Short answer: DeWalt does not sell a single “20V MAX battery” — it sells at least nine different capacities across three families (12V MAX, 20V MAX, and FlexVolt), from a 3Ah 12V MAX pack up to a 15Ah FlexVolt pack. DeWalt’s own product pages confirm its 20V MAX XR POWERSTACK batteries are “compatible with 20V MAX tools,” but no page reviewed for this guide states that every capacity is interchangeable in every 20V MAX tool beyond that general platform statement.
Why DeWalt sells so many battery capacities
DeWalt’s 20V MAX platform page states the system spans “300+ 20V products and growing” — a large, shared tool pool is exactly why a single battery size wouldn’t fit every use case. A compact 4Ah pack keeps a drill light for overhead work; a 10Ah pack trades weight for runtime on a table saw or a long job. DeWalt’s own battery landing page lists 20V MAX batteries at 4Ah, 5Ah, 6Ah, 8Ah and 10Ah, plus a separate 20V MAX XR line at 3.5Ah, 5Ah (an oil-resistant variant) and 8Ah.
The full capacity lineup, by family
| Family | Capacities DeWalt lists |
|---|---|
| 12V MAX | 3Ah |
| 20V MAX (standard) | 4Ah, 5Ah, 6Ah, 8Ah, 10Ah |
| 20V MAX XR | 3.5Ah, 5Ah (oil-resistant), 8Ah |
| FlexVolt (20V/60V MAX) | 6Ah, 9Ah, 12Ah, 15Ah |
Note that 12V MAX is its own separate battery family, not a lower capacity within 20V MAX — as covered in this site’s DeWalt 18V-vs-20V-MAX guide, 12V MAX batteries do not power 20V MAX or FlexVolt tools.
What “compatible with 20V MAX tools” actually covers
The clearest compatibility statement found across the pages reviewed for this guide is on DeWalt’s own 20V MAX XR POWERSTACK Compact Battery Kit page: “compatible with 20V MAX tools.” That page also qualifies its headline “50% more power” claim as measured “vs. DEWALT DCB203 battery, not in application” — a lab comparison against one specific older battery, not a guaranteed real-world jobsite gain. DeWalt states the same voltage disclosure used throughout this site’s other DeWalt guides: maximum initial voltage is 20V, nominal voltage is 18V.
A charger accessory that isn’t just a charger: DCB1800B
DeWalt’s DCB1800B is a portable power station that runs on four 20V MAX batteries (FlexVolt included) at once and can charge multiple batteries simultaneously. It ships “tool only” — no battery or charger included — and DeWalt recommends four 3Ah DCB200 batteries or higher-Ah packs “for best results.” It’s a genuinely different accessory category from a wall charger: instead of charging one or two batteries from mains power, it turns a set of batteries the owner already has into a portable power source.
What this guide does not claim
DeWalt’s pages do not state that every listed capacity fits every 20V MAX tool without exception, so this guide doesn’t either — “compatible with 20V MAX tools” is the general platform statement DeWalt itself publishes, and that’s the level of claim repeated here. Runtime-per-Ah in any specific tool is not stated in any source checked and is not estimated in this guide.
How this was checked
Facts on this page are drawn from DeWalt’s own battery landing page, its 20V MAX XR battery platform page, the POWERSTACK compact battery kit product page, the DCB1800B power station product page, the 60V MAX system page (for the 15Ah FlexVolt figure), and the 20V MAX platform page (for the “300+ products” figure).
Sources checked: 2026-08-06. A new review date will only be set after the linked pages are re-checked.