2Pack Replacement for Worx Battery 20V 3Ah Compatible with WA3525 WA3520 WA3575 WG151s WG155s WG251s WG255s WG540s WG545s WG890 WG891

What It Is

This is a 2-pack of aftermarket 20V 3Ah lithium-ion batteries for Worx cordless lawn mowers, trimmers, and other 20V Power Share tools. Each battery delivers 54 watt-hours (20V x 3Ah) to run your machine for roughly 30–45 minutes of moderate mowing, depending on blade load and grass conditions.

Fitment & Compatibility

• Directly replaces Worx models WA3525, WA3520, WA3575, and fits tools listed in the title (WG151s, WG155s, WG251s, WG255s, WG540s, WG545s, WG890, WG891).
• Check your tool’s voltage and battery compartment shape – this is a slide-on, rear-mount battery (not a plug-in or top-mount). If your mower uses a different battery interface (e.g., WA3550, WA3580), this won’t fit.
• OEM vs aftermarket – Not a genuine Worx battery. It may lack the same over-discharge protection or temperature sensors, so check if your mower’s BMS (battery management system) tolerates third-party packs.
• Measure battery dimensions – These are roughly 4.5” x 3” x 2.5”. Verify your tool’s battery bay isn’t too tight or shaped differently (e.g., for the WG890/891, it should slide in fine).

Key Things to Know

• Quality variance – Aftermarket batteries often use lower-grade cells (e.g., generic 18650s) that may degrade faster or deliver less runtime than OEM Worx batteries. Expect ~80% of original capacity after 50–100 cycles.
• Installation – Zero difficulty. Slide onto the tool’s battery mount until it clicks. No tools or wiring required.
• Common gotchas – Some users report the battery doesn’t charge on Worx-brand chargers (WA3730, WA3740) due to compatibility chips. Use the included charger if possible. Also, the charge indicator light may be inaccurate or missing.
• Safety note – Aftermarket packs may lack overheat protection. Avoid leaving them in direct sun or charging immediately after heavy use.

Should You Buy It

This is a budget-friendly option if you need two spare batteries for light-duty trimming or small mowers (under 14” cut) and don’t mind occasional shorter runtime or slight fitment quirks. For heavy mowing or long sessions, stick with genuine Worx WA3525s for reliability and warranty.