In this article and video review (see video below) we compare DeWalt’s regular 5 Amp Hour Max battery (previously called XR) with their 1.7, 3.5, and 5Ah PowerStack batteries (now called XR PowerStacks).
For me the regular 5Ah Max battery is still my go-to for DeWalt’s handheld 20V tools. It’s small enough to use on an impact driver, has enough runtime to swap it over to other tools, like a 6.5″ circular saw to make a few cross cuts and I don’t like carrying anything larger unless it can also run my DeWalt 60V tools. I run a 9Ah FlexVolt for those.
Which battery is right for you depends on your likes and needs but this review should help you decide which DeWalt battery is right for you.
The main pitch for PowerStack is DeWalt’s claim they deliver 50% more power, 50% more work per charge, and longer lifespan than Max batteries. Let’s get into it.
PowerStack vs Max
Basic Runtime Test
We, meaning I, ran a new 5Ah PS against a new 5Ah MAX on a 20V shop vac and they had the same runtime with the PS running cooler. In a later test we found the 5Ah MAX ran 2 minutes longer.
That said, for low power draw tasks it seems amps hrs is amp hrs with the real work capacity difference seen in power hungry tasks like cutting wood.
50% More Power
DeWalt says both the 3.5 Ah and 5 Ah PowerStack batteries deliver 50% more power than a 5 Ah MAX battery. In our testing the 3.5 and 5Ah PowerStacks ran faster than the 5 Ah MAX. It’s a difference you can feel, see, and hear.
50% More Work
In our non-scientific method testing full of unaccounted for variables, a new, fully charged, 5Ah PS with a new blade cut 78 feet of 2x lumber where a new 5Ah Max with its own new blade cut 56′ of that same lumber. The 5Ah PS also ran cooler than the MAX.
In that same test the 1.7Ah PS cut 27′ and ran much hotter. See image below.
In another test the 3.5Ah PS cut 45′ of 2x lumber, compared to the 5Ah Max’s 53′. Both batteries finished at the same temperature.
Longer Lifespan
DeWalt first marketed PowerStack batteries as having twice the lifespan of 20V Max packs. Now they say “longer lifespan,” likely meaning more charge cycles before capacity fade.
This probably means, for example, if a 5Ah Max drops to 80% capacity after ~300 cycles (roughly my experience), a 5Ah PS should hit 80% after ~600. This uses the standard lithium-ion metric: cycles to noticeable fade.
I know from hands-on experience that heat is the enemy of runtime and they say heat degrades a batteries recharge capacity, which sounds reasonable to me. In our tests we’ve noted PowerStacks create less heat per work vs Max batteries so it seems like a good bet that the longer lifespan claim is legit.
Will casual users—who don’t recharge daily or push heavy workloads—notice the difference? Probably not much. For light use, most degradation comes from calendar aging (time on the shelf), not cycles.
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3.5 Ah PowerStack
5 Ah PowerStack
5 Ah MAX
Bottom Line
For small 20V tools like wrenches, I think the 1.7 Ah PowerStack is a good fit. Otherwise, not a fan. For more power and work capacity the 5Ah PS seems like the best bet if you can find them on sale and don’t mind the larger footprint.
I do mind, and find I grab for a regular 5Ah Max more often than I grab for the 5Ah PowerStack. For that reason I think I’ll stick with teh 5Ah Max and 9Ah FlexVolts for now.
Let us know your thoughts in the comments and check out this review to see these bad boys in action. See ya!
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