When your Craftsman lawn mower refuses to start, a failing battery is often the culprit. Finding the right replacement is crucial for getting your yard work back on track and ensuring your mower has the reliable power it needs for a strong start and consistent performance. With various battery types and models available, selecting the perfect match for your specific Craftsman tractor or 20V MAX tool can feel overwhelming.
This roundup simplifies your search by highlighting eight of the best replacement batteries for Craftsman equipment in 2025. We’ve compiled options for both riding mowers that require a 12V starting battery and cordless mowers that use the 20V MAX lithium-ion platform. Our goal is to provide you with the information needed to make a confident purchase and get your lawn looking pristine again.
The Best Craftsman Lawn Mower Replacement Batteries
- Mighty Max Battery ML-U1R-CCA 12V 200CCA Replacement
- Mighty Max Battery ML-U1 12V 200CCA Battery
- Mighty Max Battery ML18-12 – 12V 18AH New Battery
- Craftsman 20V MAX 5Ah Lithium Ion Battery (CMCB205)
- Craftsman 20V MAX 2.5Ah Lithium Ion Battery (CMCB202)
- Craftsman 20V MAX 4.0Ah Lithium Ion Battery (CMCB204)
- Craftsman 20V MAX 6.0Ah Lithium Ion Battery (CMCB206)
- Craftsman 20V MAX 2.0Ah Lithium Ion Starter Battery
Mighty Max Battery ML-U1R-CCA 12V 200CCA Replacement Battery
This Mighty Max battery is engineered as a direct replacement for Craftsman LT1000 models and other tractors requiring a U1R form factor. It delivers a strong 200 Cold Cranking Amps (CCA), providing the necessary power to start your engine reliably, even in cooler weather. The sealed lead acid (SLA) design is maintenance-free and spill-proof, allowing for safe installation in various orientations without the risk of acid leaks.
With dimensions of 7.62 x 5.00 x 6.25 inches and positive-right polarity, it is built to fit perfectly into the designated battery tray. This battery is known for its high discharge rate, long service life, and ability to recover from deep discharges, making it a durable and cost-effective solution for your riding mower.
Mighty Max Battery ML-U1 12V 200CCA Battery
For Craftsman 25780 lawn tractors and similar mowers, the ML-U1 from Mighty Max offers a compatible 12V power source. It shares the same 200 CCA rating as the U1R model, ensuring a dependable start every time you turn the key. The key difference lies in its physical configuration, with a slightly taller profile and polarity that is reversed (Positive on Left, Negative on Right).
This AGM battery is completely sealed and requires no watering, offering a hassle-free ownership experience. Its construction supports wide operating temperatures and resists vibration, which is common in outdoor power equipment. This is a straightforward replacement that focuses on performance and longevity.
Mighty Max Battery ML18-12 – 12V 18AH New Battery
If your Craftsman black lawn mower uses the 90508011 battery, the ML18-12 is a perfect match. This battery is rated at 12V and 18 Amp-hours (AH), which is a measure of capacity, indicating it can deliver a lower amount of power over a longer period. This makes it ideal for applications beyond just starting, such as providing power for electrical components or in certain utility vehicles.
Featuring nut and bolt terminals, it ensures a secure and solid connection. As a UL Certified product, it meets specific safety standards, giving you added peace of mind. Its compact dimensions and spill-proof AGM technology make it a reliable and safe choice for your specific mower model.
Craftsman 20V MAX 5Ah Lithium Ion Battery (CMCB205)
The Craftsman CMCB205 5.0Ah battery strikes an excellent balance between runtime and weight for your 20V MAX cordless mower and other tools. The higher Amp-hour rating means you can mow for a longer period on a single charge compared to standard-capacity batteries. This reduces interruptions and allows you to complete larger lawns without needing to stop and recharge.
As an official Craftsman battery, it is guaranteed to be fully compatible with all tools in the 20V MAX ecosystem. It incorporates advanced lithium-ion technology for minimal self-discharge, so it holds a charge longer while in storage. This battery is a great choice for users who need extended power without the bulk of the highest-capacity option.
Craftsman 20V MAX 2.5Ah Lithium Ion Battery (CMCB202)
For lighter-duty mowing tasks or as a handy backup, the 2.5Ah battery is a compact and lightweight option. Its smaller size reduces the overall weight of your mower, which can be beneficial for maneuvering and for users who prefer a lighter tool. It provides sufficient power for smaller lawns or for finishing a job when your primary battery is depleted.
This battery is also ideal for powering other 20V MAX Craftsman tools like string trimmers, blowers, and drills where a lighter battery is advantageous. It charges quickly and is a cost-effective way to expand your collection of batteries, ensuring you always have a charged power source ready to go.
Craftsman 20V MAX 4.0Ah Lithium Ion Battery (CMCB204)
Sitting between the compact 2.5Ah and the robust 5.0Ah models, the 4.0Ah battery offers a solid boost in runtime without a significant increase in size or weight. It is an excellent all-around battery for medium-sized lawns, providing a noticeable improvement in performance over the entry-level options.
You will appreciate the extra mowing time this battery provides, allowing you to cover more ground before needing a recharge. It represents a strong value, delivering a great mix of capacity and affordability for the average homeowner with a cordless Craftsman mower.
Craftsman 20V MAX 6.0Ah Lithium Ion Battery (CMCB206)
For the maximum possible runtime on your Craftsman cordless mower, the 6.0Ah battery is the top-tier choice. This high-capacity power source is built for tackling very large lawns or for users who do not want to think about battery life at all during their mowing session. It minimizes the chance of running out of power before the job is done.
While it is the largest and heaviest battery in the 20V MAX lineup, the trade-off is unparalleled endurance. If you have extensive property or simply prefer the convenience of less frequent charging, investing in the 6.0Ah battery is a decision you will be glad you made.
Craftsman 20V MAX 2.0Ah Lithium Ion Starter Battery (CMCB200)
Often included as part of a tool kit, the 2.0Ah starter battery is the most compact option in the Craftsman 20V MAX family. It is perfectly suited for low-drain applications and is an excellent introductory battery. Its light weight makes it ideal for use with smaller tools, but it can also serve as an emergency backup for your mower.
This battery is a practical and economical choice for those who are new to the Craftsman cordless system or for powering tools that do not demand a high capacity. Having one of these on hand ensures you are never completely without power, even if your main batteries are charging.
Buying Guide: How to Choose the Right Craftsman Lawn Mower Replacement Battery
When my old Craftsman mower battery finally gave out, I realized there’s more to picking a new one than just grabbing the first option I saw. You need to make sure you get the right fit, both physically and electrically, to get your mower running smoothly again. The most important thing is to match the voltage. Most Craftsman riding mowers use a 12V battery, but some models might be different. Always double-check your mower’s manual or the label on your old battery to be certain. Getting this wrong can damage your mower’s electrical system.
Next, look at the Cold Cranking Amps (CCA). This rating tells you how well the battery can start your engine in cold weather. A higher CCA is generally better, especially if you live in a region with chilly springs. For lawn mowers, a rating between 200 and 300 CCA is usually sufficient. Then there’s the Amp-Hour (Ah) rating, which indicates the battery’s capacity—how long it can power your mower’s accessories if you have them. A higher Ah means it can last longer between charges.
The terminal configuration is a small detail that can cause a big headache. Look at your old battery and see if the positive and negative terminals are in the same place. You need a new battery with the same orientation, or the cables might not reach. Also, pay attention to the physical size. Will it fit snugly in the battery tray? A battery that’s bouncing around can be a safety hazard.
Finally, consider the battery type. Standard flooded lead-acid batteries are common and affordable, but they may require occasional maintenance, like adding water. Absorbent Glass Mat (AGM) batteries are sealed, maintenance-free, and typically offer better vibration resistance and a longer lifespan. While they cost a bit more, the convenience and durability are often worth the investment for a piece of equipment that gets shaken around a lot. Taking these few factors into account will help you find one of the best Craftsman lawn mower replacement batteries for your needs in 2025.
Frequently Asked Questions
How long should a Craftsman lawn mower battery last?
With proper care, a good quality lawn mower battery should last between three to five years. This lifespan can be shorter if the battery is frequently deeply discharged, left in a discharged state for long periods, or exposed to extreme temperatures. Using a smart battery tender or maintainer during the off-season is one of the best ways to extend its life.
Can I use a car battery in my Craftsman riding mower?
While a car battery might physically fit and have the same voltage, I don’t recommend it. Lawn mower batteries are designed as starting batteries with high CCA for a short, powerful burst to turn the engine over. Car batteries are often hybrid or deep-cycle designs for a different kind of use. A mower-specific battery is built to handle the constant vibration from the engine, which a car battery isn’t, leading to a premature failure.
What is the best way to store my mower battery over the winter?
Don’t just let it sit in a cold garage all winter! The best practice is to fully charge the battery, disconnect it from the mower, and store it in a cool, dry place. For the best results, connect it to a battery maintainer or tender. This smart device will keep it at an optimal charge level without overcharging, ensuring it’s ready to go when spring arrives.
Why does my new battery keep dying?
If you’ve just installed one of the new Craftsman lawn mower replacement batteries and it’s already losing charge, there are a couple of common culprits. First, check that the battery terminals are clean and tight. Second, your mower might have a parasitic drain—something is drawing a small amount of power even when the key is off. The most likely cause, however, is the charging system on your mower itself. The alternator or voltage regulator might be failing and not properly replenishing the battery as you mow.
Are all 12V lawn mower batteries the same?
Definitely not. As I learned, you have to look beyond the voltage. The physical dimensions, terminal placement, CCA rating, and Ah capacity can all vary significantly. A battery that’s perfect for a light-duty riding mower might not have the starting power for a larger, more powerful tractor model. Always cross-reference the group size and specifications of your old battery to ensure compatibility.