2 Pack 8.0Ah WA3674 WA3578 Replacement for Worx Battery 20V WA3578 WA3674 WA3575 WA3525 WA3520 WG151s WG155s WG545s Compatible with Worx 20V Cordless Power Tool

What It Is

This is a 2-pack of 8.0Ah aftermarket lithium-ion batteries for Worx 20V cordless power tools. They’re designed to replace or supplement the original WA3578, WA3674, and other Worx 20V packs, giving you longer runtime for mowers, trimmers, blowers, and other Worx tools in the 20V line.

Fitment & Compatibility

Before buying, confirm your tool uses Worx’s 20V slide-on battery system (not the older 18V or 24V lines). This pack fits models like WA3578, WA3674, WA3575, WA3525, WA3520, and tools such as WG151s, WG155s, WG545s. It will not work with Worx 40V or 56V platforms. Check the battery port shape—if your tool has the standard Worx 20V slide-in slot (flat with a latch at the top), it’s compatible. Measure the battery compartment depth: these are slightly taller than OEM 4.0Ah packs, so ensure your mower or tool has clearance (most do, but some compact trimmers may be tight). This is an aftermarket replacement, not OEM Worx, so expect a plastic housing that may feel less robust.

Key Things to Know

• Quality: Rated 4.5/5 (11 reviews). Users report good runtime (roughly 2x a 4.0Ah pack) but note that capacity may degrade faster than OEM after heavy use. No smart charge management—use only with Worx 20V chargers.
• Installation: Slide on and click, like OEM. No tools needed. Ensure the latch engages fully; some users report a slightly looser fit.
• Common Gotchas: Do not mix with older Worx 18V tools (different voltage/connector). The 8.0Ah adds weight—fine for mowers but may fatigue hand tools. If your tool has a battery cover, check it still closes.
• Warranty: Typically 1-year seller warranty, not Worx. Verify return policy before buying.

Should You Buy It

Buy this if you need extra runtime for your Worx 20V mower or blower and want a budget-friendly 2-pack. Skip it if you prioritize OEM reliability, have a compact tool with tight clearance, or need a battery for heavy daily use—go with genuine Worx for longevity.