Milwaukee M12 and M18 are separate tool battery systems. The 48-59-1812 charger accepts both, but that charger feature does not make the packs interchangeable in tools.
Identify the system on each product
The 48-11-1850 is an M18 battery. The 2953-20 impact driver is an M18 tool. Their relationship can be checked within Milwaukee’s stated M18 system.
Check charger behavior
Milwaukee says the 48-59-1812 multi-voltage charger accepts both M12 and M18 batteries and charges them sequentially. A dual charger is a manufacturer-designed exception for charging.
Avoid a tool-system leap
An M12 pack is not thereby approved for a 2953-20 M18 impact driver. The charger’s multiple slots cannot be used as a proxy for tool compatibility.
Next step
Official sources
These source records were reviewed as of 2026-10-30; access methods differ. Open the latest manufacturer manual for your exact type, region and revision before use.
- Milwaukee Tool — 48-59-1812 product page48-59-1812 accepts M12 and M18 batteries sequentially · curated_primary · Checked 2026-10-30
- Milwaukee Tool — 48-11-1850 product page48-11-1850 M18 5.0Ah identity · curated_primary · Checked 2026-10-30
- Milwaukee Tool — 2953-20 product page2953-20 M18 tool and all M18 batteries · curated_primary · Checked 2026-10-30