2Packs WA3520 7.0Ah Li-ion Replacement for Worx Battery 20V Max Lithium Battery Compatible with Worx 20V Battery WA3578 WA3575 WA3525 WG151s WG155s WG251s WG255s WG540s WG545s

What It Is

This is a two-pack of 7.0Ah lithium-ion batteries designed to replace Worx 20V Max batteries. They power any Worx 20V cordless tool, including lawn mowers, trimmers, blowers, and chainsaws from the WA and WG series.

Fitment & Compatibility

Check your tool’s voltage requirement. These are 20V max (18V nominal) batteries. They fit all Worx 20V Max tools, but not 40V or 56V models. Verify your existing battery model number—compatible with WA3578, WA3575, WA3525, and WG151s, WG155s, WG251s, WG255s, WG540s, WG545s. Not compatible with older Worx 18V NiCad tools or any non-Worx brand. Physically measure your battery compartment: these are the standard Worx slide-pack size (approx. 5.5 x 3 x 2.5 inches). If your tool has a different battery interface (e.g., side-post or push-fit), these won’t work.

Key Things to Know

• Capacity vs. OEM: 7.0Ah is higher than Worx’s standard 2.0Ah or 4.0Ah packs, meaning longer run time per charge—good for larger lawns or heavy trimming.
• Build quality: Aftermarket batteries often have lower-quality cells. Several reviews mention early capacity loss or failure after 6-12 months. The 3.8 rating reflects mixed durability.
• No charger included: You must use your existing Worx 20V charger. These batteries are compatible with all Worx 20V chargers.
• Safety note: Aftermarket Li-ion packs may lack over-discharge protection. Avoid fully draining them to extend lifespan.

Should You Buy It

Buy this if you need a budget-friendly way to get two high-capacity spares for your Worx 20V tools and you’re comfortable with the risk of shorter lifespan versus OEM. Avoid if you rely on the tool daily for commercial work or want the longest possible battery life—OEM Worx packs (WA3578) are more reliable.