1 Pack 6.0Ah Lithium-ion Replacement for Kobalt 40V Battery Compatible with KPM1040A-03, KM-1640-06, KM 4040-06,Cordless Power Tool Battery

What It Is

This is a 6.0Ah lithium-ion battery pack designed to power Kobalt 40V cordless lawn mowers, string trimmers, blowers, and other 40V outdoor power tools. It replaces the original Kobalt 40V battery (often 2.5Ah–5.0Ah) and provides longer runtime for larger yards or heavy-draw tools.

Fitment & Compatibility

Check your tool’s voltage and platform: This battery works only with Kobalt 40V (not 80V or 24V) tools. It is compatible with models like KPM1040A-03 (mower), KM-1640-06 (trimmer), and KM 4040-06 (blower), plus most other Kobalt 40V tools sold under the same platform.

Measure the battery compartment: The 6.0Ah pack is physically larger than the stock 2.5Ah or 4.0Ah batteries. Before buying, confirm the battery slot in your mower or tool can accommodate the extra height and width. Some older or compact tools may not fit.

OEM vs. aftermarket: This is a third-party replacement, not a Kobalt OEM battery. It will charge on your Kobalt 40V charger, but performance and lifespan may vary. Check that the terminal layout matches your charger (most Kobalt 40V chargers use the same three-slot pattern).

Compatibility note: If your tool uses a slide-in battery (most Kobalt 40V tools do), this should work. Avoid if your tool uses a different battery platform (e.g., Kobalt 80V or 24V).

Key Things to Know

• Installation is drop-in: No tools required. Slide the battery into the tool’s battery compartment until it clicks. To remove, press the release button and slide out.
• Quality variance: Aftermarket batteries may have slightly lower cycle life or capacity than OEM. Check reviews for reports of early failure or swelling. This pack has a 4.5 rating, but individual experiences vary.
• Charging time: Expect 2–4 hours to fully charge from empty using a standard Kobalt 40V charger. The 6.0Ah capacity takes longer than smaller packs.
• Storage & care: Store at room temperature, avoid full discharge, and recharge every 3–6 months if not in use. Do not leave on the charger for extended periods.

Should You Buy It

If you own a Kobalt 40V tool and need more runtime than the stock battery offers, this 6.0Ah pack is a budget-friendly upgrade. It’s best for medium-to-large yards (up to 1/3 acre with a mower) or for users who want to swap less often. Avoid if you require OEM reliability or if your tool’s battery compartment is tight—measure first.