The Battery Shuffle, and the One Drill Grandpa Still Plugs In

The hedge trimmer quit with eleven feet of hedge left to go.

Grandpa walked to the garage, pulled the battery out of the leaf blower, and found it dead too, because he'd cleared the driveway yesterday. The third battery was in the drill, where it had been sitting for a week on the shelf he swore he'd finish. He stood there holding three tools and one charger. The charger was blinking green like it was proud of itself.

"I own six tools and one heart," he told his granddaughter Maddie, who'd given him the kit for his seventy-fourth birthday. "It's a transplant ward out here."

Maddie reached into the box, which he hadn't fully unpacked, and handed him the second charger. He still hasn't lived it down. By supper every battery had a strip of masking tape on it: A, B, C, and one marked THE GOOD ONE.

What it says it does

A cordless tool line is a family of tools that share one battery system. You buy the batteries and a charger once. After that, you can buy each new tool "bare," with no battery, for a good deal less than the kit. The big names all run their own platforms (DeWalt, Milwaukee, Makita, Ryobi and others), and a battery from one brand won't fit another brand's tools without a third-party adapter.

The packs are lithium-ion. The two numbers on them matter. Voltage is the platform's power class. Amp-hours (Ah) is the size of the fuel tank, so a bigger number means longer runtime and a heavier battery. "Brushless" means the motor uses electronics instead of carbon brushes, which generally makes it more efficient, cooler-running and better on runtime than a brushed motor on the same battery.

The pitch is simple. No cords, no outlets, no gas cans. Grab the tool and go.

What Grandpa thinks it does

"The tool's the razor," he says. "The battery's the blade. And the blade can cost about what the razor does." He's not wrong. Check the current price of a large battery against a bare tool sometime.

He's fascinated by the labels. "Twenty volts max. Eighteen the rest of the time." This one's true. On most platforms, "20V max" and "18V" describe the same kind of battery, rated two different ways: peak and nominal. "That's not a battery," Grandpa says. "That's my fishing stories."

He admires the brushless motor out loud, and at length. "I've been brushless since 1988," he says, tapping the top of his head.

His favorite complaint is how the batteries quit. The old nickel-cadmium packs faded slowly, like a long goodbye at the front door. Lithium-ion tends to hold strong power most of the way and then stop. "My old drill told me it was tired," he says. "This one just leaves the party without a word."

Where he has a point

The batteries are the subscription. Every lithium pack wears down with charge cycles and age. Eventually you're buying new ones. Budget for that, because the tool will outlive several batteries.

You're married to the brand. Once you own four batteries in one color, the next tool you buy is going to be that color too. Pick the platform on purpose. Our guide on how to pick a cordless tool platform you won't regret walks through what to weigh before you commit.

Batteries hate extremes. Cold cuts runtime, and a pack left on a truck dashboard in July isn't having a good day either. Read the manual for the maker's storage and charging temperatures and follow them.

Some tools want your phone. A few higher-end lines connect to an app for tracking or settings. That's optional. If you use it, go through the permissions and turn off anything the tool doesn't need.

On safety, no jokes. Don't charge or use a battery that's cracked, swollen, has been dropped hard or has gotten wet. Don't buy bargain knockoff packs with no recognized safety certification. Charge on a hard surface you can see, away from rags, sawdust and anything that burns. And never leave a charger running in an empty house.

And then there's the drill. Grandpa's corded half-inch drill has outlived two cars and a dog. It's the one tool he still plugs in, and the reason is one job: mixing thinset, mortar and joint compound with a paddle.

That job is the worst thing you can ask of a battery. It's heavy, continuous load for minutes at a time. A cordless drill bogs down, heats up and can drain a pack halfway through a bucket. And thinset doesn't wait while you swap batteries. Once it's mixed, the clock on its working time is running. A corded drill pulls the same steady power until the bucket's done.

Mixing is also where a drill can hurt you. A paddle can catch, and a half-inch drill has enough torque to wrench your wrist or spin right out of your hands.

• Always use the side handle, with both hands on the drill.
• Run it on low speed.
• Seat the paddle in the bucket before you pull the trigger. Let it stop before you lift it out.
• Use an extension cord rated for the drill's amp draw and your run length. A cord that's too light runs hot and starves the motor. Check the drill's label and the cord's rating, and skip any cord with a cut or flattened jacket.
• Outdoors or near water, plug into a GFCI-protected outlet.

If you're tiling one bathroom and don't own a big drill, rent a mixer. It's one of the clearest calls in the tools you should rent and the ones you should just buy.

Where he is wrong

He'll admit it, and he does it with grace.

The ladder, first. A cordless drill on a ladder has no cord to snag your foot or yank the tool off the top step. "I once pulled a corded drill off a ladder with my own boot," he says. "Caught it with my forehead." Cordless wins that one outright.

The yard, second. Battery trimmers and blowers start with a trigger, not a pull cord. There's no gas mix and no stale fuel gumming up a carburetor over the winter. And they're much quieter at eight on a Saturday morning, which his neighbor appreciates more than anyone.

And the little jobs. Hanging a curtain rod used to mean finding the drill, finding the cord, finding an outlet behind the couch. Now it's a two-minute job. Pair a compact drill with an impact driver for screws and lag bolts (our breakdown of what to spend on a drill and impact driver covers that) and most household work is quick.

"Fine," Grandpa says. "The kid was right about the chargers too."

The verdict

Worth it, with conditions.

Cordless is the right call for nearly everyone doing household projects, yard work and anything off a ladder. Keep one corded tool, usually a half-inch drill, for long, heavy jobs like mixing. If you already have an old corded drill that still runs, it's already earning its spot. Don't let it go.

Three things to check before you buy:

1. Whether the platform sells every tool you'll want in the next five years. Look at the full lineup, not just the kit on sale.
2. The battery warranty, separately from the tool warranty. They're often different. Read the actual warranty document for length, what voids it and whether you have to register.
3. The bare-tool price against the kit price. If you already own the batteries, the kit is paying you for chargers you don't need. Check the current price on both.

Then label your batteries. Masking tape works fine. Save THE GOOD ONE for the hedge.