AA batteries are perhaps the most common, most used type of battery worldwide. Virtually every tool, device, and toy will use them.
It stands to reason that when buying these batteries in bulk, you want the best value for your money. You want a battery that lasts longer is protected, and won’t compromise the device it’s powering.
This article will explore everything you need to know about the runtime of an AA battery. We’ll discuss the different types of AA batteries, compare their chemistry, highlight their best uses, and highlight ways you can help preserve the runtime of whatever battery you choose.
What are AA batteries?
The AA battery, also known as the double A, is a single-cell cylindrical dry battery. Dry batteries are less prone to leaks because they use a specialized paste inside.
A typical AA battery has a power output of about 3.9 watts per hour, making it an ideal power supply for small electronics and power tools.
The AA battery comes in two forms:
- Primary cells are single-use disposable batteries that must be disposed of when exhausted.
- Secondary cells are rechargeable and can be used multiple times.
A variety of things influence how long a typical AA battery can perform. Everything from the device it is powering, to environmental conditions, to the battery’s chemistry all play a part.
Below we will explore the most common types of batteries and compare how they perform against each other in normal circumstances.
How long does the power last in an AA Battery?
There are several different material types used for AA batteries; each one impacts how long the battery can hold its charge. Let’s go through the most common and popular battery types.
1. Alkaline AA batteries
Alkaline batteries are perhaps the most common AA battery, for a good reason. They are both affordable and mid-tier in terms of power (1.5V), allowing them to power small devices like TV remotes, flashlights, and toys, to more demanding gadgets like shavers, handheld kitchen tools, and power tools immediately.
The batteries are built to last, offering between three and five times the capacity of an acidic cell. With an average power of about 2,500 mAh, you can expect a regular AA battery to perform consistently for 2 hours on high-powered devices. Brands like Duracell promise 10-20 hours of use on low-powered devices like flashlights.
Although they can come in rechargeable form, single-use is the most popular and mass-produced version of the alkaline battery. They are found in virtually every shop worldwide. Batteries typically have a shelf life of between 5 and 10 years, making them an inexpensive investment.
Other downsides to using an Alkaline battery include potential leakage from batteries over long periods of time. Because they are so popular, many brands have entered the market to produce them, leading to discrepancies in quality and effectiveness.
Alkaline rechargeable batteries are typically not well suited to high-drain appliances you constantly use daily. For that reason, it’s a good idea to buy from reputable brands and to regularly check the condition of batteries in devices and examine them for signs of corrosion and damage.
2. NiMH Rechargeable Batteries
The most common rechargeable AA batteries on the market are nickel metal hydride batteries, otherwise known as NiMH batteries.
NiMH batteries are less likely to leak than Alkaline batteries, although their cell voltage is generally lower. They can also self-discharge at between 0.5-4% per day and may require frequent charging. Therefore, they are an ideal battery for low-power-hungry devices like electronic toothbrushes or flashlights.
Of course, one of the most popular reasons to buy NiMH batteries is because they are rechargeable. You can expect upwards of 700-1000 battery life cycles per battery, equaling about 2-3 years of use. This makes them a cost-effective option versus single-use batteries.
That said, they have an output typically lower than Alkaline batteries at between 2,000-2,500 mAH. Furthermore, NiMH batteries are that they can suffer from overcharging. If you leave them in the charger for too long, their internal power cells can become damaged and lose their capacity to hold an adequate charge. For this reason, we recommend investing in a high-quality charger that terminates charging when batteries have reached their capacity.
3. Lithium Batteries
Traditionally, lithium batteries were only found as small batteries in wristwatches, alarm clocks, and calculators. But modern AA versions have capitalized on lithium’s proven track record for long-lasting power supply.
One of the best features of lithium batteries is their high charge density. Their runtime can be up to eight times higher than traditional Alkaline batteries, and their mAH ratings are consistently higher, too.
This means they are an ideal choice for high-power tools or for powering low-demanding devices for long periods, e.g., smoke detectors. But they also have a higher voltage, meaning that the device must be capable of handling this higher power.
Because of their protective casing, lithium batteries are some of the safest batteries to use and, under ideal circumstances, will not leak or compromise a tool.
That said, lithium batteries are single-use. Modern consumers may be more inclined to invest in reusable, rechargeable batteries.
4. Lithium-ion batteries
Lithium-ion batteries, also known as Li-ion batteries, are the rechargeable version of lithium batteries, offering a long-term, cost-effective and powerful service. Li-ion batteries come in various sizes and strengths and are the common choice for your mobile phone or laptop.
The AA version, the 14500 li-ion battery, promises high capacity at 2000mAh, capable of working up to 8 hours before requiring a charge. Additionally, the batteries tend to have a higher voltage than other AA batteries, between 3.6–3.7, meaning they can power the most demanding of tools around the home.
Depending on the type, li-ion batteries can have an incredible 2,000-3,000 battery charge cycle, meaning they can last three times longer than competing AA batteries.
One thing to note is that lithium-ion batteries often have slightly longer dimensions than regular AA batteries. You should check your device’s manual to see if it will physically fit into the battery compartment.
What impacts battery lifespan?
Below are some factors that can improve or reduce your battery’s lifespan, capacity, and runtime. Take these into consideration when working out how long a battery should remain functional:
- Type of device: High-drain devices (usually 3V or higher) will deplete a battery’s power more quickly. Low drain devices (1.5V and under) will run for longer.
- Use: Tools used for longer periods and every day will deplete a battery’s runtime versus those used sparingly every other day. Also, consider features and power modes; digital cameras, for example, may consume more or less power depending on quality and flash use.
- Storage & temperature: Higher temperatures increase the number of chemical reactions inside the battery, shortening its lifespan considerably. Store them in a cool, dry place like a plastic box to avoid short-circuiting.
- Compatibility issues: Underperforming batteries will die quicker if incompatible with the device. Similarly, too strong a battery can damage a tool’s inner circuits.
- Brand: With so many manufacturers in the business, some battery brands are known to work better, for longer, and with fewer performance issues.
- Avoid mixing: Many modern devices require multiple AA batteries to function. Avoid mixing different brands, as some may work harder to compensate for weak-performing ones, leading to faster discharge. Try to use batteries that came in the same pack.
- Recharging: A rechargeable battery performs only as well as its charger allows. Invest in high-quality, branded chargers to ensure your batteries are fully powered and not running on half-steam. Never leave rechargeable batteries in their charger overnight. This can lead to overheating and lead to quicker degradation.
- Dimensions: While Li-ion batteries have some of the longest running times, they often come in various sizes. Always check they can safely and securely fit your electronic device before investing in them.
AA batteries power so many things that it is virtually impossible to live without them. These small, powerful batteries can do so much – and more, if we invest wisely.
A variety of different materials and brands makes deciding between AA batteries an important thing to consider. Some single-use batteries can last longer than rechargeables but must be disposed of afterward.
In this article, we’ve detailed the most common types of batteries on the market. We’ve explored their similarities and differences and highlighted how many hours you can expect them to perform.
Please comment below if you still have questions about how long AA batteries last. But if in doubt, remember these three critical points about AA batteries:
- Single-use batteries often have a larger capacity and longer running time than rechargeables.
- Rechargeable batteries offer a more cost-effective route for batteries and can be used continuously for up to 3 years.
- Some batteries, like Lithium-ions, have slight differences in dimensions. Always check your device’s manual for compatibility issues.