KUNLUN 6.0Ah 40 Volt Lithium Battery for Ryobi 40V Battery, High Capacity 40-Volt Lithium Battery Compatible for Ryobi 40V OP4026 OP4030 OP4040 OP40501 OP40602 Batteries

What It Is

This is a high-capacity 6.0Ah lithium battery replacement for Ryobi 40V cordless lawn mowers, string trimmers, leaf blowers, and other outdoor power tools. It provides longer runtime than standard 4.0Ah or 5.0Ah packs, ideal for larger yards or heavy-duty jobs.

Fitment & Compatibility

Before buying, check that your tool uses the Ryobi 40V slide-on battery platform (not the older 18V or 40V backpack system). Compatible with Ryobi models: OP4026, OP4030, OP4040, OP40501, OP40602, and any 40V tool that accepts those packs. This is an aftermarket battery—not OEM Ryobi—so it may not fit tightly in some chargers or tools. Measure your battery slot: the KUNLUN is roughly 5.5 x 3.5 x 4 inches. If your original battery has a different shape or latch design, test fitment with the tool off first.

Key Things to Know

• Aftermarket quality varies: Some users report slightly lower runtime than genuine Ryobi 6.0Ah, but still good for the price. Expect 30-40% more run time than a 4.0Ah pack.
• No battery gauge: Unlike some OEM Ryobi batteries, this one lacks a fuel gauge LED—you’ll need to guess remaining charge.
• Charger compatibility: Works with Ryobi 40V chargers (OP4060, OP4080, etc.), but may charge slower or not fully if the charger has a proprietary chip check. Try your existing charger first.
• Warranty risk: Using aftermarket batteries can void your tool’s warranty if damage occurs. Keep your original battery for warranty claims.

Should You Buy It

Buy this if you need a budget-friendly spare battery for occasional heavy use or multiple tools, and you’re comfortable with slightly less reliability than OEM. Skip it if you want a guaranteed fit, battery gauge, or long-term durability for daily professional use—stick with genuine Ryobi.