RYOBI 40-Volt Lithium-Ion 4 Ah High Capacity Battery

What It Is

The RYOBI 40-Volt Lithium-Ion 4 Ah High Capacity Battery is a rechargeable power source designed for RYOBI’s 40-volt lineup of cordless lawn mowers, trimmers, blowers, and other outdoor tools. It provides longer runtime than the standard 2.6 Ah or 4 Ah batteries, making it ideal for larger yards (up to 1/4 acre) or heavy-use tasks.

Fitment & Compatibility

Before buying, confirm your tool is part of RYOBI’s 40-volt system—this battery will not work with RYOBI’s 18-volt or 36-volt lines. Check your mower’s model number (e.g., RY40180, RY401150) or tool label for “40V MAX” branding. This is an OEM (original equipment manufacturer) battery, so it’s a direct drop-in replacement for any RYOBI 40V tool. No adapter or modification needed. If you’re replacing an old battery, verify the terminal shape matches (all RYOBI 40V batteries use the same slide-on mount). No deck size or measurement checks required—fitment is purely by voltage platform.

Key Things to Know

• Runtime: Expect 45–60 minutes of mowing on a 20-inch deck (depending on grass conditions). About double the runtime of the 2.6 Ah pack.
• Installation: Zero difficulty—slide onto tool until it clicks. No tools required.
• Charging: Use the RYOBI 40V charger (sold separately). Charging time is roughly 2–3 hours from empty. Avoid overcharging; the battery has built-in protection, but unplug once full.
• Common gotcha: This battery is heavier than smaller capacity packs—adds about 1.5 lbs. Not an issue for mowers, but noticeable on handheld tools like trimmers.
• Storage: Keep at 40–80% charge if storing for winter. Do not store fully discharged or in extreme heat/freezing temps.

Should You Buy It

Buy this if you have a RYOBI 40V mower or tool and need more runtime for larger lawns or longer sessions without swapping batteries. It’s a solid upgrade from the standard 2.6 Ah pack, especially for mowing 1/4 acre or more. Skip it if you only have small yards (under 1/8 acre) or use lighter-duty tools—the extra weight and cost aren’t worth it for short tasks.