Quick Specs
What Battery Does the Milwaukee 2731-20 Use?
The Milwaukee 2731-20 M18 FUEL 7-1/4″ Circular Saw runs on the Milwaukee M18 18V battery platform. Any Milwaukee M18 REDLITHIUM battery will power this tool, though high-capacity batteries are strongly recommended for cutting applications.
About the Milwaukee 2731-20
The Milwaukee 2731-20 is a full-size 7-1/4″ circular saw powered by a POWERSTATE brushless motor that delivers 5,800 RPM. It cuts 2-1/2″ deep at 90° and 1-3/4″ at 45°, matching the performance of many corded saws. With a magnesium upper and lower guards for durability and an aircraft aluminum shoe for accuracy, it’s built for professional framing and general construction cutting.
Compatible Batteries
| Battery Model | Capacity | Weight | Best For |
|---|---|---|---|
| 48-11-1815 | 1.5Ah | 0.75 lb | Not recommended for this tool |
| 48-11-1820 | 2.0Ah | 0.81 lb | Not recommended for this tool |
| 48-11-1830 | 3.0Ah | 1.06 lb | A few cuts only |
| 48-11-1840 | 4.0Ah | 1.25 lb | Light cutting sessions |
| 48-11-1850 | 5.0Ah | 1.5 lb | Recommended for regular use |
| 48-11-1860 | 6.0Ah | 1.56 lb | Best for extended cutting and framing |
Recommended Circular Saw Blades
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Recommended Battery
For the 2731-20, the 48-11-1860 (6.0Ah) High Output battery is the best choice. Circular saws are among the most power-hungry cordless tools, and the 6.0Ah pack provides both the sustained current needed for clean cuts through lumber and enough capacity to make meaningful progress on framing jobs before needing a swap.
Minimum Battery
The 48-11-1840 (4.0Ah) is the practical minimum for the 2731-20. While a 3.0Ah battery will physically work, you’ll only get a handful of cuts before the battery is depleted. For anything beyond occasional trim cuts, use a 5.0Ah or larger pack.
Battery Compatibility Notes
- All M18 REDLITHIUM batteries are compatible, but High Output packs are strongly recommended for circular saws
- High Output batteries run cooler and deliver more sustained power during continuous cutting
- M18 batteries are NOT compatible with M12 tools or older V18 tools
- Keep two fully charged high-capacity batteries on hand for framing jobs — circular saws drain batteries quickly
Related Resources
- Milwaukee 48-11-1850 Battery Details
- Milwaukee 48-11-1860 Battery Details
- Milwaukee M18 Battery Compatibility Guide
- Battery Compatibility FAQ
Battery sizing, runtime & troubleshooting
Recommended pack: A circular saw is a top-tier draw. Run a 5.0Ah XC as a minimum and a HIGH OUTPUT pack for ripping or sustained cutting. Compact packs sag and cut out.
Compatibility caveats: Fits all M18; this model is discontinued but genuine. HIGH OUTPUT benefit is inference, not a stated requirement.
If it won’t start or cuts out: Blade slowing or cut-out during a rip means the pack is too small or hot — fit a 5.0Ah+.
Runtime: Milwaukee quotes up to about 300 cuts per charge on a 5.0Ah pack (in their test material).
Versus the adjacent model: Shares the grinder’s and rotary hammer’s appetite — give it your largest, highest-output pack.
Where to Buy
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