3.6V AA lithium batteries)
• Whichever nominal voltage of AA batteries you’re buying, be certain that the device you’re intending to power specifies accepting units of that rating; using underpowered cells will result in performance issues, while overpowered batteries can easily damage components and circuits
• How intensive the workload they’re placed under is, and for how long at a time they’re kept in active use
• The quality of a given brand’s manufacturing processes and materials

Calculating and comparing expected AA battery life is an inexact science - or rather, it’s one with so many possible variables that it doesn’t always appear a like-for-like comparison once you start weighing up different cell chemistries for different usage scenarios.

With that said, the basic rules of thumb are as follows:

Standard alkaline AA batteries

• Won’t typically last very long in high-drain devices such as digital cameras; they can’t output their full power fast enough to cope with the demands of high-drain electronics especially well
• Can be prone to leaking when over-taxed or kept for long periods of time
• Are much better used in low-drain devices with fewer major spikes in power draw to content with
• Have a reasonably long shelf life when not installed, and are among the most economical types of AA battery in the short-term

Lithium AA batteries

• Much better than alkaline at coping with high-drain demands, and can last for years in the right sort of device
• Have a particularly long shelf life, and won’t leak over time
• Aren’t typically available in rechargeable varieties (see the comparison with lithium-ion versions, above)
• Tend to be more expensive than AA alkaline cells

Rechargeable AA batteries

• Likely a better bet for any devices that are going to be in heavy and/or regular use for extended periods of time, especially with higher-drain circuits
• Tend to be more costly in the short-term, but quickly become much more cost-effective than single-use cells (even budget alkaline disposables) if you’re going to be draining them quickly and regularly
• Are best bought in multiples of the amount needed for the device in question, so there’s always a replacement set charged and ready to go
• Will require a discrete charger, either bought separately or supplied as part of a bundle

Can AA batteries explode?

We’ve touched on the dangers of mistreating certain high-drain rechargeables - particularly li-ion batteries - in previous sections, but what about regular disposable AA batteries? Can they explode or rupture in dangerous ways? Well, while it’s very rare indeed for AA batteries to explode in typical day-to-day use, ruptures or even small explosions aren’t impossible.

When a standard AA alkaline battery is inserted into a circuit and starts to deliver power, there’s actually a chemical reaction taking place within the cell that produces small amounts of hydrogen gas. Most AA batteries from quality brands will be vented to allow for this. However, the fact that this gas is being generated under pressure inside a sealed metal chamber means that, should a product malfunction or be placed in a situation it’s not equipped to handle, issues can occur.

For most AA batteries, ‘exploding’ usually means a loud ‘pop’ sound and ejection of corrosive materials. When alkaline, NiMH and even lithium AA batteries rupture, the force and heat of the explosion isn’t anywhere near that of, say, an explosive li-ion failure - although it’s still potentially hazardous to users, and the causes should be investigated when safe to do so, along with contacting the manufacturer or supplier.

If you’re ever faced with a badly leaking, ruptured or exploded alkaline AA battery, the best procedure is to immediately and carefully wash all traces of ejected material off your skin. Once this has been done, any traces of this remaining lye material should be neutralised with a household acid such as vinegar or lemon juice - but only do so after removing as much material as possible with water, otherwise, an exothermic chemical reaction can occur, generating more heat.

If any material has made direct contact with your eyes, wash them thoroughly and seek medical advice. Once you’ve taken care of yourself, it’s important to clean any leaked material off components and contacts in the battery enclosure, as it can damage devices irreparably if left to degrade the metals. Again, vinegar or lemon juice on a cotton bud will be effective here, as will careful scraping with a flat screwdriver for any stubborn residue.

Are AA batteries allowed on planes?

Yes, AA batteries are allowed on planes, although there are some caveats and best practices you should be aware of:

• Dry-cell batteries, which include alkaline, lithium and NiMH rechargeable AA batteries, are allowed in carry-on luggage (both inside devices and as spares)
• With the exception of spare lithium AA batteries, which must only be carried on board, all of the above are also allowed in checked baggage
• However, it’s generally not recommended to put spare batteries in checked baggage if you can possibly avoid it - it might seem counterintuitive, but in the unlikely event of a problem, you’re far safer having them with you in your carry-on luggage where they can be accessed by staff trained to deal with such issues
• All spare batteries carried outside devices should be packed in a protective plastic case, individual plastic bags, or at the very least have their contacts taped over for the duration of air travel
• Never carry loose batteries in bags containing other metal objects (including coins, paper clips, zips etc), as this can cause them to short-circuit and become dangerously hot
• Consult your airline for advice regarding any spare rechargeable Li-ion batteries - these are generally allowed as carry-on, but are often subject to strict size limits

How do you store AA batteries?

Many AA batteries today boast impressively long shelf-lives, which is especially useful given that you can often enjoy considerable discounts when buying in bulk or larger multipacks. However, achieving optimal shelf-life for most AA cells depends on proper care and storage.

Tips to be mindful of when considering how to store AA batteries long-term include:

• Keep them out of the reach of children
• Ensure they’re stored in a cool and dry environment (room temperature or below)
• Where possible, keep them in their original packaging until ready for use - this not only helps to protect unused cells, but also differentiates them from older or partially drained units
• Don’t store batteries inside devices if you’re not going to be using them for a long time
• If you’re storing a mixture of brand new and partially used batteries, keep them separate and clearly labelled
• Make sure they’re unable to short circuit through direct contact with any other metal items - use a plastic battery storage box, individual plastic bags, or put tape over the terminals
• Periodically test and top-up rechargeable AA batteries, if they’re going to be stored for a long time, as letting them fully discharge in storage, can seriously deplete their capacity
• Never disassemble, puncture, crush or burn batteries of any kind
• Never store rechargeable batteries inside a charger, and never attempt to recharge a battery that’s not designed to do so

Why do AA batteries leak?

Batteries eventually leaking or corroding is a relatively common occurrence, especially familiar with alkaline AA cells if they’re left unattended for long enough. In short, the reason alkaline batteries leak is that they’re continually self-discharging in tiny increments, even when not in use.

Because the discharging process in alkaline batteries creates small amounts of hydrogen gas, pressure gradually builds within the sealed casing of the battery, and in time a small amount of material from inside the cell will often be ejected under this mounting pressure. This material is usually corrosive and should be removed from the skin immediately, then cleaned away from electrical components as soon as possible after that.

The best way to avoid leakage is to regularly replace older batteries, take note of the battery storage best practices outlined in the section above, and to switch to lithium or rechargeable cells for long-term storage if you only need to power a device very occasionally.

AA batteries are such a staple of everyday life that we often tend to purchase them without thinking much beyond the short-term, or stopping to consider what sorts of options might be available for giving our devices better performance or offering us better long-term cost-effectiveness.

However, it pays to look a little more closely into the various different chemistry types, voltages, shelf lives and recommended storage conditions for all kinds of AA batteries when deciding which cells to buy, use and reuse from a broad range of suppliers and manufacturers.

If you’d like any more advice or information on AA batteries, chargers and other accessories available in the UK, then feel free to contact a member of our expert support team any time.

Use the links below to view some of our popular brands: