40V 3.5Ah Battery for Worx 40V Battery Replacement, Compatible with Worx Batería WA3580 WG180 WG280 WG380 WG580 (Not for 2x20V Tools & Nitro Series WG185 Tools)

What It Is

This is a 40V 3.5Ah lithium-ion battery designed as a direct replacement for Worx 40V cordless lawn mowers, trimmers, blowers, and other outdoor power tools. It powers mid-duty tasks like mowing a ¼-acre lawn or running a string trimmer for 30-45 minutes on a single charge.

Fitment & Compatibility

Check model numbers – This battery fits Worx models WA3580, WG180, WG280, WG380, and WG580. It does not work with 2x20V tools (dual battery systems) or Nitro Series WG185 tools.
Measure battery compartment – The battery dimensions are 5.5" x 3.5" x 3.5". Verify your tool’s battery slot is deep and wide enough (most Worx 40V tools use the same slide-in design).
OEM vs aftermarket – This is a non-OEM replacement. It uses the same voltage and connector pinout as genuine Worx batteries, but may have slightly different plastic molding. Test fit before fully sliding in.
Charger compatibility – Works with any Worx 40V charger (e.g., WA3742, WA3880). Do not use with 20V-only chargers.

Key Things to Know

• Installation – Slide battery into tool until it clicks. No tools needed. If it doesn’t click, check for debris or molding flash on the battery rails.
• Performance – 3.5Ah provides ~20% more runtime than a standard 2.5Ah Worx battery. Expect ~35-45 minutes of mowing (depending on grass thickness).
• Quality – This is a third-party battery. It may lack over-discharge protection found in OEM batteries. Avoid draining it below 20% to extend lifespan.
• Storage – Store at 40-80% charge in a cool, dry place. Freezing or heat above 120°F can permanently reduce capacity.

Should You Buy It

Buy this if you already own a compatible Worx 40V tool and need a spare or replacement at a lower price than OEM. Skip it if you use 2x20V tools, Nitro WG185 tools, or need maximum reliability for heavy daily use—OEM batteries offer better warranty and safety circuits.