Choosing the right lawn mower battery size for your backyard can be daunting. In this guide, we’ll walk you through the different sizes and types of lawn mower batteries as well as how to choose the right type for your specific needs.
Lawn Mower Battery Size Explained
Electric lawn mowers use several common battery types. These batteries are categorized under the cold cranking amps (CCA) measurement. It describes how much current a battery can send at zero degrees Fahrenheit without dropping below a certain voltage. Lawn mowers usually use two battery types: Group U1 or Group 24, even though your lawn mower will likely fall into the U1 battery group. Here is a lawn mower battery size comparison for the U1 and U24 group batteries.
U1 Batteries
As the most common types of lawn mower batteries on the market, the U1 batteries come in a standardized size of 8.3 x 5.1 x 7.25 inches with the positive terminal located on the left side of the battery. These mower U1 batteries can have a range of CCA between 200 and 230. They also have 35 to 40 Amp-hour (Ah) capacity and are typically made as 12-volt batteries.
U1-R Batteries
U1-R batteries are one of the Group U1 type of battery. It has a lot in common with U1 batteries, including their dimensions and CCA. The real difference lies in the positive terminal locations of the U1-R batteries, that is, on the right side of the battery. The terminal post on F7, B3, B2 and more can vary. So, remember to ensure you replace the right type of terminal post when selecting a U1-R battery.
U1-3 Batteries
This type of battery is the rarest among the U1 battery group. It offers the highest performance out of all the U1 batteries. They are similar to the U1 battery and share the same dimensions. The U1-3 batteries have a higher CCA, averaging around 340 to 425 and tend to appear on electric lawn tractors or heavy-duty push lawn mowers. They also perform better in colder climates but cost more because of the higher CCA.
Group 24 Batteries
Group 24 batteries are a good fit for your lawn garden tractors or riding lawn mowers with higher capacity and CCA than U1 lawn mower batteries. These batteries are taller than U1 batteries with typically 8.9 inches (23 cm or so) compared to 7.25 inches (about 18 cm) of U1 batteries. Due to the higher CCA than the U1 battery group size, they tend to be more costly, so fewer brands are available for mowers.
Common Types of Lawn Mower Batteries
Lawn mower batteries come in a wide range of types and we list in the table the key information of the main battery types.
| Battery Type | Available in | Charge cycles | Cost | Application |
|---|---|---|---|---|
| Lead Acid Batteries | Flooded(wet cell) and AGM (sealed) type | Only 200 to 300 charges (around 2-3 years with proper care) | $50-$200+ | Most gas-powered riding mowers |
| Lithium-Ion Batteries | Cylindrical and prismatic lithium-ion cells | 300 to 500 charges or even reach 1,000+charge cycles(around 3-5 years) | $200-$1000+ | Common in newer electric and cordless mowers |
| Lithium Iron (LiFe Battery) | Lithium iron phosphate (LiFePO₄) battery packs | 4 to 5 times longer charges cycle than lithium-ion batteries (around 8-15 years) | $300–$1,500+ | Premium electric riding mowers, commercial zero-turn mowers, high-end cordless equipment |
See AGM vs Flooded Battery for Tractor
How to Choose the Right Battery for My Craftsman?
Selecting the right battery for your Craftsman riding lawn mower means understanding your mower’s specifications and how different battery types, sizes, and features can impact performance. You should consider the following key specifications:
Voltage
Your Craftsman lawn mower’s battery will use a specific voltage to power the blades, no matter if it’s a lead-acid or lithium-ion battery. Most modern riding mowers use 12V batteries, while some older or smaller models may use 6V. Always refer to your owner’s manual for confirmation. The size of the battery will often be significantly affected by the battery’s voltage, although a higher voltage causes the battery to weigh more. For example, a 40-volt lithium-ion battery that is used by some heavy-duty lawn mowers will be heavier and more expensive.
Capacity in Amp-Hours (Ah)
The battery capacity of a lawn mower tells you how much current can deliver in 10 hours when fully charged in amps. For modern Craftsman mowers, including the U1 battery group sizes, this battery capacity will range from 10 Ah to 40 Ah. The higher the capacity, the larger the battery will be.
Cold Cranking Amps (CCA)
The CCA shows the cranking current it delivers in amps for 10 hours after a full charge. Most lawn mower batteries will offer around 100 A to 300 A, although a riding mower battery will likely require a higher CCA (at least 145 A).
Size & Terminal Position
It’s important to consider the lawn mower battery size and terminal position when choosing the battery for your Craftsman mowers. Check the BCI Group Size, usually U1, U1L or U1R.
Frequently Asked Questions of Lawn Mower Batteries
How long should a lawn mower battery last?
Generally, it’s not rare for the mower battery to give 5 or more years of use. When you feel your mower crank slower or the battery won’t hold a charge as long between uses, it’s likely time for a replacement.
What size battery do I need for my lawn mower?
For most mowers, a U1 battery is the correct size. Always consult your owner’s manual for confirmation.
Can I use a car battery for my riding lawn mower?
No. Even though they use the same 12V battery, a car battery is too large to fit and secure in your mower.
What kills the battery on a riding lawn mower?
Factors that reduce a lawn mower battery’s life include over/undercharging, extreme temperatures, poor maintenance (dirty terminals, corrosion), frequent deep discharges and natural capacity decline with age. Preventive maintenance and using a battery maintainer during the off-season can keep your lawn and garden batteries powered for their maximum lifespan.
Wrapping up
Selecting the right lawn mower battery size is essential to keep your Craftsman mower ready for the next job. Always consult your owner’s manual for specifications and do regular maintenance to extend the service life of your mower batteries. At FridayParts, you can explore a vast selection of quality mower replacement parts to get your mower back to its optimal performance.
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