Milwaukee’s FORGE batteries are its premium M18 battery line. Here’s everything you need to know about the FORGE lineup and whether it’s worth upgrading.
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What Is Milwaukee FORGE?
FORGE is Milwaukee’s premium battery line within the M18 system. Milwaukee UK lists FORGE packs including the M18 FB8 (8.0Ah) and M18 FB12 (12.0Ah), and Milwaukee EU the M18 FB6 (6.0Ah). We have not confirmed the cell design Milwaukee uses in them.
Milwaukee sells FORGE alongside its HIGH OUTPUT packs, aimed at professional tradespeople who push their tools hard.
FORGE Battery Lineup
M18 FORGE 6.0Ah (M18 FB6):
Capacity: 6.0Ah
Weight: 1.03 kg (Milwaukee EU)
Best for: All-day use on high-drain tools such as rotary hammers, grinders and circular saws
Charging: Milwaukee US says a FORGE XC6.0 reaches 80% in 15 minutes on its 48-59-1815 Dual Bay Super Charger
M18 FORGE 8.0Ah (M18 FB8):
Capacity: 8.0Ah
Weight: 1.08 kg (Milwaukee UK)
Best for: Long runtime for sustained high-demand work
Note: the 48-11-1880 is a different pack, Milwaukee’s HIGH OUTPUT XC8.0
M18 FORGE 12.0Ah (M18 FB12):
Capacity: 12.0Ah
Weight: 1.51 kg (Milwaukee UK)
Best for: The longest runtime of these FORGE packs
Charging: Milwaukee UK says 35 minutes to 80% and 45 minutes to full on its M18 dual bay super charger
FORGE vs REDLITHIUM HIGH OUTPUT vs Standard REDLITHIUM
Milwaukee now has three tiers of M18 battery:
Standard REDLITHIUM — The baseline. Reliable, affordable, good for light to moderate use.
REDLITHIUM HIGH OUTPUT — Milwaukee says its HIGH OUTPUT XC8.0 and HD12.0 packs give 50% more power and run 50% cooler. The mid-range option.
FORGE — Milwaukee’s premium tier. On Milwaukee’s US charge-time chart a FORGE XC6.0 charges faster than a HIGH OUTPUT XC6.0 (25 against 35 minutes on a super charger).
Are FORGE Batteries Compatible with Existing M18 Tools?
Yes. Milwaukee says all M18 batteries are compatible with M18 tools and chargers, and FORGE packs are M18 batteries. Your existing M18 batteries also continue to work in all your M18 tools — FORGE is an additional option, not a replacement platform.
Is FORGE Worth the Upgrade?
Upgrade to FORGE if:
- You’re a professional using M18 FUEL tools daily and want the best possible performance
- You use high-drain tools (grinders, rotary hammers, circular saws) and notice performance drop-off with current batteries
- You want batteries that maintain their capacity longer over years of use
Stick with HIGH OUTPUT or standard REDLITHIUM if:
- You’re a DIYer or light-use professional — the performance gains won’t be noticeable on drills and impact drivers
- You need batteries in bulk and want to keep costs manageable
- Your current HIGH OUTPUT batteries are still performing well
Where to Buy
Search for Milwaukee FORGE batteries on Amazon
For a full comparison of every M18 battery option, see our guide: Every Milwaukee M18 Battery Compared.
Related Guides
- Every Milwaukee M18 Battery Compared
- Every Milwaukee M18 Tool and Which Batteries Fit
- Milwaukee M18 Charger Compatibility Guide
- Milwaukee M18 vs M18 FUEL
Video Guide
FORGE vs Standard M18 Batteries in Practice
Milwaukee markets FORGE as its highest-performance M18 battery line. We have not tested FORGE against HIGH OUTPUT packs and have no maker figures for the cells it uses.
We have no maker data comparing sustained power under load between FORGE and HIGH OUTPUT packs of the same capacity, so we make no claim about cut speed or work per charge.
On Milwaukee’s US charge-time chart, a FORGE XC6.0 reaches full charge in 25 minutes on a super charger, 62 on a rapid charger and 115 on a standard charger, against 35, 65 and 123 minutes for a HIGH OUTPUT XC6.0.
Should You Upgrade to FORGE?
Upgrade if: you use M18 FUEL tools professionally for demanding work such as concrete cutting, sustained grinding or heavy framing, and faster charging on a super charger matters to you.
Wait if: You primarily use M18 tools for standard drilling, driving, and light cutting tasks. Current High Output and XC batteries deliver excellent performance for these applications, and the FORGE premium is harder to justify for lighter-duty use.
All FORGE batteries are M18 batteries, and Milwaukee says all M18 batteries are compatible with M18 tools and chargers. You do not need new tools to use FORGE batteries.
What makes Milwaukee FORGE batteries different?
Milwaukee sells FORGE as its premium M18 battery tier. On its US charge-time chart a FORGE XC6.0 charges faster than a HIGH OUTPUT XC6.0 (25 against 35 minutes on a super charger). We have no maker figures for its cell chemistry or sustained output.
Are FORGE batteries compatible with older M18 tools?
Yes. Milwaukee says all M18 batteries are compatible with M18 tools and chargers, and FORGE packs are M18 batteries.
Is FORGE replacing REDLITHIUM HIGH OUTPUT?
FORGE is the newest tier in Milwaukee’s battery lineup and sits above HIGH OUTPUT. Milwaukee has not announced discontinuation of HIGH OUTPUT batteries. For most users, HIGH OUTPUT batteries remain an excellent choice. FORGE is targeted at professionals with the most demanding applications who need every bit of extra performance.
Genuine batteries, chargers and kits for this platform
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Before you buy: check that the size, fitting/bore and maximum-rated speed marked on the accessory match what your tool’s manual specifies. We have not physically tested these products; listings are compiled from published specifications. These are affiliate links.
Frequently Asked Questions
No single brand wins across every category. Your best choice depends on which tools you already own — switching platforms is rarely worth the cost.
Is Milwaukee FORGE worth the extra cost?
It can be for professionals using high-demand tools daily; Milwaukee markets FORGE as its premium tier, but we have not compared power or life ourselves. For occasional users, standard M18 batteries offer better value.
Do FORGE batteries work in all M18 tools?
Yes. FORGE batteries are fully backward-compatible with all Milwaukee M18 tools.
How long do FORGE batteries last?
We have no Milwaukee figure for FORGE cycle life in our sources, and we have not tested one. Lithium-ion packs lose capacity with use and age.
How we compile this guide
We cross-reference compatibility details against manufacturer specifications where available, official tool manuals, and the physical standards that govern fitment (bore sizes, arbor diameters, voltage platforms, connector types). We prioritise primary sources over retailer listings, flag anything we can’t confirm, and re-verify the data on a regular cycle. Where we give a buying recommendation, we tell you the reasoning — not just the link. More on our method →
