Riding mower battery voltage. Battery Testing

Do you have to Charge a New Lawn Mower Battery?

You obtained a brand-new lawn mower and are eager to use it immediately, but you may be wondering whether to charge the battery first or not. Typically, a battery is essential in powering battery-powered push lawn mowers and in starting a riding lawn mower engine. So, do you have to charge a new lawn mower battery?

The answer is no: New electric push mower batteries usually have enough charge to power the mower. However, this is not always the case. You have to charge the battery if it doesn’t have enough power to run your lawn mower.

Do you have to charge a new lawn mower battery?

The answer to this question depends on the type of lawn mower you are using. Let’s have a look at each of them:

Push Mowers

In the recent decade of years ago, it was impossible to run lawnmowers on a battery since they needed a lot of power to engage the blades. With improving technology, there was an invention of lithium-ion batteries that could power most farm tools.

When you purchase a new battery push mower, you expect the battery to have at least some charge to power it on and mow a patch of grass. However, the battery may not be fully charged, especially if the mower has stayed in the store for a long time after obtaining it from the factory.

In this case, you must recharge the battery fully before using the mower. Additionally, it may depend on what the manufacturer recommends. Some batteries have to be fully charged before using for the first time.

Always use the right type of charger when recharging your new battery. The battery’s voltage is the main factor to consider when selecting a charger. Modern lawnmowers have a 12-volt battery, while older mowers may have a 6-volt system and battery.

Modern battery chargers have different features such as automatic shutoff, hookup failsafe, float charging mode, controlled amp rates, integrated charging timer, and multiple mode settings, making it impossible to overcharge a lawn mower battery.

Riding Mowers

Riding mowers are equipped with a large-capacity lead-acid battery like those found in cars. The batteries are only intended to start the mower’s engine. You don’t need to charge these batteries. When a riding mower is in use, it can recharge the batteries on its own.

Like other types of batteries, riding lawn mower batteries may lose charge in time. They cannot hold a charge or may contain some charge, but the voltage is too low to perform any task, such as starting the engine. The only solution is to replace them.

How long do you charge a new lawn mower battery?

Generally, it takes 6 to 12 hours to charge a new lawn mower battery. However, several factors determine battery charging time. They include:

The voltage of the Battery

The battery’s voltage determines the time it takes to charge and how long it will last after charging. Most modern lawnmowers use a 12-volt system and batteries. However, those that were made earlier than the 1980s use a 6-volt system and batteries.

Lawn mower battery voltage also depends on how large the mower is and the year it was produced. Larger mowers require 12 volts or higher voltage to power their system as compared to smaller mowers. This is evident in modern lawnmowers.

Typically, it may take 6 hours to charge a 6-volt battery and 12 hours for a 12-volt battery. However, the charging time may vary depending on the mode of charging and the time the battery has been used between the charges.

The Charging Amperage

Amperage also affects the charging time of a lawn mower battery. Amperage is the current’s strength measured in amperes, better known as amps. An average charger for a 12 volts lawn mower battery is 10 amps.

However, you have different options because many chargers come with settings ranging from 2 amps to 10 amps or more. Fast charging will take more amps with less charging time, while slow charging will take fewer amps with more charging time.

Using 6 or 7 amps is recommended when charging a new lawn mower battery. Raising or lowering the amps reduces or lengthens the charging time. Slow charging increases the efficiency and durability of the battery.

Run Time of the Lawn Mower

The run time of the battery is also determined by age and capacity. A new lawn mower battery has a longer run time with fewer charging needs. Generally, larger-capacity batteries will take more time to charge and run longer than small-capacity ones.

Frequency of Use

How you use your lawn mower also determines how long the battery needs to charge. If you mow your lawn frequently, you’ll need to charge the battery more often. Your battery can drain the power when you forget to power off the mower.


Before attempting to jump-start, check that the battery is secure and not leaking. Leaking battery acid will burn your skin, so if the battery is wet, use gloves and eye protection. Check also that the terminals are secure and not damaged. Damaged or loose terminals will cause arcing and prevent power flow to the starter.

If your battery posts are dirty, clean them before jump-starting. First, kit yourself out with protective eyewear and gloves. It will look like a white crusty build-up on the terminals and battery posts.

Dirty, corroded, or loose terminals create resistance to the flow of power from the battery to your starter and, in return, prevent the recharging of the battery by the alternator.

Sprinkle some baking soda on the terminals and add a small amount of water. This will neutralize the acid and remove the corrosion.

Use a wire brush to clean the surface. Now remove the terminals and clean around the poles and the terminals. Apply a coat of petroleum jelly to help protect against corrosion.

Cleaning The Battery Terminals

Battery terminals (connections) often come loose because of mower vibration, and as you know, corrosion is also common. If your battery terminals are damaged or badly corroded, replace them. Damaged cables may have broken wires within. This causes excessive resistance.

Often you may notice the cables getting very hot while you’re attempting to start the mower. This is a sign of high resistance. Replace with good quality leads and terminals.

Cables – Damaged, worn, or dirty cables will mimic a flat battery. Always check battery cables and terminals before condemning the battery.

Jumping / Boosting Your Mower

The jump/Boost start procedure is very simple; obviously, you’ll need a set of booster cables. If you need to buy boosters, buy a good quality set. Poor quality cables won’t make a good connection and make the whole job a lot more difficult.

I recently bought a set of Cartman boosters recently. I like cables that remain flexible in cold weather and jaw clamps that grip firmly, my guess is I’ll have the years, but I’ll keep you updated, and if I like them, I’ll post a link on the “Small engine tools page.”

Connecting Jumpers

Battery poles are sometimes colored red for positive and black for negative. However, batteries will definitely be marked for positive and (-) for negative. You may need to clean the battery a little to find the markings.

Battery post markings – Look out for positive and negative markings on the battery casing.

Move your vehicle close to the mower and pop the hood to access the battery. You will likely have to remove a plastic shield from the car battery terminals.

Simply match the color and polarity of the leads. Always begin by fitting the Red jump lead to both battery poles first, but it’s all covered below. Just follow the sequence, and you’ll be mowing in jig time.

Jump Start Preparation Jumper Sequence

A ground source is any bare metal. There are always a ton of good places on the engine to clamp to. Clamping the final clamp to the battery negative pole isn’t advised. Doing so may cause arcing, which could ignite battery vapors. It’s a small risk, but it is possible.

Check – All modern mowers run a 12-volt system, and it’s perfectly OK to jump-start from your car. If you are unsure, check the battery casing, it will be marked 12 volts (V).

Tight – Mower blades and engines cause a lot of vibration, and bolts come loose from time to time. Check both connections. Positive red and negative black (-) are clean, tight, and in good condition.

Jumpers – Use good quality jump leads. These are my old worn-out ones.

Connect – Start by connecting the positive red of the mower (1) to the red of the car (2).

Now connect the negative black (-) on the car (3) to a ground (GRD) source on the mower (4). (Any bare metal will work)

Start – After starting the mower, allow it to run for a couple of minutes while still connected.

Remove the jumpers in reverse order, 4, 3, 2, and 1.

Mower Just Clicks

If you tried jump-starting your mower or the battery tested OK, then you may have a starter solenoid fault. These guys give lots of trouble, so it’s highly likely, but it’s not the only possible cause of the click sound. Check out this simple, easy-to-follow guide, we’ll test the solenoid, and I’ll show you the other common causes of the click sound – “Won’t start just clicks.”

Mower Won’t Start No Click

If you tried jump starting or the battery tested OK, but the mower makes no sound at all when you turn the key – You may simply have an open safety sensor, like not sitting on the seat or brake pedal not pressed, or you could have a more complex issue.

Anyway, I wrote a guide to help you find the problem. Check out all the most likely causes here “Mower won’t start – no click.”

How Long to Charge a Lawn Mower Battery [TipsTricks]

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It’s always annoying when you go to mow the lawn and your battery is dead. Or, even worse, when it dies halfway through and you have to recharge it.

So how long to charge a lawn mower battery?

How Long To Charge a Lawn Mower Battery On A Trickle Charge?

How long does it take to charge a lawn mower battery? The answer may surprise you – it depends on the size of your battery and the type of charger you are using.

Slow chargers, also known as Trickle Chargers, can take up to 24 hours to fully charge a single 12-volt Lawn Mower Battery.

Fast chargers will do the job in half that time or less. It is important to select the right charger for your needs because overcharging a lead acid battery will shorten its life.

Most home improvement stores sell both types of chargers; some even have models specifically designed for automotive batteries. You can also find them online from various retailers including Amazon.com

If this is your first time charging a lawn mower battery, we recommend starting with a slow charger until you get familiar with the process

The Charger You Use Matters

If you own a quiet lawn mower, then you know that one of the most important parts of keeping it running smoothly is to make sure the battery is always charged.

But how do you know how long to charge a lawn mower battery? Well, it depends on the charger you use.

riding, mower, battery, voltage


The voltage of your charging system should match the voltage of your lawn mower battery.

Most standard batteries are 12 volts, so if your charger is also 12 volts, then charging will be simple and straightforward.

If not, then you may need an adapter in order to connect them properly.


The amperage rating on your charger should be at least as high as the number printed on your lawn mower battery.

This number represents how much current (in amps)the charger can provide safely without damaging either itself or the battery where from 50-75% (of maximum capacity).

Anything below this risks overcharging which could damage or shorten lifespan significantly!

Useful Features:

Some features available with certain chargers can include things like automatic shut off once full power has been reached to prevent overcharging, digital displays showing progress/status, built-in temperature sensors for safety.

These often come at slightly higher price points but offer greater convenience peace of mind.

How Can You Charge A Lawn Mower Battery Properly?

It is always important to follow basic safety guidelines when handling or working with batteries. This includes understanding how to properly charge a lawn mower battery.

The first step is to locate the battery. Once you have found the battery, connect the positive and negative charging cables.

The next step is to allow the battery to charge for an appropriate amount of time before disconnecting the charger.

Finally, once you have finished charging the lawn mower battery, be sure to disconnect the cables in the reverse order that you connected them.

I eat a healthy balance of homegrown vegetables and beer. I live in Michigan with my wife and 3-year-old son, who both love and tolerate me!

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Important Specifications of Lawn Mower Batteries

Continuing the previous section’s discussion, let us see some important parameters and specifications of typical lawn mower batteries.

Type of Battery

As we mentioned before, you can find both lead-acid and lithium batteries for lawn mowers. In the case of lead-acid type, you again have flooded, AGM (Absorbent Glass Mat), and Gel types. Each type has its advantages and disadvantages.

Lithium batteries or Lithium Iron Phosphate to be specific, are also becoming quite popular with lawnmowers. The charging and protection methods (or lack thereof) are very different between lead-acid and lithium batteries.

Lead acid batteries are affordable, heavy, and robust to operate in all climatic conditions. But the problem is you have to take care of them and make sure they are fully charged all the time. Speaking of charging, the number of times you can charge and discharge a lead-acid battery is very less.

Lithium Batteries on the other hand are expensive and lightweight. Even though they support a good number of charge/discharge cycles, they need special circuitry in the form of a Battery Management System or BMS to protect the individual lithium cells from overcharging, deep discharging, etc.

Charging lead-acid and lithium batteries is very different. You can get chargers that support both these battery types but double-check the capabilities of the charger before using. Do not blindly use one type of charger on the other type of battery.

If the lawn mower has an alternator (which is usually the case with riding-type lawn mowers and lawn tractors), it can charge the battery once the engine is on. But for smaller mowers, this is usually not the case. You have to charge the battery externally.

Size and Other Physical Parameters

Physically, lawn mower batteries are smaller. In the next section Lawn Mower Battery Size Chart, we will see the dimensions of some popular types of lawn mower batteries.

Another important “physical” aspect of lawn mower batteries is the terminals and their position. Unlike car batteries, which usually have a pretty standard type of terminals, mower batteries have more than one type of terminal to connect the cables.

Also, the position of the terminals might be different between brands, manufacturers, and battery types. Usually, in a particular battery group, the type of terminals and their position (which is almost always on the top) will be common.

But we cannot say the same when you go to a different battery group.


The reason why we are talking about battery voltage is in the early days of lawn mower batteries, we used to get them in 6V ratings as well. But it is safe to assume that most modern mower batteries that we get today are 12V batteries.

This applies to both lead-acid and lithium batteries. So, all the batteries we are going to discuss in the guide are 12V unless otherwise mentioned.


The capacity of a starter battery is an interesting specification. It represents the amount of current in amps a fully-charged battery can deliver for 10 hours straight.

We usually see the battery capacity specification as Ampere Hour or Ah. Depending on the size of the battery, its capacity can range anywhere between 10Ah to 40Ah.

riding, mower, battery, voltage

Cold Crank Amps (CCA)

This is one of the important specifications of a starter battery, be it for cars or lawn mowers. What does CCA mean? Cold Crank Amps or CCA represents the amount of cranking current (in amps) a fully-charged battery can deliver for a period of 30 seconds at a temperature of 0°F.

As the size of the gas engine in mowers is small, you don’t need a large cranking current to start the engine. Hence, you will see CCA ratings of mower batteries in the range of 100A to 300A. You can find batteries with CCA ratings more or less than this range. You have to check your lawn mower’s manual as it will usually recommend a specific CCA value.

Lawn Mower Battery Size Chart

An important thing to remember before purchasing a new mower battery is they are significantly smaller than car batteries and within lawn mower batteries we have several sizes.

A Battery Group categorizes the physical dimensions of the battery. All the batteries falling in a particular group have nearly identical shapes and sizes. If you are familiar with car and boat batteries, there are we have several battery groups.

Let us now see some popular lawn mower battery groups. The groups in this list are no way near the full possible types but these are pretty common with mowers.

The following table is a Lawn Mower Battery Size Chart consisting of the common battery groups.

How To Choose a Replacement Lawn Mower Battery?

The common thing between a gas-powered lawn mower and a car is they both have engines. But we take cars very frequently to school, work, shopping, or other commuting activities.

This is not the case with lawn mowers. We use them only when we need to mow the lawn or garden. So, for the most part of its life, a lawn mower usually sits in a garage or shed.

Here comes the problem. As we take our cars out for a spin on a regular basis, the level of discharge of the car’s starter battery won’t be that bad. But as lawn mowers are sitting idle most of the time, there is a good chance that the battery will discharge pretty quickly.

If you have an external charger, then you can extend the life of the lawn mower battery. But in case you don’t have a battery charger, then you will at a replacement in a short time.

Things to Consider for Lawn Mower Battery Replacement

The first and most important thing while choosing a new lawn mower battery is to check the physical dimensions of the battery. Lawn Mowers have a slot for the battery that fits only one type of battery.

When we say one type, we mean one size. The replacement battery must fit perfectly into that slot and it should be loose (and if it is tight, you can’t even fit the battery into the slot).

So, check the owner’s manual or maintenance guide of your lawn mower and look for battery specifications. If they mention the battery group, then you can simply browse for that particular group and purchase a replacement.

What if you can’t find the battery group information? We have to old school and measure the dimensions of your current battery. With this information, you can look up any lawn mower battery size chart and compare the dimensions with the common and popular battery groups in the list.

After the battery group size, the next important specification is the CCA rating of the battery. Once again, check the user manual if they specify the necessary CCA of the battery. If not, look at the label of the current battery and you might find the CCA ratings.

When shopping, you need to match the CCA values. It can be higher than the current value, but never lower. But if you opt for a higher CCA rating, then you have to spend more money.

Another important thing is the type of battery. We have lead acid and Lithium Iron Phosphate as the two base battery types. Further, in lead-acid, we have wet or flooded, AGM, and Gel types.

Always choose a replacement battery of the same type as your current battery. The compatibility between different battery types is, to put it in simple terms, highly questionable.


If you have a lawn or garden, then you have to invest in a decent lawn mower. It does the job of shearing or cutting the grass and maintaining it at a set level very easily.

Like many power tools, even lawnmowers come in different shapes, sizes, and power options. The most common and popular one is the gasoline engine-powered lawn mower.

Pull-starting the gas engine of the lawn mower is an old technique. Nowadays, most lawn mowers come with electric starters. When we say electric starters, it means there is a battery involved in it.

If the battery is old or dead beyond recharging capabilities, then you have to look for a replacement.

In this guide, we saw the basics of lawnmowers and their types. Then we moved to different types of lawn mower batteries and also some important specifications you need to consider while looking at mower batteries.

riding, mower, battery, voltage

After that, we made a simple lawn mower battery size chart. This chart consists of some popular lawn mower battery groups with their physical dimensions.

We hope that this guide on lawn mower battery size chart could help you understand the basics of lawn mower batteries and also in making an easy purchase decision.

If you feel we missed something or want us to add anything, do let us know in the Комментарии и мнения владельцев section below. If you want, we can add lists of possible replacements in several battery groups (for instance, all the best replacement batteries for the U1 or U1R battery group).


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