DeWalt 5Ah Battery Comparison: PowerStack vs XR vs 6Ah XR

Introduction

Amp hours are not the whole story. In our testing of three popular DeWalt packs, the PowerStack 5Ah, the XR 5Ah, and the XR 6Ah, we found a lot of variables that explain why some buyers will want the PowerStack, and why others may happily save some money and go with the 6Ah XR instead.

The headline: 5Ah is 5Ah, but how each pack holds its voltage on the way down is very different, and that difference matters more than most buyers realize.

Why Voltage Sag Matters More Than Runtime Alone

One of the things most of us do is purchase tools based on the performance we see at full battery power. But what would these tools do at half a battery? That is far more realistic for how most people actually use their tools. If you are driving lug nuts with an impact wrench, by the fourth, tenth, or fifteenth tire, are you still getting anywhere near the peak performance that convinced you to buy the tool?

That is why voltage behavior under discharge deserves attention. A battery that holds a higher voltage through most of its drain keeps the tool performing closer to its peak for longer. A battery that sags early may feel strong on the first pulls and noticeably weaker later on.

How We Tested

We ran each pack on a heat gun and logged the drain in 30-second intervals, tracking how the voltage slowly fell until each battery cut out.

One correction from earlier testing: we initially ran the XR 5Ah and PowerStack 5Ah without a voltmeter connected and concluded their runtimes were very similar. That was true, but the ending voltage told a more nuanced story. All of these batteries bounce back a little in voltage once they cut off, and the bounce-back rate differs. The XR 5Ah has a pretty slow bounce-back, so you can watch it recover gradually. The PowerStack, on the other hand, snaps back very quickly the moment it turns off, which makes its exact cutoff point harder to catch. The 6Ah XR also bounces back slowly.

DeWalt XR 5Ah: Popular, But Not the Highest Performing

The XR 5Ah is probably the most popular DeWalt battery pack out there, and it is a great balance of power and size. But in our drain test it depleted itself quite quickly toward the end. The voltage fell through the 15s and 14s, dipped into the 13s, then cut out in the low 11-volt range, we saw around 11.08 volts. The BMS appears to cut it off once it hits around 11 volts, and at that point it was falling fast.

In terms of runtime on the heat gun, it went for roughly 17 minutes 30 seconds, give or take a few seconds, which was the longest of the two 5Ah packs in this test.

DeWalt PowerStack 5Ah: Higher Voltage Under Load, Harder Cutoff

The PowerStack told a very different story. As it drained, it held a noticeably higher voltage for much longer. We did not see much time in the 14s, and no long stretches in the 13s at all, because it simply stayed above that range until the end. It cut out at 12.10 volts, which suggests the BMS cuts off around 12 and we just caught it at 12.1 as it snapped back.

That higher sustained voltage is likely thanks to the 21700 cells, which really do hold voltage higher than many other cells. Where the PowerStack gave back some ground was runtime: on the heat gun it ran for 16 minutes 26 seconds, almost a full minute less than the XR 5Ah this time around.

DeWalt XR 6Ah: The Value Play With Real Runtime

The 6Ah XR behaved much like the XR 5Ah at the end of its discharge. It died fairly quickly, did not live in the 13s for long, passed through 12.10 volts, and cut off at around 11.08 volts, again likely a BMS cutoff near 11.

Where it shines is endurance. It ran the heat gun for a full 21 minutes, the longest runtime in this test, and it seemed to hold voltage pretty well throughout. If you mostly want longer runtime between charges and do not need the highest sustained voltage under heavy load, this pack makes a compelling case.

Which DeWalt Battery Should You Buy?

It is tough to call a single winner, because the right answer depends on how you use your tools. The PowerStack holds voltage higher for longer, which matters most when you push a tool hard, and it already proved itself on high-draw drills in earlier testing. The XR 5Ah remains a great balance of power and size and the natural default for general use. The XR 6Ah gives you the most runtime per charge and a lower cost per amp hour.

This heat gun test is really a precursor to a bigger circular saw test, which should show more clearly what these packs hold when serious power is demanded from them. Mechanics and heavy users, in particular, should care about the tool that holds peak performance highest across the whole discharge range, not just the one that peaks at full charge and dives quickly afterward.

Conclusion

Three packs, three personalities. The PowerStack 5Ah holds its voltage higher than the rest and cuts off hard, the XR 5Ah edges it on raw runtime while staying the most versatile all-rounder, and the XR 6Ah delivers the longest runtime of the group. Watching how these batteries drain and where they hold voltage is one of the better ways to decide which pack deserves a spot on your next purchase, especially if you find one at a great deal.