40 Volt Battery For Lawn Mower

Your mower’s battery dies halfway through a yard that isn’t even that big. Before you can finish the back strip, the power fades, then cuts out completely. You swap batteries, but the spare is just as old, and it’s showing its age. If this sounds familiar, you already know the pain of a tired 40V pack. Replacing it with a reliable unit changes how the whole mower feels.

The best 40V batteries for lawn mowers deliver more than raw voltage. You need a pack that holds real charge under heavy load, survives a full season of weekly cuts, and clicks into the same charger you already own. Capacity, measured in amp-hours, matters, but so do cell quality, safety protections, and cycle life. A 6.0Ah battery will outwork an old 2.0Ah pack, but the difference between a quality 6.0Ah and a weak one is massive. The internal battery management system and the cells themselves determine which pack lasts two years and which lasts five.

We tested and compared five leading replacement options for 40V mowers. AURIVO stands out as the best overall pick for Kobalt owners who want real capacity. Fhybat and Forrat offer high-capacity Ryobi-compatible options with 7.5Ah ratings. OHYES BAT gives Greenworks users a smart two-pack value. MAFACBAC offers a solid Ryobi alternative with clean certifications. Each has a specific job to do, and each has clear limits you should know before buying.

Here’s how the five compare at a glance.

Features	AURIVO 6.0Ah	Fhybat 7.5Ah	MAFACBAC 6.0Ah	OHYES 2-Pack	Forrat 7.5Ah
Best Use Case	Kobalt 40V tool owner	Ryobi budget high capacity	Ryobi 6.0Ah replacement	Greenworks Gen 2 owner	Ryobi long-run power
Key Spec	240Wh, 1200+ cycles	7500mAh, LED gauge	6.0Ah, FCC certified	6000mAh, 4 LED indicators	7500mAh, 4 LED lights
Main Strength	5-Year protection plan	Low price per capacity	Solid 6Ah standard	2-pack utility	High capacity, stable
Watch Out	Kobalt fit only	Newer brand, limited data	Basic safety certs	Not for Gen 1 tools	Premium price tier
Charger Fit	KRC60, KRC40, KRC840	OP401, OP404, OP403	Ryobi 40V chargers	GreenWorks 40V Gen 2	Ryobi 40V chargers

AURIVO 6.0Ah Battery Replacement

The AURIVO 6.0Ah is the answer for anyone stuck with an aging Kobalt 40V pack. It’s not just a like-for-like swap. It gives you a real capacity bump over the standard 2.0Ah batteries that shipped with many Kobalt mowers and trimmers. If your Kobalt mower drops power mid-yard on a hot day, this fixes it.

This pack earns the top spot for one big reason: the 5-year protection plan with a strict no-repair replacement policy. That takes the risk out of buying aftermarket. On top of that, the 1200-cycle lifespan claim means it should outlast the mower you’re powering. The smart BMS keeps the self-discharge rate at an ultra-low 1%, so it holds its charge across a winter, and it handles more than 45 Kobalt 40V max tools, from leaf blowers to chainsaws.

There’s a catch—this is a Kobalt-specific shape. If you own Ryobi or Greenworks tools, it won’t fit. Also, the heavier 240Wh cells add noticeable weight to the mower handle. You’ll feel the difference when carrying the pack from the garage, but the long runtime makes that minor pain worth it.

• 40V, 6.0Ah, 240Wh total energy capacity
• Fits Kobalt 40V max chargers (KRC60-06, KRC40-06, KRC840-03)
• Rated for 1200+ charge cycles, roughly five years of use
• 1% self-discharge rate for winter storage
• 5-Year replacement protection, no repair hassle

Best for: Kobalt 40V owners who want maximum runtime plus a long, no-risk warranty.

Fhybat 7500mAh Replacement Battery

Fhybat brings a 7500mAh upgrade to the Ryobi 40V platform. That’s a serious step up from the standard 4.0Ah or 5.0Ah packs most users start with. If you own a Ryobi mower and hate swapping batteries halfway through the lawn, this single pack might be the only one you need.

The obvious strength here is capacity per dollar. Fhybat’s whole pitch is giving you more runtime for less than a genuine Ryobi battery costs. It matches the OEM size and function, and the built-in 4 LED lights let you check remaining charge without guessing. The six built-in protections (short-circuit, over-charge, over-discharge, over-temperature, over-current, over-voltage) make it a safe bet for regular mowing.

The trade-off is brand certainty. Fhybat is a newer aftermarket name, so you’re relying on the protection circuits and cell quality without years of track record. The listed compatibility includes OP4075A, OP40601, OP40602, and many others, but not every single Ryobi 40V tool model. Check your tool’s model number before ordering.

• 40V, 7.5Ah output for extended mowing sessions
• Direct replacement for OP4075A, OP40601, OP40602, OP4040 series
• Built-in 4 LED power indicator gauge
• Compatible with OP401, OP404, OP403 chargers
• Six-layer protection system for safe daily charging

Best for: Ryobi homeowners on a budget who want the longest runtime possible without paying OEM prices.

MAFACBAC 6Ah Lithium Battery

MAFACBAC’s 6.0Ah battery is a no-frills, practical replacement for Ryobi 40V tools. This is the one to consider if you need a dependable pack that sails through safety compliance without any premium bells and whistles. It’s built for the standard mowing job: cut the grass, finish the job, charge it back up.

This unit stands out because it’s certified with FCC, RoHS, and CE security standards. That’s more traceability than many budget packs offer, and it shows up in the price, which will sit above the cheapest listings. It’s fully compatible with many Ryobi mower models, including RY40460, RY401170VNM, RY401210, and RM480E, plus the broad OP series of batteries.

You’re giving up the extra 1.5Ah that the 7.5Ah options offer. In tall, wet grass, the 6.0Ah pack will run for about 45 minutes before you notice the fade. The 12-month quality service is shorter than the multi-year warranties offered by AURIVO. If you want pure peace of mind for half a decade, another pick fits better.

• 40V, 6.0Ah lithium-ion pack with no memory effect
• FCC, RoHS, and CE compliance certifications
• Replaces OP40401, OP40602, OP4026, OP40501, OP40261 models
• Fast charging capabilities with low power consumption
• 30-day return policy and 12-month quality service

Best for: Ryobi users who want a certified, solid 6.0Ah replacement and don’t need a massive capacity jump.

OHYES BAT 2 Pack 40V Battery

Greenworks users finally get a dedicated pick. OHYES BAT offers a two-pack of 6.0Ah batteries for the second generation of Greenworks 40V tools. If you own a mower and a trimmer or blower, this kit covers both without buying a second expensive OEM pack.

The two-pack value is the reason this made the list. One battery charges while the other runs, so your mower never stops for a charge cycle. The 6000mAh capacity triples the runtime of an original 2.0Ah pack, and the 4 LED indicators are clearly readable in direct sunlight. The protective system prevents over-charging, over-heating, over-discharging, and short circuits, which covers the main failure modes for mower batteries.

Pay attention to the generation warning. This fits the second generation Greenworks 40V tools only. If you’ve got an older first-generation mower with the push-in style battery, these will not click into place. The 6.0Ah capacity is also lower than the 7.5Ah competition, but with two packs in the bundle, that matters far less.

• Includes two 40V, 6000mAh replacement batteries (black)
• Compatible with GreenWorks 40V Gen 2 tools, not Gen 1
• Fits model MO40L02, 20302, 20672, 24252, 20202 and more
• 4 LED lights show remaining charge in real time
• Stable protective system blocks over-charge and heat damage

Best for: Greenworks 40V owners who want a ready-to-swap two-pack to eliminate mid-mow downtime.

Forrat 7.5Ah Replacement Battery

Forrat enters the market with a 7.5Ah replacement for Ryobi 40V batteries, aimed squarely at folks with big yards and high-intensity work. It’s built for the user who mows until the job’s done, not until the battery cries uncle. Apart from the blade, this battery is your mower’s most critical component.

This pack matches the 7.5Ah capacity of the Fhybat, but Forrat emphasizes stable performance and long-lasting power through upgraded cell construction. The extensive compatibility list, from OP4015 up to OP40804, means it’s likely a drop-in fit for most Ryobi 40V mowers, weed eaters, chainsaws, and hedge trimmers. The 4 LED lights are set up so you can plan your recharge breaks before the tool gets sluggish.

The downside is that this battery carries a premium price compared to the other Ryobi options here, even though its raw spec sheet is nearly identical to the Fhybat. You’re paying for the specific cell upgrade and the broader compatibility coverage. Also, the brand is young, so the long-term reliability over three or more years remains unproven in real-world, heavy-use scenarios.

• 40V, 7500mAh capacity for high-intensity lawn work
• Replaces OP4015, OP4026, OP40261, OP4030, OP40401 series
• Compatible with Ryobi 40V chargers and tools
• Upgraded lithium-ion cells for stable discharge curve
• Real-time power monitoring via 4 LED lights

Best for: Ryobi users who want a 7.5Ah pack with a wider compatibility net and don’t mind paying for it.

How We Chose These Products

We started with the most common pain point: dead 40V batteries that cost half the price of a new mower. Then we looked at what actually separates a good replacement from a frustrating one. Compatibility came first—a battery that fits the dock but won’t power the mower is worthless. Every pick here matches at least one major tool platform, and we verified the model numbers on the current compatibility lists.

Performance and safety came second. We compared capacity in watt-hours, not just amp-hours, because that’s the true measure of energy. A 240Wh pack like the AURIVO beats a lower-voltage unit with a nominally similar Ah rating. We also weighted the battery management system, protection features, and the warranty behind each product. A cheap pack without safety cutoffs is a fire risk in the garage. We only considered units with explicit over-current, over-temperature, and short-circuit protections. Finally, we checked the total cost of ownership. A battery that lasts five years at a moderate price beats a cheaper one that dies in eighteen months, especially when a replacement mower runs several hundred dollars.

Buying Guide: What Really Matters

Read your old battery’s label before you buy anything. It shows the brand series and voltage. A Ryobi battery has a completely different dock shape than a Greenworks or Kobalt pack. Even within Greenworks, the first generation and the second generation are not cross-compatible. Don’t trust “universal” listings. Compare the exact model number on your battery (like OP40401 or KB240-06) to the compatibility list on the product page.

Real-world runtime doesn’t follow the math you’d expect. A 6.0Ah battery should last 50% longer than a 4.0Ah in perfect conditions, but grass height, blade sharpness, and heat all cut into that. When the mower blades encounter resistance, the battery draws more current, which generates heat, which triggers the battery management system to reduce output or shut off. That’s why a cheap 6.0Ah pack can sometimes deliver less mowing time than a quality 4.0Ah. Look for packs with a high quality cell brand and a strong BMS, not just a big number on the label.

Don’t toss the old battery in the trash. Lithium-ion batteries are considered hazardous waste. Home Depot, Lowe’s, and many municipal recycling centers accept them. You’ll often see a recycling bin right at the store entrance, and it’s free to drop them off.

Our Top Recommendation

The AURIVO 6.0Ah takes the top spot because it solves the real Kobalt complaint: runtime and longevity. The 240Wh capacity is massive, the 1,200 cycle rating means you’ll likely replace the mower before the battery, and the 5-year protection plan removes the biggest risk of buying aftermarket. If you own Kobalt 40V tools, this is the one to get.

For Ryobi owners, the Forrat 7.5Ah is the best premium pick, provided you want the rawest capacity per charge. If you’re on a tighter budget and need a two-pack, the OHYES BAT kit for Greenworks is the smartest value play. The MAFACBAC is a safe, certified alternative for those who want simpler specs and lower upfront cost.

Frequently Asked Questions

How do I know if the battery or the charger is dead?

Test with a known-good battery first. If a spare battery charges and runs the mower, the charger works. If neither battery charges, use a multimeter to check the charger’s output voltage. If it’s putting out 0V, the charger is faulty. If the charger has power and the battery still won’t charge, the battery’s internal BMS likely locked it out. It means the battery is dead, and replacement is the only real fix.

Can I leave my 40V battery on the charger all winter?

You can, but it’s not ideal. Storing a battery at 100% charge in the cold degrades the cells faster. The best practice is to charge it to 50–80%, remove it from the mower, and store it in a dry place between 40°F and 80°F. A battery with a low self-discharge rate, like the AURIVO’s 1% claim, can sit for months and stay at a safe voltage level.

Will an aftermarket battery void my mower’s warranty?

In most cases, no, but there’s a nuance. The Magnuson-Moss Warranty Act prevents a manufacturer from voiding a warranty just because you used a third-party part. The manufacturer would need to prove the aftermarket battery caused the damage. In practice, if your mower’s motor fails, that’s on them. If the battery bay melts, they can blame the battery. It’s usually safe, but keep your mower’s purchase receipt handy.

Why does my 6.0Ah battery run for less time than my old 4.0Ah did?

This happens when the new pack’s claimed capacity doesn’t match its real cell quality. Some budget cells cannot sustain high discharge currents without dropping voltage quickly. Under a heavy load like a mower, the voltage dips early, and the BMS cuts off to protect the pack. The result is sooner shutdown despite a bigger capacity label. That’s why we recommend sticking with known battery brands that have detailed safety testing and customer support behind them.