20V 6.5Ah High-Capacity Battery Replacement for Worx Battery 20V PowerShare WA3578 WA3674 WA3575 WA3525 WA3520 WG155s WG251s WG890 WG891 Compatible with Worx 20 Volt Cordless Tools (2 Pack)

What It Is

This is a 20V 6.5Ah lithium-ion battery replacement for Worx’s PowerShare platform, designed to power 20V cordless lawn mowers, trimmers, blowers, and other tools that use the WA3578, WA3674, WA3575, WA3525, or WA3520 battery packs.

Fitment & Compatibility

• Platform check: Only for Worx PowerShare 20V tools (not 40V or 56V). Common compatible models include WG155s, WG251s, WG890, WG891, and others using the same slide-in mount.
• Physical fit: Same dimensions as OEM WA3578 (approx. 5.5 x 3 x 2.5 inches). Verify your tool’s battery compartment depth and latch alignment – aftermarket tolerances can vary slightly.
• OEM vs aftermarket: This is a third-party replacement, not made by Worx. It will not work with Worx chargers that have proprietary communication chips (some newer chargers may reject it). Test with your charger before full use.
• Capacity: 6.5Ah is higher than most OEM 2.0Ah or 4.0Ah packs. Ensure your tool’s motor and wiring can handle the extra runtime without overheating (most can, but check manual for max Ah rating).

Key Things to Know

• Charger compatibility: May not charge in Worx “smart” chargers with data pins. Use a basic Worx 20V charger (like WA3730 or WA3746) for best results.
• Installation difficulty: Trivial – slide onto tool until latch clicks. No tools needed. If it feels loose, the plastic molding may be slightly undersized; return for replacement.
• Heat management: 6.5Ah packs run hotter during heavy use (e.g., mowing tall grass). Let the battery cool between charges to avoid swelling or reduced lifespan.
• Warranty: Aftermarket batteries typically have a 1-year limited warranty (read seller’s policy). OEM Worx packs have 2–3 years but cost 2–3x more.

Should You Buy It

Buy this if you have multiple 20V Worx tools and want extended runtime for mowing or trimming without paying OEM prices. Skip it if you rely on a single smart charger that rejects third-party packs, or if you need guaranteed compatibility with newer Worx tools (2023+ models). For the price, it’s a solid value for older or non-smart tool platforms.