40V 6.0Ah Replacement for Kobalt 40V Battery MAX KM 2041B-06, KPM1040A-03, KM-1640-06, KM 4040-06, Fit for Kobalt Battery Charger (Blue)

What It Is

This is a 40V 6.0Ah lithium-ion replacement battery for Kobalt 40V MAX outdoor power equipment. It powers cordless lawn mowers, string trimmers, blowers, and hedge trimmers that use the blue Kobalt 40V battery platform.

Fitment & Compatibility

Before buying, confirm your tool uses the Kobalt 40V MAX (blue) battery platform. This battery fits models including KM 2041B-06, KPM1040A-03, KM-1640-06, and KM 4040-06. It also works with any Kobalt 40V charger that accepts the blue slide-on battery (not the older red or yellow platforms). Check the physical shape – this is the slide-mount style, not the older push-button or top-mount types. Measure your existing battery: this one is roughly 5.5” x 3” x 4.5”. If your tool uses a different voltage (e.g., 80V or 24V) or a different color platform (red, yellow, green), it will not work.

Key Things to Know

• Aftermarket, not OEM – This is a third-party replacement, not made by Kobalt. Performance and longevity may vary from the original.
• 6.0Ah capacity – Higher than the standard 2.0Ah or 4.0Ah packs, so runtime is longer, but it’s also heavier. Expect ~30–50% more runtime than a 4.0Ah battery depending on load.
• Installation is tool-free – Slides onto the tool or charger just like the original. No wiring or modifications needed.
• Common gotcha – Some users report the battery doesn’t fully seat on older Kobalt tools due to slight molding differences. If your tool is more than 5 years old, test fitment before fully relying on it.

Should You Buy It

Buy this if you need an affordable spare or upgrade for your Kobalt 40V blue-platform tools and don’t mind an aftermarket battery. It’s a good value for the higher capacity, but if you demand OEM reliability or have an older tool with tight battery fit, stick with Kobalt’s own battery.