Voltage tells you less than you think. Two drills can both say "20V MAX" on the box and perform very differently once you're actually driving screws or drilling into hardwood. Torque, battery platform and motor type decide whether a tool lasts two years or ten.
What to actually look at
- Torque (in-lbs or Nm) — how much twisting force the tool can apply. Higher torque means it can drive longer screws or drill larger holes without stalling.
- Battery platform — many brands share one battery across their entire tool lineup. Buying into a platform you already own saves money on every future tool.
- Amp-hours (Ah) — this is runtime, not power. A 4.0Ah battery lasts roughly twice as long per charge as a 2.0Ah battery of the same voltage; it isn't twice as strong.
- Brushless vs. brushed motor — brushless motors run cooler, last longer and use battery power more efficiently, but cost more. Brushed motors are cheaper and perfectly fine for occasional use.
- No-load speed (RPM) — how fast the tool spins with nothing to resist it. Useful for comparing similar tools, less useful as a number on its own.
A quick spec-sheet cheat sheet
| Spec | What it tells you |
|---|---|
| Voltage | Battery family, not power on its own |
| Torque | How much force the tool can apply before stalling |
| Amp-hours (Ah) | Runtime per charge |
| Motor type | Brushless = longer lifespan, higher price |
| RPM | Speed, useful mainly for comparing similar tools |
Matching the tool to the job
Occasional home use, like hanging shelves or assembling furniture, rarely needs a high-torque, brushless tool. Frequent or heavy-duty use — framing, decking, repeated drilling into masonry — is where higher torque and a brushless motor start to pay for themselves in reliability.