The M18 5.0Ah REDLITHIUM battery features superior pack construction, electronics, and performance to deliver more work per charge and more work over the life of the pack than any battery on the market.M18 5.0Ah REDLITHIUM battery features an advanced design, protecting the pack against harsh jobsite environments. This protection routes water away from the electronics and out of the battery pack, extends run-time and life by minimising heat, and prevents pack failures from vibration or drops. This unique to Milwaukee design also allows the battery to operate in extreme cold weather conditions (below 0 degreeF/-18 degreeC).Managed by Milwaukees exclusive REDLINK Intelligence, the battery features overload protection to prevent you from damaging your cordless power tools in heavy-duty situations, while the discharge protection prevents cell damage. It also provides full system compatibility with 150+ M18 cordless solutions. Upgrade to the M18 5.0Ah REDLITHIUM battery to instantly increase the run-time and durability of your M18 cordless tools.