Milwaukee M12 REDLITHIUM 2.0Ah Battery (2-Pack) & Charger Kit vs RYOBI 40V Lithium-Ion 4Ah High Capacity Battery
Head-to-head spec comparison to help you pick the right battery for your needs.
Deciding between a genuine pack and a cheaper aftermarket one? Read our honest genuine vs aftermarket batteries guide.Read the guide →
Spec Winner
Milwaukee M12 REDLITHIUM 2.0Ah Battery (2-Pack) & Charger Kit
Wins on 3 of 4 spec categories
Spec-by-Spec Comparison
| Spec | Milwaukee M12 REDLITHIUM 2.0Ah Battery (2-Pack) & Charger Kit | RYOBI 40V Lithium-Ion 4Ah High Capacity Battery |
|---|---|---|
| Platform | M12 | 40V |
| Voltage | 12V MAX | 40V MAX |
| Capacity | 2 Ah | 4 Ah |
| Type | compact | high-output |
| Genuine OEM | Yes | Yes |
| Fuel Gauge | No | No |
| Warranty | 5 years | 3 years |
| Price | $59.89 | $104.99 |
| Rating | 8.5/10 | 8.4/10 |
| Buy on Amazon | Buy on Amazon |
Pros & Cons
Milwaukee M12 REDLITHIUM 2.0Ah Battery (2-Pack) & Charger Kit
Pros
- Genuine Milwaukee M12 packs backed by Milwaukee's 5-year warranty
- Kit includes two batteries plus a charger — a solid starter bundle for the M12 platform
- Compact 2.0Ah cells keep M12 tools light for one-handed work
- Straightforward drop-in fit for any M12 tool
Cons
- 2.0Ah per pack is on the lower end for longer-runtime jobs
- Only compatible with M12 tools, not M18
- No fuel gauge on these compact cells
RYOBI 40V Lithium-Ion 4Ah High Capacity Battery
Pros
- Genuine RYOBI 40V pack backed by RYOBI's 3-year warranty
- 4Ah capacity suits RYOBI's outdoor power equipment lineup — mowers, trimmers, blowers
- Fits the full RYOBI 40V platform
Cons
- Listed as low stock at the time of this write-up — availability can be inconsistent
- Mid-range price relative to smaller-capacity 40V packs
- Only compatible with 40V tools, not ONE+ 18V
Our Verdicts
Milwaukee M12 REDLITHIUM 2.0Ah Battery (2-Pack) & Charger Kit
A genuine Milwaukee M12 two-battery-and-charger kit is the straightforward, warranty-backed way to get started or restock on the M12 platform — not the highest capacity, but the safest default.
RYOBI 40V Lithium-Ion 4Ah High Capacity Battery
A genuine RYOBI 40V pack for the outdoor-tool side of the lineup — solid capacity for mowers and trimmers, though stock availability has been inconsistent.
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