Which battery lasts longer per charge?

The 8 Ah DCB2108, at roughly double the capacity of the 4.0Ah pack. Expect close to twice the runtime in the same tool under the same load.

Is the 8 Ah battery worth the extra money?

Yes for saws, grinders and other high-draw tools where runtime and power matter. For a drill or impact driver used in short bursts, the 4.0Ah pack is lighter and usually cheaper.

Will both fit my existing DeWalt 20V MAX tools and charger?

Yes. Both are 20V MAX packs and work with all 20V MAX tools and chargers. Neither ships with a charger.

Which is better for overhead work?

The 4.0Ah pack. At about 1.4 lb versus 2.2 lb, it keeps a drill or driver balanced when working above your head.

Do both have a charge indicator?

Yes. The 8 Ah has an LED state-of-charge indicator and the 4.0Ah has a 3-light LED fuel gauge.

How long do they take to charge?

Both are listed at about 60 minutes on a 20V MAX charger, though the 8 Ah may take longer on slower chargers.

DeWalt DCB2108 20V MAX XR POWERPACK 8 Ah Battery vs DEWALT 20V MAX XR Premium Lithium-Ion 4.0Ah Battery Pack

Buy the 8 Ah DCB2108 if you run high-draw tools like circular saws, grinders or a string trimmer and want the longest runtime per charge. Buy the 4.0Ah pack if you want a lighter battery for drills, impact drivers and overhead work, or want a spare at lower cost. The 8 Ah has tracked around $129.90 to $130.00 since late October 2026, while the 4.0Ah pack has swung from $149.00 down to $57.49, so the 4.0Ah is often the cheaper buy per pack but delivers roughly half the capacity.

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