Replacement Battery for Greenworks Battery (40.0V 4.0Ah)

What It Is

This is a 40.0V, 4.0Ah lithium-ion replacement battery for Greenworks cordless lawn mowers, trimmers, blowers, and other 40V G-Max tools. It powers mowers with 16- to 21-inch decks and other outdoor equipment that uses the same G-Max battery platform.

Fitment & Compatibility

Before buying, verify your tool uses the Greenworks 40V G-Max battery system (not the 24V, 60V, or 80V lines). Check your mower’s model number—common compatible series include 25022, 25142, 25262, and 25322, but not all 40V models share the same battery shape. Also confirm the battery compartment dimensions: this 4.0Ah pack is slightly taller than the 2.0Ah version, so measure your battery slot depth (approx. 6.5 x 4 x 4 inches) to ensure it fits. This is an OEM replacement, not an aftermarket knockoff, so it should match original fit exactly.

Key Things to Know

• Compatibility is not universal – Some newer Greenworks 40V tools (like the “Twin Force” mowers) use a different battery shape. Always cross-reference your tool’s model number with Greenworks’ compatibility list.
• Installation is tool-free – Slide the battery into the mower’s compartment until it clicks, then press the release tab to remove. No wiring or modifications needed.
• Charge time – With the standard Greenworks 40V charger (sold separately if you don’t have one), this 4.0Ah battery takes about 2–3 hours to fully charge. Check your charger’s output rating (typically 2A) for accurate time.
• Performance note – A 4.0Ah battery provides roughly 40–50 minutes of mowing on a 20-inch deck, depending on grass thickness. For larger yards (over 1/4 acre), you’ll likely need two batteries to finish without recharging.

Should You Buy It

If you own a compatible Greenworks 40V G-Max mower or tool and need a reliable, direct OEM replacement, this battery delivers solid runtime and build quality at a fair price. It’s a better choice than cheap aftermarket options that may have poor cell quality or shorter life. However, if you have a newer Greenworks model (post-2022) or a non-G-Max system, verify fitment first—otherwise you’ll waste $100.