Milwaukee Red Lithium, 12V 4.0Ah Battery Pack

Voltage: 12V (nominal); Capacity: 4Ah; Chemistry: RedLithium Li-Ion; Form factor: compact and lightweight design to fit the M12 tool family.

Ensure the tool is off. Align the battery contacts with the tool’s contacts, slide the battery into the grip until you hear a click, and verify the battery is secured before using the tool. To remove, press the release latch and pull the battery away from the tool.

Use any Milwaukee M12 charger to recharge the battery. Attach the battery to the charger and allow it to charge until the indicator shows full. Charging time varies by charger model and ambient temperature, but it is generally under an hour on standard fast-charging setups.

Ideal for longer-running tasks with M12 cordless tools, such as drilling, driving, grinding, and cutting jobs where extended runtime and portability are beneficial for professionals and DIY enthusiasts alike.

Do not crush, puncture, or expose the battery to fire or water. Avoid storage or operation in extreme temperatures beyond the recommended range. Use only approved Milwaukee chargers, keep away from metal objects to prevent short circuits, and dispose of or recycle per local regulations.

Monitor performance during use; a noticeable drop in runtime, frequent overheating, or reduced power indicates the battery may be nearing end of life. Use the tool's indicators or the battery’s charge gauge to assess remaining capacity, and avoid using visibly swollen or damaged packs.

- Compared to M12B2 (2Ah): M12B4 offers longer runtime with a higher capacity, at the cost of slightly more weight. See: https://fepy.com/product/milwaukee-m12b2-redlithium-12v-2ah-battery - Compared to M12B6 (6Ah): M12B6 provides even longer runtime but is heavier and bulkier. See: https://fepy.com/product/milwaukee-m12b6-redlithium-12v-6ah-battery - Compared to M12B8 (8Ah): M12B8 delivers the maximum runtime among common M12 packs but is the heaviest. See: https://fepy.com/product/milwaukee-m12b8-redlithium-12v-8ah-battery

Store in a cool, dry place away from direct heat. For long-term storage, keep the battery at a roughly modest charge (not fully discharged or fully charged). Check the battery and charger periodically and avoid leaving the battery in extreme temperatures or on metal surfaces.

If you’re not satisfied, you can follow Fepy’s standard return process within the applicable window. Please ensure the battery is in its original packaging and in resalable condition, and initiate the return through your account or customer support as per Fepy’s guidance.

Use the battery within the recommended temperature range, avoid deep discharges, and charge promptly after use. For high-demand work, consider a higher-capacity option (e.g., M12B6 or M12B8) if runtime is critical. Keep tools and batteries clean, and store in a climate-controlled area to preserve battery health.