48-11-2440 M12 4.0 Ah battery

The 48-11-2440 is Lithium Ion battery pack for the M1 battery system manufactured by Milwaukee. Milwaukee calls it M12 Red Lithium XC 4.0.

Milwaukee claims the battery pack will work in cold climates with temperatures below 0°F / -18°C but does not specify a minimum temperature on the website or manual.

The battery should be charged in an ambient temperature of 40°F / 5°C  to 105°F / 40°C and the battery should not be stored in temperatures higher than 120°F / 50°C

The battery pack contains electronics that prevent damage from overheating or discharging too much.

In 2021 this battery was not listed on Milwaukee USA's website when filtering for M12 batteries but can be found through the tool pages for kits that include the battery.

Milwaukee does not specify the weight on their website.

Exterior

The battery packs contains three cylindrical 18650 cells that are grouped together upright so that the battery pack can fit inside a handle of a power tool.

The battery pack has a red plastic casing with recessed electrical contacts on top. On the bottom is a black plastic cap with latches on both sides to retain the battery when inserted in a tool.