2 Packs 40V 3.5Ah Replacement for Worx 40V Battery WA3580 Compatible with Worx 40 Volt Cordless Power Tools WG180 WG280 WG380 WG580 WG776 & Chargers WA3747 WA3877 (Not fit 2x20V & Nitro Series Tools)

What It Is

This is a two-pack of 40V 3.5Ah aftermarket lithium-ion batteries designed to replace the Worx WA3580. They power Worx 40V cordless tools like mowers (WG180, WG280, WG380, WG580, WG776) and charge with Worx WA3747 or WA3877 chargers. The 3.5Ah capacity provides moderate runtime for residential mowing or trimming.

Fitment & Compatibility

• Exact models: Compatible with Worx 40V tools listed (WG180, WG280, WG380, WG580, WG776) and chargers WA3747, WA3877. Not compatible with 2x20V or Nitro Series tools.
• Check before buying: Verify your tool’s voltage—must be 40V (not 20V or 80V). Measure battery compartment depth: OEM WA3580 is ~5.5 x 3 x 3.5 inches; this aftermarket unit should match, but confirm dimensions with seller if tight fit is critical.
• OEM vs aftermarket: This is a third-party replacement, not Worx-branded. Performance and lifespan may differ from genuine WA3580.

Key Things to Know

• Quality risk: Only 1 review (1.0/5 stars) suggests potential issues—likely dead on arrival, poor runtime, or swelling. Aftermarket batteries often use lower-grade cells.
• Installation: Tool-free—slide into mower or tool battery port until it clicks. Ensure it locks securely before use.
• Common gotchas: May not fully charge with non-listed chargers. Over-discharge protection may be weaker than OEM, so avoid draining completely. Store indoors, away from heat.
• Warranty: Typically 30-90 days from third-party sellers, versus 2-3 years on genuine Worx. Check return policy before buying.

Should You Buy It

Buy only if you’re on a tight budget and need two batteries for light, occasional use (e.g., small lawn, <30 min per charge). Avoid if you rely on your mower for heavy or frequent cutting—the poor rating and unknown cell quality make a genuine Worx WA3580 (or a better-reviewed aftermarket brand) a safer bet for reliability and longevity.