2-Pack 6.5Ah Replacement for Worx 20V Battery, Replaces WA3520 WA3575 WA3571 WA3577, Compatible with Worx Battery 20V Power Share Tools WG251s WG255s WG540s WG890 WG891 and More

What It Is

This is a 2-pack of 6.5Ah aftermarket batteries designed to replace Worx’s WA3520, WA3575, WA3571, and WA3577 OEM batteries. They power any 20V Worx Power Share tool, including mowers (WG251s, WG255s, WG540s), trimmers, blowers, and chainsaws.

Fitment & Compatibility

• Check your tool’s voltage: Only for 20V Worx Power Share tools—not 40V or 56V models.
• OEM part numbers: Directly replaces WA3520, WA3575, WA3571, WA3577. If your original battery has a different number (e.g., WA3550), measure physical dimensions and confirm the slide-in connector matches.
• Physical size: 6.5Ah cells are taller/heavier than standard 2Ah packs. Ensure your mower’s battery compartment has clearance (especially under the deck or in tight slots).
• Charger compatibility: Works with Worx 20V chargers (e.g., WA3820, WA3880). Do not use with NiCad or 40V chargers.

Key Things to Know

• Capacity vs. weight: 6.5Ah gives ~3x runtime of a 2Ah pack, but adds noticeable weight—may unbalance handheld tools like trimmers.
• Aftermarket quality: 3.2-star rating (5 reviews) indicates potential variance in cell quality, lifespan, or fitment. Expect shorter cycle life than OEM.
• No installation: Slide onto tool—no tools required. Ensure terminals align; if tight, do not force.
• Storage: Store at 40–80% charge in cool, dry place. Full discharge or high heat accelerates degradation.

Should You Buy It

If you need extra runtime for long mowing sessions and don’t mind the added weight, this 2-pack is a budget-friendly alternative to OEM. But with limited reviews and average ratings, it’s a gamble—buy only if you’re comfortable with potential shorter lifespan or fitment issues. For critical tasks or heavy daily use, stick with genuine Worx batteries.