How Long Does a Cordless Drill Battery Last?

Two different answers: per charge and per lifetime

People ask this question in two ways, and the answers differ. Runtime is how long the drill works before the battery is empty. Lifespan is how many months or years the battery keeps holding a useful charge before you need a new one.

Runtime depends on the task. Driving small screws takes little energy. Boring large holes in hardwood or running a hammer function drains a pack much faster. Lifespan depends on how often you charge it, how hot it gets, and how it sits between jobs.

What sets runtime on a single charge

The best number to check is battery energy in Wh, which combines voltage and capacity. Volts alone can mislead. A 20V pack with a small capacity can hold less energy than a 24V pack with a larger one. For example, the Greenworks DD345 lists 48 Wh with its 2Ah battery, while the DEKOPRO 20V set lists 30 Wh with a 1.5Ah battery.

Among the drills on our best cordless drill page that list battery energy, the range runs from 24 Wh to 48 Wh. A bigger number means more work per charge, though a larger pack can add weight.

Several other factors shape real runtime:

• Load: big bits, dense wood and metal use far more energy than small pilot holes.
• Speed setting: the high-speed range is for drilling, and the low range with more torque is for driving screws.
• Motor type: a brushless motor runs cooler and uses battery energy more efficiently than a brushed one.
• Temperature: very cold or very hot packs deliver less and wear faster.
• Bit condition: dull bits make the motor work harder.

What the listings claim for holes per charge

Some makers publish a holes-per-charge figure. These are manufacturer claims under their own test conditions, so treat them as a rough comparison and not a promise for your workshop. The BLACK+DECKER BLD782D1 lists up to 92 holes per charge for common DIY work, and the CRAFTSMAN CMCD702D1 lists up to 90 holes per charge. The DEWALT DCD806B hammer drill lists up to 175 holes per charge.

Notice that the two 40 Wh drills with a claim land close together, while the DEWALT figure is for a different tool type and a different test. Comparing claims across brands only works when the conditions match, which listings rarely say. Wh is the more reliable way to line up packs.

How long the battery lasts over the years

Lithium-ion packs wear a little with every charge cycle. Over time they hold less energy, and you notice shorter runs. With regular use, many packs serve for a few years. A homeowner who drills a few times a month may go much longer before noticing a drop, while a daily user will wear one out sooner.

The habits below slow that wear. They are general battery care and apply to most brands.

• Avoid running the pack completely flat again and again. Recharge when the drill slows down.
• Let a hot pack cool before charging, and let a cold pack warm up first.
• Store packs indoors, not in a hot truck or an unheated shed.
• For long storage, leave the pack partly charged, not full or empty.
• Keep contacts clean and dry, and use the charger made for that pack.

Charge time and leaving the battery in the drill

Charge time varies with pack size and charger output. Small packs on a fast charger can be ready in well under an hour, while larger packs on a basic charger can take a few hours. Check the charger label or manual for your model. The Greenworks listing, for instance, mentions a 30W fast charger with its USB-C battery, and the charger's power rating is the number to compare.

Leaving the battery in the drill between jobs is fine for a few days. For longer breaks, remove it so the trigger cannot be pressed by accident and so the pack is not sitting in a hot tool bag. Most modern chargers stop when the pack is full, but it is still better not to leave a pack on the charger for weeks.

Safety note: stop using any pack that is swollen, leaking, very hot or smells odd. Move it away from flammable items and ask your local waste program how to dispose of it. Never use a different brand's charger or pack unless the maker says it fits. Some drills, such as the AVID POWER set, specifically warn that they only work with their own battery.

Which batteries last the longest, and can you repair one?

For the most work per charge, look for the highest Wh rating you can carry comfortably, paired with a brushless motor. On our list, the Greenworks DD345 has the highest battery energy at 48 Wh and weighs 2.09 lb. If you drill often or work on heavier jobs, compare those numbers on our best drill page too. Hammer function drains packs faster, so check the best hammer drill cordless page if you need one.

Repairing a pack is rarely a good idea. Replacing cells means opening a sealed lithium-ion pack, and a mistake can cause overheating or fire. A safer fix is to buy a replacement pack that the maker approves for your drill. If the tool is old and the pack is hard to find, a new kit may be the simpler choice.

Safety note: always wear eye protection when drilling, and use hearing protection if you run a hammer drill for long stretches.

Frequently asked questions

How do I know when a drill battery is worn out?

Runs get noticeably shorter, the drill slows under light loads, or the pack gets warm quickly. If a fully charged pack cuts out soon after you start, it is near the end of its life.

Does a higher voltage mean longer runtime?

Not always. Voltage affects power, but runtime depends on total energy in Wh. A lower-voltage pack with higher capacity can run longer than a higher-voltage pack with a small capacity.

Can I use a bigger battery on my drill?

Only if the maker lists it as compatible. Some drills, such as the AVID POWER set, say they only accept their own pack and not a larger one.

Is it bad to charge the battery after a short job?

No. Lithium-ion packs do not have the memory effect older batteries had, so topping up is fine. Just let a hot pack cool first.