Find the Best Power Tool Batteries and Chargers

A power tool battery is a battery pack that contains several individual batteries or power cells connected together to power a cordless tool. The number of individual batteries and how they’re connected determine the battery power and runtime of the battery and the tool it operates.If you’re shopping for battery-operated power tools, they typically come with one or two compatible batteries. If you need spares or replacements, such as spare power drill batteries or a replacement battery for your cordless reciprocating saw, the tool brand and specifications will determine the batteries you can use. However, in either case it’s helpful to know what you can expect so you can make sure you’re getting the best power tool battery for your projects.

When comparing batteries, pay attention to the volts (V), the amp-hours (Ah) and the battery type. Then consider what types of tools the battery can power. Finally, make sure you have the right charger to make sure your battery is always ready to use.

One of the most prominent specifications you’ll see on a power tool or a battery is the voltage. The voltage of a battery, noted as volts (V), indicates the energy or power a battery can provide to a tool. More volts gives the tool more power. For example, a 24-volt battery can provide higher torque or rotational force to a drill, allowing it to bore into dense material quicker than a 12-volt model. Higher-voltage battery packs have more individual battery cells built in. More cells provide more power, but they also add weight, so the 24-volt battery will be heavier than a 12-volt battery of the same type.

How many volts do you need in a battery? It depends on the work you need to do. For general maintenance and repair work, a 12- or 20-volt tool and battery will suffice. They’ll handle the most-common tasks a homeowner might take on and will be lighter and more economical than a 24-volt or higher tool and battery combination. However, heavy-duty projects (such as building a deck or installing a fence) can benefit from the higher-voltage tools and batteries, so if you plan to take on large projects, the added weight might be worth it.

In addition to volts, look for the battery’s amp-hour rating (ampere-hour rating). The amp-hour rating (Ah) of a battery will be noted in the product information and may be printed on the battery along with the voltage. What does Ah mean? An amp-hour measures battery capacity or how much electrical current a fully charged battery can provide over a period of 60 minutes. While the actual time the battery can operate a tool varies by the level of current the tool needs to function, a higher amp-hour rating means a battery can operate the tool for a longer period of time.

Higher amp-hour batteries also allow a tool to use more of its available power to complete a job faster and can better maintain the power level. While the constant power level doesn’t benefit light-duty work significantly, higher-rated batteries are more effective for heavy-duty jobs, letting you complete the work more efficiently.

The battery amperage-hour rating you should look for depends on how you’ll use the tool it powers. As with voltage, you can handle a few light jobs effectively with a battery that has a lower rating. If you have a lot of heavier work to do, a higher amp-hour battery will more effective. It’ll weigh more, but will complete the job noticeably faster.

While there are several battery technologies that tool manufacturers have used over the years, two primary types are lithium-ion batteries and nickel-cadmium batteries. Lithium-ion (li-ion) batteries are the more recent technology of the two. They have shorter charge times than other battery types, and they maintain their power level as they discharge (the battery will supply the same level of power at a 30% charge as at a 90% charge). They can store more energy in a smaller, lighter battery pack and are available with higher amp-hour ratings. They’re not as affected by temperature extremes as other types. While these batteries don’t usually lose much charge when not in use, regular use can give them a better lifespan. It’s typically best to recharge a li-ion battery before it drops below a 20% charge level. Letting it become fully discharged can damage it. 

Nickel-cadmium (NiCad) batteries are better able to resist damage from impact than li-ion batteries, and they’re more economical. However, NiCad batteries can suffer from an issue known as memory effect. Regularly recharging a NiCad battery that hasn’t been fully discharged can cause the voltage of the battery to drop to the level where the previous recharge began. For example, if you regularly recharge the battery when it’s at 80% capacity, it may eventually only charge to 80%. This means if the battery voltage can decrease over time if the battery isn’t properly maintained.

Battery platforms, also known as battery systems, allow you to share batteries across a wide range of cordless power tools and, in some cases, cordless outdoor power equipment as well. With all your tools on the same battery platform, you don’t have to wonder which battery fits which tool or which charger. You won’t need as many chargers and, since you won’t be using all your tools at the same time, you won’t have to charge and maintain as many batteries. In addition, once you have a couple of batteries, you can consider purchasing tools sold without batteries (sometimes known as bare tools). A power tool combo kit is a simple way to get started with a battery platform.

Here are answers to some frequently asked questions about power tool batteries. 

What batteries are used in power tools?

Lithium-ion and nickel-cadmium batteries are two common types of batteries. Typical power tool batteries can range from 12V to 36V and are rated up to 9 Ah.

What’s the best cordless tool battery?

Lithium-ion batteries are often considered the best cordless tool battery since they deliver consistent power longer, charge faster and are easier to maintain, but nickel-cadmium batteries can offer an economical power solution suitable for many projects.

What power tools have compatible batteries?

Power tools that use the same battery system or platform can share batteries, allowing you to use the same battery to power a drill, an impact driver, a circular saw and more.

How long do power tool batteries last?

A battery’s cycle life indicates how many times it can be recharged before it needs to be replaced. NiCad batteries typically have a greater cycle life than li-ion batteries but lose power if not maintained properly.

Amp-hours indicate how long a battery can power a tool before needing a recharge. Li-ion batteries offer higher amp-hour ranges.

Cordless power tools, particularly those in combo kits, often come with the necessary charger. However, you may want to purchase an additional charger to keep several batteries ready to go. Make sure it’s compatible with your batteries (they often require specific chargers). Having all your power tools on the same battery system or platform ensures you’ve got the right charger. Here are some features to look for:

• Capability to charge batteries of different voltages
• Multiple charging ports to handle two or four batteries at a time
• A warning system that lets you know when a battery has stopped charging due to being too hot or too cold
• Fast-charging capability that uses higher amperage to charge a battery faster
• Multi-stage charge-level indicators that let you know when a battery is partially and fully charged
• Systems that communicate with the battery and monitor cooling and voltage to provide the best possible charge.
• A cooling system that dissipates the heat a battery builds up in use so the battery can recharge
• Wall mounts to allow you to save space on your work bench.

Follow the manufacturer’s instructions for use, charging, storage, transportation, and disposal of batteries and chargers. Use only the batteries specified for a particular tool or device and only the charger specified for a battery.

• Pay attention to the battery care. Proper battery maintenance lets you recharge and use batteries safely and ensures your batteries provide maximum power for the longest possible period of time.
• Brushless power tools make more efficient use of batteries, providing better runtimes and making more efficient use of the available power.
• Batteries with fuel gauges or power-level indicators help you make sure you have enough charge to complete a job and let you know it’s time to recharge so you can properly maintain your power packs.