How to Charge a Cordless Drill Battery

On this page (8 sections)

1. How do you charge a cordless drill battery step by step?
2. Why does the battery and charger pairing matter so much?
3. How long does charging take, and what do the lights mean?
4. Can you leave a drill battery on the charger?
5. What should you do when the battery won't charge?
6. How should you store and look after drill batteries?
7. When is a battery ready to go back in the drill?
8. What are the most common charging mistakes?

Put the battery in its matching charger, push it fully into the slot, and leave it until the charger says the cycle is done. Then pull the pack, let it cool, and store it at room temperature.

Knowing how to charge a cordless drill battery correctly is mostly about the small habits: the right charger, a clean connection, and a pack that isn't cooked or left flat. Get those right and the drill is ready when you need it.

How do you charge a cordless drill battery step by step?

Seat the pack in the charger made for it, watch the indicator, and remove it when the cycle ends. The order is simple, but each step matters for a pack you want to keep in service.

Start with the drill switched off and the battery removed from the tool. Match the pack to its own charger: brand, voltage, and slot type.

Push it down until it clicks or bottoms out, then check the light.

Most kit chargers show charging and charged states with different colors or a blink pattern. Trust that signal over guesswork.

When it reads full, slide the pack out rather than leaving it parked there for days.

Let a warm pack cool on a dry surface before you use it again. A battery that just came out of hard drilling charges better after a short rest.

Why does the battery and charger pairing matter so much?

Use the charger that came with your drill kit. Voltage, contact spacing, and slot shape differ between brands and even between model lines, so a pack from one system won't seat or charge properly in another's dock.

Lithium-ion packs from DeWalt, Bosch, and Skil each have their own slide-in design. The DeWalt DCD771C2 kit pairs its 20V MAX batteries with a DeWalt charger; the Bosch PS31-2A kit pairs 12V Max packs with a Bosch charger.

A 20V pack doesn't go into a 12V dock, and forcing it is how you damage contacts.

The charger also manages the cycle. It tapers the current near full and, on many models, stops it altogether.

That management is built around the pack it shipped with, so a mismatched setup gives up that protection.

If you've lost the original charger, buy a replacement from the same brand and the same voltage. Check the model number on the pack and match it to the charger's supported list before you order.

How long does charging take, and what do the lights mean?

Expect a compact pack to fill faster than a large one, and let the light tell you when it's done. Charge time follows battery capacity and charger output, so there's no single number that fits every kit.

A 2.0Ah pack and a 1.3Ah pack in the same brand family won't take the same time on the same dock. The DeWalt kit's batteries and the Skil kit's PWR CORE 20 2.0Ah pack both charge in their own chargers at rates the maker sets.

Read the light pattern in your manual once and remember it.

Common patterns are steady red for charging, steady green for full, and a blink or alternating color for a fault or a hot pack. A fault light usually means the pack is too warm or the contacts need cleaning, not that the battery is dead.

Don't judge a charge by how warm the pack feels. Heat during charging is normal to a point; heat after hours on the dock is your cue to pull it and let it cool.

Can you leave a drill battery on the charger?

Only if your charger manages a full pack. Many modern chargers stop the current when the battery reaches full, so an overnight stay does no harm.

Others keep a trickle going, and those are the ones to unplug.

Check the charger's own instructions rather than guessing. If it says to remove the pack after charging, do that.

If it says the pack can stay, you can leave it docked without worry.

Storage is the bigger issue. A pack left in a hot garage or a sunny truck cab ages faster than one kept indoors.

Heat is the main enemy of lithium-ion cells, and a charger sitting in the sun makes it worse.

Pull the pack when the drill goes back in its bag. It's a small habit that keeps contacts clean and stops the charger from sitting powered for no reason.

What should you do when the battery won't charge?

Check the outlet, the seating, and the contacts before anything else. Most charging failures are simple: a switched-off outlet, a pack not pushed in far enough, or dirty metal on the slides.

Try a different outlet and a different slot if your charger has two. Wipe the contacts on the pack and the charger with a dry cloth; never use liquid or a metal tool on them.

Then reseat the pack firmly.

If the light still shows a fault, stop. Don't force the pack, don't open it, and don't try to charge a pack that's visibly swollen or cracked.

Contact the maker's support with the model number, and recycle the pack at a proper battery drop-off if it's failed.

A pack that charges but drains in minutes is worn out. Replacement packs from the same brand keep the drill running without changing the tool.

How should you store and look after drill batteries?

Keep packs dry, cool, and partly charged. A drill battery is a long-term purchase, and storage habits decide how many cycles it gives you.

Store packs indoors, out of direct sun, and away from a hot garage shelf or a cold shed. Room temperature is the goal.

Don't leave a pack in the drill bag in a hot car, and don't stack heavy tools on top of it.

Leave a used pack partly charged rather than flat. Lithium-ion cells don't like sitting empty for months.

If a pack won't be used for a while, top it up to about half and check it now and then.

Keep the contacts clean and the pack dry. A damp pack goes on the charger only after it has dried fully.

The kit products below each come with their own battery and charger, which keeps the pairing simple. The DeWalt delivers 300 unit watts out, the Bosch bare drill weighs about 1.8 lb while its kit weighs 3 lb per the spec, and the Skil kit runs a brushless motor with 400 in-lb of torque.

Pick the one whose battery system you'll actually keep charging.

When is a battery ready to go back in the drill?

When the charger says the cycle is done and the pack feels cool to the touch. Slide it into the drill until it clicks, then check that it's locked before you squeeze the trigger.

Run the drill briefly to confirm it has power. If the pack wobbles or won't lock, pull it and check for debris in the tool's slot.

Charging is also a good moment to look over the tool. A bit that's worn or loose wastes battery, so swap it before the next job.

Our guide to how to change a drill bit walks through the chuck and bit swap.

If the next job is masonry, read how to drill into brick first; the right bit and a fresh pack save a lot of time. For metal, see how to drill through metal.

And if you're buying a drill for winter ice fishing, the cordless drill for ice auger guide covers what to look for in the battery.

What are the most common charging mistakes?

Forcing a pack that doesn't fit, charging in the heat, and leaving a flat pack for months are the three habits that shorten battery life fastest. Each one is easy to avoid once you know it.

• Shoving a pack into the wrong dock bends contacts. Match brand and voltage every time.
• Charging in a hot garage or a sunny spot pushes the cells harder than they need.
• Leaving a pack flat for the off-season is worse than leaving it half charged.
• Ignoring a fault light and charging anyway can turn a cheap fix into a dead pack.

The fix is simple: charge in a cool spot, use the matching dock, pull the pack when the light says full, and store it partly charged. Your drill will be ready whenever the next job starts.

For anyone wondering how to charge a cordless drill battery without shortening its life, the routine is the whole answer. Match the charger, watch the light, keep the pack cool and dry, and store it indoors.

Do that and each pack lasts through a lot of drilling.

Frequently asked questions

How long does it take to charge a cordless drill battery?

It depends on the pack's capacity and the charger's output, so a compact pack usually fills faster than a large one. Most kits stop the charge on their own, and the charger light tells you when the cycle is finished.

Can I leave a cordless drill battery on the charger overnight?

Only if the charger is designed to manage a full pack. Many modern chargers stop the current when the battery is full.

If your charger's instructions say to remove the pack after charging, follow that rather than leaving it connected.

Why is my drill battery not charging?

Start with the simple checks: the charger is plugged into a live outlet, the pack is seated all the way in the slot, and the contacts are clean and dry. If the light still shows a fault, stop and contact the maker's support instead of forcing the pack.

Should I drain a cordless drill battery before charging it?

No. Lithium-ion packs don't need a full drain, and running one flat can make it slower to charge.

Top up a partly used pack when it's convenient, and keep the battery away from heat while it charges.

How do I store drill batteries so they last longer?

Keep packs in a dry spot at room temperature, out of direct sun and away from a hot garage shelf. Leave them partly charged rather than empty, and slot each one into its matching charger when it's time to work again.