Milwaukee M18 REDLITHIUM 5.0Ah Battery (48-11-1850) 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-by-Spec Comparison
| Spec | Milwaukee M18 REDLITHIUM 5.0Ah Battery (48-11-1850) | RYOBI 40V Lithium-Ion 4Ah High Capacity Battery |
|---|---|---|
| Platform | M18 | 40V |
| Voltage | 18V | 40V MAX |
| Capacity | 5 Ah | 4 Ah |
| Type | high-output | high-output |
| Genuine OEM | Yes | Yes |
| Fuel Gauge | No | No |
| Warranty | 5 years | 3 years |
| Price | $67.99 | $104.99 |
| Rating | 8.8/10 | 8.4/10 |
| Buy on Amazon | Buy on Amazon |
Pros & Cons
Milwaukee M18 REDLITHIUM 5.0Ah Battery (48-11-1850)
Pros
- Genuine Milwaukee M18 pack backed by Milwaukee's 5-year warranty
- Drops straight into any M18 tool — no adapters, no guesswork
- 5.0Ah capacity gives solid runtime for daily-use M18 tools
- REDLITHIUM cell design is Milwaukee's own in-house spec
Cons
- No onboard fuel gauge — can't check remaining charge at a glance
- Costs more than aftermarket M18-compatible packs
- Only fits the M18 platform, not M12 or other brands
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 M18 REDLITHIUM 5.0Ah Battery (48-11-1850)
A genuine Milwaukee M18 pack is the safe first buy for anyone standardized on the M18 platform — real Milwaukee chemistry and the full manufacturer warranty, not a third-party guess.
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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