2-Pack 40V 4.0Ah Battery Replacement for Greenworks 40V Battery and Charger Kit, Compatible with Greenworks 40 Volt G-MAX Cordless Power Tools

What It Is

This is a 2-pack of 40V 4.0Ah lithium-ion batteries designed as a replacement for Greenworks 40V G-MAX cordless tools, including lawn mowers, string trimmers, blowers, and chainsaws. Each battery delivers 144Wh of energy, suitable for medium-duty yard work.

Fitment & Compatibility

• Voltage & Platform: Must be 40V G-MAX (not 60V or 80V). Check your tool’s battery port for the G-MAX logo.
• Model Fit: Compatible with Greenworks 40V G-MAX tools (e.g., mowers 25302, 25312, 25322; trimmers 21262; blowers 24252). Not for non-G-MAX Greenworks 40V batteries (e.g., older “twin-port” or “USB” models).
• OEM vs Aftermarket: This is an OEM Greenworks part, so fitment and charging are identical to original batteries. No adapter needed.
• Physical Check: Each battery measures 5.5 x 3.5 x 4.5 inches, weight ~1.5 lbs. Ensure your tool’s battery slot is not obstructed by debris or damage.

Key Things to Know

• Charging: Use only Greenworks 40V G-MAX chargers (e.g., 2901402, 2902302). Third-party chargers may damage the battery or cause slower charging.
• Installation: No tools needed—slide battery into tool until it clicks. If it doesn’t lock, check for dirt on contacts or a bent latch.
• Performance: 4.0Ah gives ~30–45 minutes runtime on a 20-inch mower (average cut). Real-world runtime varies with grass thickness and tool load.
• Common Gotcha: These batteries have a low-voltage cutoff—if your tool suddenly stops mid-use, recharge immediately. Storing empty can permanently kill the cells.

Should You Buy It

Buy this if you own a Greenworks 40V G-MAX tool and need a reliable OEM replacement with consistent fit and charging. It’s a solid choice for daily use, but the 3.8 rating suggests some users report early capacity fade—consider a 5.0Ah upgrade if you need longer runtime. Avoid if you don’t have a G-MAX charger or if your tool is from a different Greenworks voltage platform.