YSTASTERIS 2 Pack 6.5Ah Replacement for Worx Battery 20V Compatible with Worx 20 Volt Lithium WA3575 WA3578 WA3520 WA3525 and Charger

What It Is

This is a two-pack of 6.5Ah aftermarket lithium-ion batteries designed to power any 20V Worx cordless lawn mower, trimmer, blower, or other tool in the Worx 20V Power Share platform. They replace the OEM WA3575, WA3578, WA3520, and WA3525 batteries, giving you extended runtime for larger yards or continuous use.

Fitment & Compatibility

• Voltage & platform: Must be 20V Worx Power Share tools (most Worx cordless lawn mowers, string trimmers, hedge trimmers, blowers). Not compatible with 18V, 40V, or 56V Worx tools.
• Model numbers: Directly replaces WA3575, WA3578, WA3520, WA3525. Also works with any tool that accepts those OEM batteries (e.g., WG383, WG384 mowers, WG163 trimmer).
• Physical fit: Same shape and slide-in mounting as OEM. Measure battery compartment depth if using in older or compact tools—6.5Ah cells are slightly longer than 2Ah or 4Ah packs.
• Charger compatibility: Works with all Worx 20V chargers (standard and rapid). No adapter needed.

Key Things to Know

• Capacity vs. weight: 6.5Ah gives roughly 3x the runtime of a 2Ah battery, but the pack is noticeably heavier. May affect balance on handheld tools.
• Aftermarket trade-offs: No Worx warranty or over-discharge protection as robust as OEM. Some users report shorter overall lifespan (200–300 cycles vs. 500+ for genuine Worx).
• Installation: Simple slide-on, no tools. Ensure latch clicks fully; loose fit can cause intermittent power loss.
• Charging time: On a standard Worx charger, expect 4–5 hours from empty. Faster with the WA3881 rapid charger.

Should You Buy It

Buy if you need affordable extra runtime for a large lawn or multiple tools, and you’re comfortable with aftermarket battery risk (no warranty, slightly shorter life). Skip if you want OEM reliability, lighter weight for handheld use, or have older Worx tools with tight battery compartments.