PENGJBATTER 2 Packs 40V 3Ah Battery Compatible for Worx 40V Battery WA3580 & 40 Volt Cordless Tools WG180 WG280 WG380 WG580 & Charger WA3747 WA3877 (Not Fit 2x20V Tools & Nitro Series WG185)

What It Is

This is a third-party 40V 3Ah lithium-ion battery pack, sold as a two-pack, designed to replace the Worx WA3580 OEM battery. It’s meant for Worx 40V cordless lawn mowers, string trimmers, blowers, and other 40V tools in the WG series.

Fitment & Compatibility

• Works with: Worx 40V tools from the WG180, WG280, WG380, WG580 series, plus chargers WA3747 and WA3877.
• Does NOT fit: Any 2x20V (40V dual-port) tools or the Nitro Series WG185. Check your tool’s voltage rating on the battery label—if it says “40V Max” on a single port, this fits.
• Physical check: The battery has the same slide-and-lock form factor as the WA3580. Measure your battery compartment: 5.5" L x 3.5" W x 2.5" H roughly. If your original battery slides in from the back, this should match.
• OEM vs. aftermarket: This is a non-Worx battery. It may not have the same BMS (battery management system) protection, so avoid using it with high-draw tools like the WG185 Nitro.

Key Things to Know

• Quality concerns: At 3.8 stars from 61 reviews, some users report shorter runtime or earlier failure compared to original Worx batteries. Expect about 30-40 minutes of mowing on a 3Ah pack, depending on grass conditions.
• Installation: No tools needed—slide into the tool’s battery port until it clicks. Charge with your existing Worx 40V charger (WA3747 or WA3877). Do not force if it doesn’t slide easily.
• Common gotcha: If your tool is a 2x20V model (uses two 20V batteries at once), this 40V pack will not work. Look for “40V” on the tool body, not “2x20V.”
• Charging note: The battery may take slightly longer to charge on a Worx charger because third-party cells can have different internal resistance. Avoid leaving it on the charger after full charge.

Should You Buy It

Buy this if you need a budget-friendly backup or spare battery for light-duty 40V Worx tools (like a trimmer or blower) and don’t mind slightly shorter lifespan than OEM. Skip it if you rely on your mower for heavy weekly cuts or own a Nitro Series tool—stick with genuine Worx WA3580 for reliability and warranty protection.