Impact Driver Battery Testing Methodology

Impact Driver Battery Testing Featured Image

In the realm of power tools, the impact driver stands as an exemplar of efficiency and force, revolutionizing tasks that once demanded considerable effort. Yet, battery run time shouldn’t be overlooked amidst the array of features vying for attention.

A robust battery run time ensures uninterrupted workflow, minimizes recharge downtime, and empowers users to conquer demanding and long projects. These are critical factors when buying the best impact driver for your needs.

Below, we discuss our impact driver battery run-time tests, including a detailed methodology of how we test battery performance in our lab.

Check out our impact driver battery test results to compare the final results for each model in our test fleet.

What we test

We test each impact driver’s no-load battery run time in our test fleet. We plan to test battery run time under load in future updates to our battery testing methodology.

How we test it

We standardize testing to understand which impact drivers have the longest battery run time in relation to other models. Below, we further detail how each impact driver’s run time is tested.

Battery Ah capacity: We complete our run-time tests using a standard 2Ah-capacity battery from each brand. When a brand doesn’t include a 2Ah-capacity battery, we test the next highest capacity option.

For example, we tested Makita’s 40V XGT line with a 2.5Ah battery since Makita doesn’t offer a 2Ah version. We note in each review when not testing a standardized 2Ah battery. We calculate the run-time per Ah in these scenarios to help readers understand if the impact driver’s run time is comparably better or worse.

Here are the battery types tested for each platform of impact drivers:

  • Dewalt 12V: 12V Max 2Ah (DCB122)
  • Dewalt 20V: 20V Max 2Ah (DCB203)
  • Makita 12V CXT: 12V CXT 2Ah (BL1021B)
  • Makita 18V LXT: 18V LXT 2Ah (BL1820B)
  • Makita 40V XGT: 40V XGT 2.5Ah (BL4025)
  • Milwaukee M12: 12V Red Lithium CP 2Ah (48-11-2420)
  • Milwaukee M18: 18V Red Lithium CP 2Ah (48-11-1820)
  • Ryobi 18V One+: 18V One+ High Performance 2Ah (PBP003)

Fresh charge: Each battery is freshly charged before testing the run time to provide the most accurate results.

Environment temperature: Temperature can drastically affect battery performance. We test run time in our lab only when the inside temperature ranges from 60° to 75° Fahrenheit.

Auto shut-off features: Several brands include an auto shut-off feature that turns off an impact driver after running for a set period, usually at least five minutes. When a model shuts off automatically, we promptly re-engage the trigger with a clamp to continue testing. We deduct the downtime from the final result for accuracy.

Video recording: A video is recorded of each impact driver’s no-load battery run time for timing calculation purposes.

Final result: We round up the final run time to the whole minute. For example, 44.0 minutes and 31.0 seconds are rounded to 45.0 minutes.

Why it matters

When comparing two equally-matched impact drivers, we see little reason to choose anything but the model with the longer battery run time.

There’s nothing worse than grabbing your impact driver to start a job only to realize the battery is drained. That’s not a problem if you have another battery, so we recommend always having two. But it can be problematic to charge the battery before jumping in.

This potential for slowing down the time to complete a job and occasional frustration is why battery run time is factored into our impact driver rating methodology.

Nathan Hamilton
Nathan Hamilton
Nathan Hamilton is the founder of DIY Gear Reviews and a recognized expert in the home and DIY space. He has over 200 bylines covering topics such as power tools, hand tools, and woodworking. Nathan is the strategic director for DIY Gear Reviews, deciding everything from the content covered to designing the testing methodologies for lab-tested reviews. He can be emailed at


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