Do New Lawn Mower Batteries Need to Be Charged. Battery for lawn mower

Do New Lawn Mower Batteries Need to Be Charged?

Battery-powered lawn mowers have come a long way to be a viable alternative to their gas-powered counterparts. Lithium-ion batteries, which are typically used to power these machines, are able to be charged quickly, have a high capacity, and are capable of putting out a lot more power than older style power tool batteries, and as a result, they’re able to power a lawn mower. Do new lawn mower batteries need to be charged? Usually, electric walk-behind lawn mower batteries have enough charge to use out of the box. However, this isn’t necessarily standard, and you may open the box for your new mower and find that the battery isn’t fully charged or isn’t charged at all. Riding lawn mower batteries don’t need to be charged at all, since they are standard 12-volt batteries similar to the ones found in cars. In most cases, push mowers that are powered by a batter will have at least some charge in them when they leave the factory, though this isn’t always the case. One of the biggest benefits of modern lithium-ion batteries, however, are their extremely fast charge time. Read on to find out all about lawn mower batteries!

Do New Lawn Mower Batteries Need to Be Charged?

If you purchase a new push mower that’s equipped with a battery, you can expect the battery to have at least enough charge to get it started and mow a small patch of grass. It may not be fully charged, especially if it’s been some time since it came from the factory. Of course, there’s always the chance that it has no charge in it. Your riding mower should have a charge when you take ownership of it. Even though it can lose its charge after two or four weeks of going without a start, the store you purchase it from should be running it from time to time. If you buy a riding mower that has a dead battery the first time you purchase it, you should reach out to the seller or manufacturer.

What Sort of Battery is in a Lawn Mower?

The battery that’s in a lawn mower depends on the type of lawn mower. Push mowers that run on batteries typically have a Li-Ion battery of varying voltages, and is made by the same manufacturer as makes the rest of the mower. Riding mowers have a 12-volt battery that’s similar to the ones found in cars, albeit on a smaller scale.

Push Mowers

  • They can’t hold as much of a charge
  • They don’t provide as much power as an Li-Ion battery
  • They take significantly longer to charge.

This means mowing an acre of land might take several hours because you would have to wait for the battery to charge several times while mowing, or else have replacement batteries.

An NiCD battery that put out enough power for a lawn mower would also likely be very large. However, Li-Ion batteries hold a lot of power in a small space and are able to be charged very quickly.

This means that the top of the line push mowers with Li-Ion batteries are able to cut over a quarter acre on one single charge.

Another cool feature of many modern battery-powered push mowers is the fact that they vary the amount of power drawn based on the grass resistance.

Therefore, different areas of your lawn may require different power outputs. This feature extends battery life and allows you to cut larger areas on a single charge.

Riding Mowers

Riding mowers are powered by large 12-volt, lead-acid batteries like those found in your automobile. These batteries are solely intended to start the mower’s engine.

When these batteries are brand-new, they don’t need to be charged at all, and running the engine helps build back up the charge that’s used in starting the machine. However, 12-volt batteries do lose charge as they age, and they become less able to hold a charge as well.

If your riding mower won’t start and you have to jump it constantly, you may have to replace the battery.

How Do You Take Care of a Li-Ion Battery?

Li-Ion batteries have a number of considerations to extend the battery life. Unlike NiCD or NiMH batteries, you don’t need to fully deplete them before recharging.

However, you shouldn’t overcharge the battery, as this will shorten its life. Li-Ion batteries can hold a charge for months, so that isn’t something to worry about either. In general, you should charge Li-Ion batteries as soon as you’re done with them, being careful to remove them from the charger as soon as they’re charged.

Some of the newer batteries out there have chargers that prevent overcharging, but you should always check the user manual to make sure that this is the case.

Do You Ever Have to Jump-start a Riding Mower Battery?

Anyone with a car has likely had to jump start their battery at least once in their life. The same is true for a riding mower, which has a similar engine to (albeit a much smaller one) and the same kind of battery as a car.

The battery in a riding mower is part of the ignition system, which helps to get the engine started. However, there are a number of reasons your riding mower battery may be draining:

  • Key is left in the “on” position and drains the battery
  • Battery is corroded around the posts
  • It’s been a long time since you last started it, and the battery has lost charge
  • Your lawn mower has a bad charging system and the battery isn’t recharging during operation

Having to jump-start a riding mower can be an annoying hassle, especially if you store it in a place where you can’t get your car to.

If you want to learn more about jump starting or charging a lawn mower, check out this article I wrote about this subject.

Closing Thoughts

When you purchase a new battery-powered lawn mower, the battery inside likely has at least some charge on it. Li-Ion batteries can hold a charge for months at a time, so as long as the manufacturer charged it before it went in the box, you’re probably good to go.

However, you may open it up and find that you need to stick it on its charger for a short time to mow your lawn; luckily it won’t be a long wait.

If your new riding mower battery needs a charge, on the other hand, you should reach out to the store you purchased it from or the manufacturer for help.

These 12-volt lead acid batteries should work when you purchase them, so if they aren’t working, you probably want to try and get a replacement one. A battery experiencing those sorts of issues right out of the box will probably give you a lot of trouble down the road.

Hi! I’m Peter, the owner of BackyardGadget. Working around the house has always been a big part of my life. I’ve created this site to share my experience, and to help people choose the right tools for the job. Thank you for stopping by!

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Hi! I’m Peter, the owner of BackyardGadget. Working around the house has always been a big part of my life. I’ve created this site to share my experience, and to help people choose the right tools for the job. Thank you for stopping by!

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Because East Penn has built more than 250 quality control checks into the manufacturing process, Outdoorsman batteries guarantee superior performance – every time.

Lawn Garden Batteries:

Learn more about East Penn’s battery selection for lawn garden:

Deka Outdoorsman Batteries

The Outdoorsman battery delivers plenty of cranking amps to power tractors and small-engine recreational vehicles across the roughest terrain.

  • Electrical short prevention system protects power-producing components from life-robbing electrical shorts
  • Vibration-resistant design with reinforced posts, straps, and welds withstand demanding conditions
  • Power-Perform full-framed plates better withstand severe service demands while optimizing current transfer
  • Tough polypropylene case and cover resist external damage from tough outdoor use
  • Side, safety vent system prevents acid leaks up to a 45° tilt, keeping battery dry and corrosion-free

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With over 90 warehouses and distribution centers in North America, East Penn is here to service your delivery and core return needs through one powerful network.

Whether it’s store-door or direct delivery programs, our network of company-owned and operated facilities and premier sales and service staff delivers the industry’s leading logistical support and highest customer satisfaction levels.


East Penn is one of the only battery manufacturers to make all types of flooded, AGM (Absorbed Glass Mat), and Gel technologies. This gives customers a powerful choice and reliable information source for these lead-acid battery products.

We also offer the exclusive UltraBattery and Synergy technologies for partial state-of-charge transportation applications. UltraBattery technology combines the advantages of an Advanced VRLA battery with the advantages of an asymmetric supercapacitor, while our Synergy battery technology offers one of the most cost-effective solutions that is ideal for Micro or Mild HEVs.

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Why are East Penn’s Power-Perform Ⓡ Plates more efficient than other plates? The plate plays a critical role in the performance of the battery’s overall power system. The ability of the plate to store and deliver power is directly proportional to how well it supports the vehicle’s power needs. Power-Perform Plates perform these functions with the highest efficiency enabling more power-per-space and better overall performance. Full-frame structure provides better current transfer from all sides of the plate Enhanced crystallization of the active material and specially formulated oxide optimizes energy storage for high-powered performance Low resistance current path grids with more top frame intersecting wires allow the direct flow of energy for greater starting power Revolutionary paste adhesion techniques deliver better performance over extended use

How do East Penn’s Power-Perform Plates Ⓡ perform better while lasting longer? Power-Perform Plates work within an overall battery life protection system and an advanced durability design to extend performance and service life. Increased grid frame tensile strength resists plate growth to safeguard against life-threatening shorts Thicker backweb and puncture resistant separators prevent plate-to-plate electrical shorts Ultra-pure electrolyte with no impurities inhibits unnecessary water loss Full-frame plate structure prevents exposed wire electrical shorts Advanced battery formation controls prevent high temperature damage and under-formed, low-performance plates Precision craftsmanship, stringent testing, and consistent performance and quality analysis through advanced centralized laboratories ensure that Power-Perform Plates deliver optimized life, power, and durability, even under the most severe service. This means lower warranty claims due to less defects combined with better and longer battery performance.

AGM (Absorbed Glass Mat) TECHNOLOGY

What is AGM? AGM stands for Absorbed Glass Mat

What is an Absorbed Glass Mat? A highly absorbent, micro-porous mat made of special glass fibers. The specially designed mats are an essential component in the battery’s electrolyte suspension system. All of the electrolyte is absorbed into this material enabling a spillproof design.

Why buy an AGM battery from East Penn? East Penn is a pioneer in developing the Form, Fit, and Function of AGM battery technology. The company’s engineering design and manufacturing process meets major US and European OE automotive manufacturers’ standards. From the company’s use of the finest raw materials to precision-focused manufacturing (like the weighing and thickness analysis of every battery group), East Penn’s AGM battery design and process has been tested and proven to best meet the Form, Fit, and Function criteria of the automotive industry.

Are AGM batteries OK for any application? AGM batteries will replace a flooded battery in any typical alternator voltage regulated system. These systems generally maintain a voltage at 13.8 to 14.4 volts (cars, trucks, commercial trucks, boats, etc.). In fact, the efficient recharging of the AGM battery design can cause less wear on the vehicle’s alternator system over time.

Can AGM batteries be recycled like conventional flooded batteries? AGM and conventional flooded lead-acid batteries are one of the most recyclable products on the planet. Lead-acid batteries have a higher recycling rate than glass, aluminum, and newspaper. In fact, virtually 100% of every battery component can be recycled to make a brand new battery. East Penn operates one of the most modern and environmentally-safe facilities in the world. This enables our customers to assure their customers that they are recycling their batteries with someone they can trust.

Is AGM really a premium battery product? Yes. This advanced AGM technological design offers superior performance over conventional flooded batteries. All automotive batteries are expected to meet a certain level of performance standards for engine starting and to provide reserve power for the vehicle’s electronics. AGM batteries, however, are expected to excel in certain key aspects of battery use such as:


As the electrical, high heat, severe service, and durability demands continue to intensify for today’s vehicles, conventional flooded batteries may not deliver the dependable performance and service life needed under these conditions. This is not only the trend for cars and trucks, but now commercial trucks, marine vessels, and power sports vehicles are requiring a more evolved type of battery power.

CYCLING PERFORMANCE Why do customers need better cycling performance from their batteries? Today’s vehicles, and those to come, are being built with more factory-installed electronics and more places to plug in portable devices. For example, cars and other passenger vehicles have to provide power for items like LCD viewers, GPS systems, stereos and speakers, powered Windows or doors, cell and Smart phone charging, and anything else that plugs in or turns on. Boats need power for accessories like live-wells, GPS systems, stereos, hazard lighting, fish finders, and any other item that plugs in or turns on. Cars that utilize stop/start functions, like Micro Hybrid Electric Vehicles, demand extra durability and a better charge acceptance from their battery. As more types of electric vehicles evolve, so will the need for a higher cycling tolerance from the battery.

How do AGM batteries help to deliver better cycling performance? AGM battery technology withstands these additional accessory power and cycling demands while still having the power to start the vehicle. An AGM battery’s enhanced durability and charge acceptance makes it an essential component for many stop/start and other electrical system technology. Its ability to have over twice the cycle life of a conventional flooded design gives it a clear advantage for its implementation into progressing electric vehicle technology.

SEVERE SERVICE DURABILITY Why do customers need better severe service durability from their battery? Severe service and higher temperature conditions continue to escalate because there is less open space under-the-hood with more demand on the battery. Also, more vehicles undergo stop-and-start driving conditions, further increasing the need for enhanced durability.

How do AGM batteries help deliver better severe service durability? AGM battery technology can be utilized to help offset these increasing power and durability demands. The AGM battery’s ability to withstand severe service and accessory power demands under elevated temperatures and stop-and-go conditions will better safeguard performance and extend battery life.

DEEP DISCHARGE RESILIENCY Why do customers need a better deep discharge resiliency from their battery? Vehicles that aren’t used everyday have a higher risk of not starting because of parasitic accessory power loads. Parasitic loads, or even leaving something on when the ignition is off, can completely drain the battery’s power.

How do AGM batteries help deliver better deep discharge resiliency? AGM battery technology delivers a higher deep discharge abuse tolerance. This helps protect the battery longer from situations like infrequent use, parasitic power drains, or other deep power discharge (like leaving your vehicle’s lights on when the ignition is off).

VIBRATION RESISTANCE Why do customers need a battery that resists vibration damage? Vibration resistance is extremely important to protecting the battery’s life in almost any application that moves. Vibration or jolting movements can lead to electrical shorts or the loss of electrical storage capacity that can significantly decrease the battery’s performance.

How do AGM batteries help deliver battery vibration resistance? AGM technology utilizes an Absorbed Glass Mat that protects the battery’s internal components. These special separators serve as a shock absorber to the battery, which buffers vibration or other potentially damaging movement. This added vibration protection is especially ideal for off-road vehicles, watercraft, performance cars, tuner cars, or any other vehicles that undergo intense vibration during normal use.


What is Cycle Life? A CYCLE is a single occurrence when energy is taken out of the battery and then put back in. CYCLE LIFE is the ability of the battery to do that over and over again and continue to deliver reliable performance.

How does claims of extended CYCLE LIFE differ from claims of just extended battery life? LIFE vs. CYCLE LIFE Claims that a battery has extended LIFE could simply mean it survives longer than average in a typical automotive application in an average climate. In the real world, actual battery life is highly variable and unpredictable. The stresses on a battery differ by climate, vehicle differences, and user habits. A battery may last a long time under ideal conditions, but fail with only minimal abuse.

A battery with extended CYCLE LIFE survives longer than average under more grueling demands that portray a more realistic picture of real world use. This includes warmer climates, higher under-hood temperatures, longer than typical hours of usage, higher annual miles of operation, and frequent electrical loads while the engine is off.

Why do customers need better cycling performance from their batteries? Today’s vehicles, and those to come, are being built with more factory-installed electronics and more places to plug in portable devices. For example, cars and other passenger vehicles have to provide power for items like LCD viewers, GPS systems, stereos and speakers, powered Windows or doors, cell and Smart phone charging, and anything else that plugs in or turns on. Boats need power for accessories like live-wells, GPS systems, stereos, hazard lighting, fish finders, and any other item that plugs in or turns on.

Newer cars are also utilizing additional electronic functions in areas that were traditionally powered by the engine. This is not only the case for Hybrid Electic Vehicles, but is also being incorporated throughout a variety of standard automotive designs. These additional electronic services demand extra performance from the battery. As more types of vehicles evolve further into electrification, so will the need for the higher cycling tolerance and overall durability in a battery that can be found in the AGM design.

How does East Penn’s AGM product have extended CYCLE LIFE? East Penn’s AGM batteries have special glass mats that are strategically wrapped around the battery’s power producing components. The main reason for this mat is to absorb all the battery’s acid so the battery won’t leak or spill if turned over or if cracked. However, these mats also provide an added layer of protection for these components. This added protection enhances the battery’s durability against continual power drains like electronics. In fact, East Penn’s AGM batteries have 2x the cycle life over traditional maintenance-free flooded batteries to power more accessories for much longer. This enhanced durability also protects the battery from vibration, high temperatures, the rigors of stop-and-go driving and frequent vehicle use.


What are VRLA batteries? Valve-Regulated Lead-Acid or VRLA, including Gel and AGM (Absorbed Glass Mat) battery designs, can be substituted in virtually any flooded lead-acid battery application (in conjunction with well-regulated charging). Their unique features and benefits deliver an ideal solution for many applications where traditional flooded batteries would not deliver the best results. For almost three decades, East Penn has been manufacturing valve-regulated batteries using tried and true technology backed by more than 65 years experience. East Penn produces a complete line of Gel, AGM, and conventional flooded products for hundreds of applications. This diverse product offering enables East Penn to be objective as to the advantages of each type of battery. East Penn’s VRLA (Gel and AGM) products have the reputation of being the highest quality VRLA batteries available.

How do VRLA batteries work? A VRLA battery utilizes a one-way, pressure-relief valve system to achieve a “recombinant” technology. This means that the oxygen normally produced on the positive plate is absorbed by the negative plate. This suppresses the production of hydrogen at the negative plate. Water (H2O) is produced instead, retaining the moisture within the battery. It never needs watering, and should never be opened as this would expose the battery to excess oxygen from the air. In addition to damaging the battery, opening it also voids the warranty.

What is the difference between VRLA batteries and traditional flooded batteries? Flooded electrolyte batteries do not have special one-way, pressure-relief valves, as they do not work on the recombination principle. Instead, flooded designs utilize a vent to allow gas to escape. They contain liquid electrolyte that can spill and cause corrosion if tipped or punctured. They should not be used near sensitive electronic equipment. They can only be installed “upright.” Flooded batteries lose capacity and become permanently damaged if: Left in a discharged condition for any length of time (due to sulfation). This is especially true of designs that require water maintenance. Continually over-discharged (due to active material shedding). This is especially true of automotive starting types.

What are ideal applications for VRLA batteries?

Deep Cycle, Deep Discharge Applications Marine Trolling Electronics Sailboats Electric Vehicles Wheelchairs/Scooters Golf Cars Portable Power Floor Scrubbers Personnel Carriers Renewable Energy Village Power (Solar, Wind) Marine RV House Power Commercial Deep Cycle Applications

Standby and Emergency Backup Applications UPS (Uninterrupted Power Systems) Cable TV Emergency Lighting Computer Backup Renewable Energy Frequency Regulation (Solar, Wind) Telephone Switching

Other Applications Race or High Performance Cars On-Highway Trucking Off-Road Vehicles Wet Environments Marine RV Starting Diesel Starting Cars and Light Trucks Vehicles with with Accessories Start-Stop Systems

What are Gel and AGM batteries? VRLA technology encompasses both gelled electrolyte or gel batteries and absorbed glass mat or AGM batteries. Both types are regulated by special one-way, pressure-relief valves and have significant advantages over flooded lead-acid products.

AGM (Absorbed Glass Mat) batteries The electrolyte in AGM batteries is completely absorbed in separators consisting of matted glass fibers. This causes them to be spillproof, meaning they don’t leak acid like a flooded design if tipped on their side. The glass mats in AGM batteries are wrapped around the positive plate, which helps prevent damage from vibration and extend cycling. The battery’s groups are packed tightly in the case partitions also protecting its power producing components. AGM battery designs can have over twice the cycle life of a conventional flooded product in the right application.

Gel or Gelled Electrolyte batteries The electrolyte in a Gel battery is permanently locked in a highly viscous gelled state instead of the traditional liquid form. Because there is no liquid-type electrolyte, it will not leak out of the battery if tipped on its side. The thick, gelled electrolyte and tightly packed groups also protect the battery’s power producing components. Gel battery designs have a superior deep discharge resiliency and can deliver over two to three times the cycle life of an AGM product in the right applications.

What are some similarities between Gel and AGM batteries? Batteries utilize special one-way, pressure-relief valves and must never be opened. Requires no electrolyte maintenance unlike deep cycle flooded batteries that require frequent checking and adjustment of electrolyte levels. Uses a recombination reaction to prevent the escape of hydrogen and oxygen gases normally lost in a flooded lead-acid battery (particularly in deep cycle applications). Spillproof design enables installation in virtually any position (upside-down installation is not recommended). Has a higher tolerance against damage from deep discharge. These batteries have optimized amounts of electrolyte (which is also referred to as “acid-starved”) so that they use the power in the acid before they use the power in the plates. This minimizes the destructive nature of ultra-deep discharges. Ultra-deep discharging is what causes plate shedding, which can destroy a battery.

What are the Major differences between Gel and AGM battery performance? A Gel battery is better suited for super-deep discharge applications, which means it can withstand deeper discharges without damaging the battery’s performance. However, due to the physical properties of the gelled electrolyte, Gel battery power declines faster than an AGM battery as the temperature drops below 32ºF (0ºC). AGM batteries excel for high current, high power applications and in extremely cold environments. AGM batteries deliver a better dual purpose solution for a combination of starting and accessory power.

What are the advantages of GEL and AGM battery designs? (waiting on image)

What do I need to know about VRLA battery charging? All lead-acid batteries release hydrogen from the negative plate and oxygen from the positive plate during charging. VRLA batteries have one-way, pressure-relief valves. Without the ability to retain pressure within the cells, hydrogen and oxygen would be lost to the atmosphere, eventually drying out the electrolyte and separators.

Voltage is electrical pressure (energy per unit of charge). Charge (ampere-hours) is a quantity of electricity. Current (amperes) is electrical flow (charging speed). A battery can only store a certain quantity of electricity. The closer it gets to being fully charged, the slower it must be charged. Temperature also affects charging. If the right voltage is used for the temperature, a battery will accept charge at its ideal rate. If too much voltage is used, charge will be forced through the battery faster than it can be stored.

Reactions other than the charging reaction also occur to transport this current through the battery—mainly gassing. Hydrogen and oxygen may be given off faster than the recombination reaction. This raises the pressure until the one-way, pressure-relief valve opens. The gas lost cannot be replaced. Any VRLA battery will dry out and fail prematurely if it experiences excessive overcharging.

Note: It is too much voltage that initiates this problem, not too much charge — a battery can be “over-charged” (damaged by too much voltage) even though it is not fully “charged.” Never install any lead-acid battery in a sealed container or enclosure. Hydrogen gas must be allowed to escape.

Can continual undercharging harm a VRLA battery? In many respects, undercharging is as harmful as overcharging. Keeping a battery in an undercharged condition allows the positive grids to corrode and the plates to shed, dramatically shortening life. Also, an undercharged battery must work harder than a fully charged battery, which contributes to short life as well.

An undercharged battery has a greatly reduced capacity. It may easily be inadvertently over-discharged and eventually damaged.

Do VRLA batteries have a “memory” like Ni-Cad batteries? One of the major disadvantages of nickel-cadmium (Ni-cad) batteries is that after shallow discharge cycles, the unused portions of the electrodes “remember” the previous cycles and are unable to sustain the required discharge voltage beyond the depth of the previous cycles. The capacity is lost and can only be restored by slowly discharging completely (generally outside the application), and properly recharging. VRLA lead-acid batteries do not exhibit this capacity robbing effect known as memory.

What are the safety precautions for VRLA batteries? Although all valve-regulated batteries have the electrolyte immobilized within the cell, the electrical hazard associated with batteries still exists. Work performed on these batteries should be done with the tools and the protective equipment listed below. Valve-regulated battery installations should be supervised by personnel familiar with batteries and battery safety precautions.

Protective Equipment To assure safe battery handling, installation and maintenance, the following protection equipment should be used: Safety glasses or face shield (Consult application specific requirements) Acid-resistant gloves Protective aprons and safety shoes Proper lifting devices Properly insulated tools

Procedures Consult user manual of specific application for safety operating requirements. The following safety procedures should be followed during installation: (Always wear safety glasses or face shield.) 1. These batteries are sealed and contain no free flowing electrolyte. Under normal operating conditions, they do not present any acid danger. However, if the battery jar, case, or cover is damaged, acid could be present. Sulfuric acid is harmful to the skin and eyes. Flush affected area with water immediately and consult a physician if splashed in the eyes. Consult MSDS for additional precautions and first aid measures. 2. Prohibit smoking and open flames, and avoid arcing in the immediate vicinity of the battery. 3. Do not wear metallic objects, such as jewelry, while working on batteries. Do not store un-insulated tools in s or tool belt while working in vicinity of battery. 4. Keep the top of the battery dry and clear of all tools and other foreign objects. 5. Provide adequate ventilation as regulated by Federal, State and Local codes and follow recommended charging voltages. 6. Extinguishing media: Class ABC extinguisher. Note: CO2 may be used but not directly on the cells due to thermal shock and potential cracking of cases. 7. Never remove or tamper with pressure-relief valves. Warranty void if vent valve is removed.

Can VRLA batteries be installed in sealed battery boxes? NO! Never install any type of battery in a completely sealed container. Although most of the normal gasses (oxygen and hydrogen) produced in a VRLA battery will be recombined and not escape, oxygen and hydrogen will escape from the battery in an overcharge condition (as is typical of any type battery).

These potentially explosive gasses must be allowed to vent to the atmosphere and must never be trapped in a sealed battery box or tightly enclosed space!

Does depth of discharge affect cycle life? Yes! The harder any battery has to work, the sooner it will fail.

The shallower the average discharge, the longer the life. It’s important to size a battery system to deliver at least twice the energy required, to assure shallow discharges.

Follow these tips for the longest life: Avoid ultra-deep discharges. The definition of ultra-deep discharge may vary with application and battery type. Don’t leave a battery at a low stage of charge for an extended length of time. Charge a discharged battery as soon as possible. Don’t cycle a battery at a low state of charge without regularly recharging fully. Use the highest initial charging current available (up to 30% of the 20-hour capacity per hour) while staying within the proper temperature-compensated voltage range.

What is a thermal runaway? The appropriate charge voltage depends on the battery temperatures. A warmer battery requires a reduced voltage. If the voltage is not reduced, current accepted by the battery increases. When the current increases, the internal heating increases. This can rise to destructive levels if not taken into consideration.

Thermal runaway can be prevented with: Temperature compensation monitoring at the battery —not at the charger. Limiting charging currents to appropriate levels. Allowing for adequate air circulation around the batteries. Using timers or ampere-hour counters. Using Smart chargers that recognize the signature of a thermal runaway event which will shut the charger down.

Symptoms of a Bad Lawn Mower Battery: Hard To Miss Signs

If you are curious about the symptoms of a bad lawn mower battery, the nyou are among the thousands of gardeners who have this question in their minds. The good news is that most symptoms are hard to miss, such as clicking noises and rotten eggs smell.

lawn, mower, batteries, need

In this complete guide, we will discuss all the symptoms that indicate that your battery might be struggling. Carry on reading because we will also discuss changing the electrolyte fluid in the battery to make it last longer.

  • What Are the Symptoms of Your Lawn Mower Battery Going Bad?
  • – The Engine Won’t Start
  • – Produces Clicking Sounds
  • – Produces a Rotten Smell After Some Use
  • – The Battery Loses Charge Quickly
  • – The Mower Refuses To Cut Grass
  • – The Battery Appears to Bulge
  • – Poor Fluid Levels
  • 1. Assess the Condition of Your Battery
  • 2. Conduct a Voltage Test
  • 3. Prepare the Tools You Need
  • 4. Remove the Battery First
  • 5. Clean the Battery
  • 6. Fill the Battery With Fresh Electrolytes
  • 7. Recharge the Battery
  • 8. Check the Connections

What Are the Symptoms of Your Lawn Mower Battery Going Bad?

The symptoms of your lawn mower battery going bad include the engine not starting, the mower producing clicking noises and a rotten egg smell, the battery losing charge faster than normal, the mower refusing to cut grass, and poor fluid levels.

It is easy to tell if your lawn mower’s battery has gone bad. Some classic tell-tale signs of such a battery are that the engine won’t start, produce clicking noises and produce toxic fumes.

– The Engine Won’t Start

The first tangible sign of a bad battery is when the mower won’t start on the first pull. Even more, multiple ignition turns might be needed to get the engine fired as the situation worsens. This means the engine does not have adequate strength to fire the spark plug.

After multiple tries, it does so feebly when the engine fires up. It will crank much more slowly than normal, sometimes not at all. However, the engine not starting can also be due to a faulty spark plug, ignition button, or alternator. Make sure to check these out to see that they are working properly before moving on to the battery.

– Produces Clicking Sounds

A lawn mower is not supposed to make unnecessary sounds while working, so if it starts producing clicking sounds when you attempt to turn it on, the battery is running low on power. Recharging it properly might solve the problem.

lawn, mower, batteries, need

Sometimes, the mower produces clicking noises and starts but does not turn over. This might mean that the battery is completely dead and in need of a replacement. When the lawnmower battery gets bad because of freezing and extreme weather conditions, this could cause problems with clicking and the engine starting without turning over.

– Produces a Rotten Smell After Some Use

A bad battery gets heated soon after use and produces toxic fumes. This is more pertinent for lead-acid batteries, where the sulfuric acid in the electrolyte gets turned into toxic fumes once the battery heats up.

In most of these cases, you will be able to smell hydrogen sulfide immediately because of its rotten egg smell. Be careful when touching the mower where the battery is located as it will be quite hot. Turn the engine off and let the mower cool down before doing anything else.

– The Battery Loses Charge Quickly

A lawn mower battery that either does not charge fully or stays charged afterward is going bad. Either the battery is too old or damaged, or there is something wrong with the charger.

With time, the battery’s capacity to hold charge does decrease naturally. After some years, you might notice having to charge it more often than before. However, if the battery is new or seems to be losing charge abnormally fast, then this is problematic.

If the battery refuses to charge altogether, in this case, your charger is faulty or the battery has gone bad.

– The Mower Refuses To Cut Grass

One uncommon and often ignored symptom of a gas-powered lawn mower’s battery going bad is that it will no longer be as efficient as before. It might work fine on thin, wispy grass, but as soon as you try to cut tall, thick grass, it will give up.

The battery is not strong enough to provide the engine with the power to cut through resistance. Check your blades to ensure there is nothing wrong with them, like a need for further sharpening. If they are okay, the battery is going bad and you need to fix it.

– The Battery Appears to Bulge

In riding mowers, the battery is usually located under the seating area and charged without taking it out of its box. That is why people often need to pay more attention to this vital symptom that the battery could be better.

When the engine stops turning off or producing clicking noises, take the mower’s seat off and take the battery out. It would help if you unscrewed some nuts and bolts here and there to loosen it. Notice the classic signs of battery wear down on all sides, including the bottom.

These signs include cracked edges, bulging sides, and blue-green corrosion on each battery terminal. Have a mechanic look carefully at this battery in case it becomes a health hazard.

– Poor Fluid Levels

Fluid levels within the battery are important indicators of a healthy vs. bad lawn mower battery. Check the fluid levels within each cell of the battery for this. In the case of lead-acid batteries, the electrolytes are a mixture of water and sulfuric acid.

Many things disturb the delicate balance of fluids within the electrolyte, such as overuse, overcharging, physical damage, or a battery that is too old. If the fluid levels within the battery are low, it is in an apt condition.

If the rest of the battery is in good condition, restoring the fluid levels will improve the battery. Buy a couple of bottles of distilled water and use them to get your battery working again.

How Do You Improve a Bad Lawn Mower Battery?

To improve a bad lawn mower battery, you should first assess the condition of the battery and conduct a voltage test. Prepare the tools that you will need and carefully remove the battery. Next, clean the battery and fill it with fresh electrolyte.

lawn, mower, batteries, need

Unless the battery is completely dead, you can help improve its condition by cleaning it and changing its electrolyte fluid. Instead of buying expensive fluid from the market each time, make your electrolyte at home using Epsom salt and distilled water.

Assess the Condition of Your Battery

Before deciding whether to change or repair the battery, assess it thoroughly. First, ensure that each cell is filled with the electrolyte until the line.

Then give the battery a detailed examination to see if it is corroded, cracked, leaking, or bulging from anywhere. If any of these symptoms are present, then it is better to discard them for a new one.

Conduct a Voltage Test

A voltage test will determine whether or not the lawn mower’s battery is dead. Most lawn tractors and lawnmowers use a 12-Volt battery to run them. A fully-healthy 12-Volt battery, when fully charged, will display a voltage of around 12.6 to 12.8 Volts.

In case of an older mower with a six-volt or lower battery will also display a voltage of six volts when it is completely charged. You will need a multimeter to check this voltage. If there isn’t one present at home, borrow it from someone or order one online as they are pretty cheap.

Attach the multimeter to the battery and set it at DC at 13 volts. The meter’s red lead should be attached to the battery’s positive terminal, while the black lead goes to the negative terminal. The battery has gone bad if the meter reads less than 12.3 volts. If the voltage comes out fine, then proceed to the next step.

Prepare the Tools You Need

Use your safety goggles, full-sleeved clothing, and thick rubber gloves when dealing with the lawn mower engine and battery. Make sure your battery charger is functional, automatic, and has an in-built voltage regulator.

Find baking soda and distilled water at home or in your local supermarket. A plastic funnel is also a must-have item. Epsom salt (magnesium sulfate) is the last ingredient you will need.

Remove the Battery First

Turn the engine off, pull out the keys, and disconnect the spark plug. Around 90 percent of riding-style mowers have batteries under the driver’s seat. Pull up the seat, loosen the screws holding the battery in its chamber, and carefully pull it out.

For any other type of mower, consult the instructions manual to see where the battery is located. Disrupt the negative and positive terminals to remove the battery from its chamber first.

There will be caps on each battery cell which need to be removed. Usually, they will be located right on top of the battery and easily come off. Otherwise, a small flathead screwdriver will help you uncap the battery.

Clean the Battery

If the battery terminals have bluish-green corrosion, clean them first. A corrosion-cleaning solution with sandpaper will help clean the discoloration. The next step is to drain out all the existing fluid from the battery.

The insides of the battery need to be cleaned from sulfate buildup over the years. Measure 10 ounces of baking soda and dissolve it in one whole gallon of distilled water. Using the funnel, pour this solution into the empty cells of the battery and put their caps back on.

Now shake your battery thoroughly and leave it for a minute or two, then drain the solution out using the same funnel. Make sure you wear the thickest rubber gloves you have because these solutions can burn the skin.

Fill the Battery With Fresh Electrolytes

Now that it is clean, your battery needs fresh, new electrolytes added to it. You can buy electrolytes premade or make it yourself at home. It is simple, and you only need to add 15 ounces of Epsom salt to one gallon of distilled water.

Warm the water a little bit first, so the salt dissolves quickly. Again, the funnel will be helpful while pouring the electrolyte into each battery cell. There is a line on each cell until you fill it. Be mindful that you don’t overfill or underfill the battery. Screw the caps back on each cell, and your battery is ready.

Recharge the Battery

Next, it’s time to recharge your newly filled battery for the first time. Always use automatic chargers with adjustable settings options for charging.

Set the charger to the slowest charging option, around two amperes per 24 hours. Yes, it would help if you gave the battery at least one whole day to become charged. During this time, keep the caps on individual cells slightly loose for any potential outflow of the charge.

Once the battery is charged to 100 percent, tighten the cell caps. Carefully place the battery back in its place within the mower. Attach the positive terminal and then the negative one when connecting the battery to the mower.

Check the Connections

Before restarting your newly charged battery again, check that all its connections with the engine are correct and secure. The negative and positive terminals should be attached properly to their required connections. If broken or damaged, the cables will not let the engine start, so it is better to replace them.

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Before we conclude this article, here are the most pertinent points regarding a bad mower battery.

  • The first sign of a bad battery in the mower is that the engine will have a harder time starting and producing sounds while working.
  • Bad batteries lose charge rapidly and need frequent recharging. They also produce toxic gases and fumes, such as hydrogen sulfide, that smell like rotten eggs.
  • A bulging, cracked, or leaking battery is also symptomatic and needs to be replaced immediately.
  • If the battery is not dead, then take it out, clean it, and replace its electrolyte with a fresh one.

When the mower battery gets old, you must be careful about potential symptoms if it doesn’t work as well as before. This would ensure that you improve its condition or change it before it becomes a potential health hazard.

Make the switch to a greener yard with a high-performance battery-powered lawn mower.

By Tony Carrick and Mark Wolfe | Updated Apr 17, 2023 5:30 PM

We may earn revenue from the products available on this page and participate in affiliate programs.

lawn, mower, batteries, need

Whether you’re switching from gas-powered to green or buying your first cordless electric mower, battery-powered lawn mowers offer many advantages. In addition to being kinder to the environment, they’re also quieter and easier to start than gas-powered mowers.

These innovative machines use powerful batteries that provide enough juice to mow lawns up to a half acre or larger. They also produce enough torque to cut through tall grass and many are self-propelled, making them easier to operate.

We tested the following battery-powered lawn mowers in different grass-growing environments to find out more about their capability, reliability, and overall user comfort. Read on to learn about the important features to consider, how to select the best battery-powered lawn mower for areas ranging from just a few square feet to a couple of acres, and how each mower performed in our hands-on tests.

  • BEST OVERALL:Snapper XD 82V MAX Cordless 21-Inch Self-Propelled Mower
  • BEST BANG FOR THE BUCK:Greenworks Pro 80V 21-Inch Cordless Lawn Mower
  • BEST SELF-PROPELLED:Toro Flex Force 60V 21-Inch Super Recycler Mower
  • BEST RIDING:Ego Power Z6 42-Inch Zero Turn Riding Mower
  • BEST FAST-CHARGING:Ego Power 21-Inch Select Cut Lawn Mower
  • BEST FOR LARGE YARDS:Greenworks 40V 21-Inch Smart Pace Lawn Mower
  • BEST FOR SMALL LAWNS:Worx Nitro 80V Power Share 21-Inch Self Propelled Mower

lawn, mower, batteries, need

How We Tested the Best Battery-Powered Lawn Mowers

Battery-powered lawn mowers generally offer a quiet, exhaust-free mowing experience. They remove the hassle of buying and hauling gasoline, changing oil, and other maintenance aspects of gas engines. With the notable exceptions of sharpening/replacing blades and charging/replacing batteries, they are virtually maintenance-free. While shoppers are motivated to buy battery-powered lawn mowers for a multitude of reasons, the expectation remains that they will be able to mow their grass whenever they want, without hassle or frustration. To us, as testers, that meant we needed to closely scrutinize runtime, recharge time, and overall mowing capability.

We tested all mowers the same way and captured the results on a testing rubric for comparison. After fully charging the batteries, we used them to mow two different areas, one that had been consistently maintained at the normal mowing height, and one that had been neglected and allowed to grow about 10 inches high. Both areas included a mix of flat and moderately sloped ground. As we mowed, we assessed general operator comfort, self-propelled capabilities, mowing power, and finished mowing quality. We mowed until the batteries ran out, recorded the runtime, and measured the area mowed. Finally, we recorded the time required to recharge the depleted batteries.

Because riding mowers offer many more features and control options, we tested the Ego Power Z6 over several days with multiple battery configurations. Battery life plays such an outsized role in overall performance and customer satisfaction that we wanted to collect results on maintained and overgrown grass for groupings of two, four, and six batteries. The testing criteria and observation points for each test run were virtually the same as those for the other mowers. The great news is that all of these mowers delivered excellent mowing power, good-to-excellent cut quality, and plenty of runtime for real-world applications as shown in the individual reviews.

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Our Top Picks

We tested the following mowers taking into account the above considerations for large and small yards. Read on to learn how each model performed in testing and why we consider them among the best battery-powered lawn mowers.

Snapper XD 82V MAX Cordless 21-Inch Self-Propelled Mo

The Snapper XD features a variable-speed transmission and design features that allow for adjustments to meet different grass-cutting demands. The StepSense feature automatically adjusts the speed to match the user’s walking pace. Load-sensing technology in this model automatically adjusts power output based on the thickness of the grass to provide a clean cut while maximizing energy efficiency.

The mower’s impressive 21-inch steel cutting deck is versatile. It boasts seven height adjustments that are easily changed from behind the mower with a single lever. The deck can mulch, side discharge, or bag with a capacity of up to 2.1 cubic feet of grass clippings.

When the yard work is done, this mower folds up conveniently for vertical storage in the garage. The kit includes two 2.0-Ah (amp hour) batteries, which together provide about 60 minutes of runtime and recharge in about 60 minutes.

In our tests, the Snapper XD traversed all types of terrain and left behind a smooth, even cut on a single pass. It easily powered through overgrown grass and weeds up to 10 inches tall, although extended use in tall weeds increased the needed power output and reduced runtime by about half.

We were more impressed by the blade motor’s load responsiveness than by the automated pace-adjustment system. The StepSense feature worked well on relatively flat ground, but on inclines it felt somewhat sticky or uneven. In overall performance for the price, this mower offers excellent power and runtime to mow about ⅓ of an acre, or 15,000 square feet, per charge.

Product Specs

  • Runtime/recharge time: 60 minutes/60 minutes
  • Deck size: 21 inches
  • Mobility: Self-propelled, automatic pace adjustment
  • Automatically adjusts to any individual user’s pace
  • Powerful motor doesn’t bog down in dense grass
  • Single lever cutting-height adjustment for user-friendliness
  • Folds into a compact unit for ease of storage
  • Less runtime per charge than some competitors
  • StepSense feature feels somewhat “sticky”

Get the Snapper battery-powered lawn mower at Appliances Connection, Amazon, Lowe’s, Mowers Direct.

Greenworks Pro 80V 21-Inch Cordless Lawn Mower

Greenworks is known for its advancements in battery technology, and this model has two 2.0-Ah batteries that allow for up to 70 minutes of runtime from a full charge, with a combined recharge time of just 60 minutes. This push mower features a 21-inch-wide mowing deck. Technology that adjusts the motor speed based on load helps to maximize battery life and maintain excellent cut quality.

Adding to this impressive mowing coverage is a steel deck with seven positions that are easy to adjust with a large handle near the right rear wheel. Its sturdy steel deck gives it the tough feel of gas-powered models.

A large start button and easy-to-maneuver speed control mean it can be manipulated with gloved hands. This push mower does not have motorized wheels, which keeps the price low and maximizes battery life for cutting grass. The 3-in-1 grass clipping capability allows for bagging, mulching, or side discharging, and a foldable handle design facilitates compact storage.

Although this Greenworks push mower required a bit more effort to move around the yard than the self-propelled mowers, its simplified design made it an extremely capable mower. The powerful motor offered the most “gas-like” performance of the group. It had no trouble cutting dense, weedy grass up to 10 inches tall and left possibly the best finish of all the mowers we tested. In all three modes, bagging, mulching, and side discharging, it left the grass perfectly smooth, with no uneven spots or stringy weeds left behind. It had plenty of power to mulch thick grass into virtually invisible clippings.

The only downside of this mower was that hilly ground reduced the amount of area mowed per charge, not because of demand on the mower, but because the operator’s pace slowed. Everything else considered, we felt that this push mower delivered the strongest mowing capability, even though we had to push it. And the price was significantly less than the others.

Product Specs

  • Runtime/recharge time: 70 minutes/60 minutes
  • Deck size: 21 inches
  • Mobility: Push
  • Dual 2-Ah batteries offer up to 70 minutes of runtime; ideal for both small and large yards
  • Strong motor delivers powerful cutting performance; ideal for thin and thick grass varieties
  • Easy to use controls integrated into the handle
  • Included charger only charges one battery at a time
  • Not self-propelled; may cause some strain on the user

Get the Greenworks 80V battery-powered lawn mower at Amazon or Lowe’s.

Toro Flex Force 60V 21-Inch Super Recycler Mower

The Toro Flex Force Super Recycler lawn mower is built for powerful mowing performance with superior operator comfort. The three-phase motor automatically increases power output when it detects tougher mowing conditions, then eases off to conserve battery life when the mowing gets easier again.

The 21-inch military-grade cast aluminum deck features a powerful vortex air-intake system that stands the grass blades up straight for a smoother, cleaner cut. The shock-absorbing Personal Pace self-adjusting, self-propelled system operates smoothly regardless of the terrain. Bright LED headlights make it easier to mow later into the evening. It comes with a powerful 60V 7.5-Ah battery that delivers up to 50 minutes of runtime per charge and recharges in 3 hours.

The Toro Super Recycler was the most comfortable battery-powered mower we tested, primarily because of its robust self-propulsion system. Although it was not the only mower with a pressure-sensitive handle, this one functioned the best. It paired the slightly more resistant, but buttery smooth, handle movement with a higher top-end speed for self movement that felt almost effortless on most terrain. Only slight pressure was required to climb the uphill areas, and it didn’t try to run away on the downhills.

Toro’s excellent cut quality was second only to the Greenworks 80V (mainly because the Greenworks mower performed exceptionally well in overgrown areas and Toro needed a second pass for best results there). However, we were underwhelmed by its battery performance at only 45 to 50 minutes of runtime in average conditions and 3 hours to recharge. Still, anyone with less than a half acre who is shopping for smooth operation and a top-quality cut may want to consider the Super Recycler.

Product Specs

  • Runtime/recharge time: 50 minutes/180 minutes
  • Deck size: 21 inches
  • Mobility: Self-propelled, automatic pace adjustment
  • Mows up to 0.4 acre (17,424 square feet) per charge
  • Self-propelled rear wheels
  • Motor automatically adjusts output to match mowing conditions
  • Lightweight, rust- and corrosion-resistant aluminum deck
  • LED headlights allow for ample visibility or nighttime mowing
  • Longer recharge time than the competition
  • Top mowing speed is too fast for imperfect conditions

Get the Toro battery-powered lawn mower at The Home Depot.

Ego Power Z6 42-Inch Zero Turn Riding Mower

Those with larger acreage can now have a battery-powered mower that can actually cut all of their grass on a single charge. The Ego Power riding mower is capable of mowing up to 2 acres per charge, with easy upgrades that can increase runtime to cut more than 3 acres per charge. Plus, it offers many of the same features found on gas-powered zero-turn mowers, such as adjustable lap bars to independently control the rear drive wheels; heavy-duty front swivel casters; a comfortable high back seat with adjustable suspension; a 42-inch deck with 10 height settings from 1.5 to 4.5 inches; and side discharging, mulching, and bagging capabilities.

The electric motor delivers power equivalent to a 22-horsepower (HP) gasoline engine. The Z6 also boasts high-power LED headlights, a battery level indicator, and independently adjustable modes and blade speeds. This mower comes with four 56V 10-Ah lithium batteries, with six available battery slots onboard, and is compatible with any of Ego Power’s other 56V batteries. It also comes with the fastest battery charger in the industry.

With so many features to test, we spent more time with the Z6 than with any of the other battery-powered mowers in this roundup. For our first run, we charged the four 56V 10-Ah batteries that came with the mower and cut as much grass as possible until the batteries ran out. Then we repeated the process with only two batteries, and again with a full “tank” of six batteries.

The mower requires a minimum of 15-Ah to operate, and the charger plugs into the mower to recharge all six batteries at once. Runtime and charge time were as follows: two batteries charged in 1¼ hours and mowed 3/4 acre, four batteries charged in 2 hours and mowed 1¾ acres, and six batteries charged in 3 hours and mowed almost 3 acres (we mowed the entire available area with about 12 percent charge left in the batteries).

We should also mention that the acreage we were mowing included a 1-acre rectangular field and two 1-acre home lots that, in addition to the homes, are approximately 50 percent and 75 percent lawn. The total grass acreage is more like 2¼, with some significant slopes and obstacles to navigate. Since Ego offers an even bigger battery size at 56V and 12-Ah, we estimate that runtime could possibly be stretched to mow up to 4 acres, depending on the condition of the grass and the lay of the land.

The Ego Power Z6’s operation was mostly excellent. Startup was easy, and maneuvering was intuitive. The apparent noise level was extremely quiet and limited to operating the mower deck. The machine travels almost silently when the blades are not running. The lap bars and drive wheels felt somewhat imprecise compared to other zero-turn mowers we’ve used. The machine pulled slightly to the left at full speed on flat ground under an average mowing load. The suspension seat was comfortable, but the relatively small rear tires and light weight of the machine made for a bouncy ride at times. It climbed and maneuvered fairly well on slopes, which is not a strength for most zero-turn mowers.

For most mowing, we kept the machine in “standard” mode and the blades on half power with excellent results. We tested the top blade speed on an area of about 2,000 square feet of overgrown crabgrass that was about 12 inches high, and we had to slow the travel pace significantly to get an acceptable cut in that situation. The Ego Power battery-powered zero-turn mower would make a great choice for any large-acreage owner with lots of grass to maintain.

Product Specs

  • Runtime/recharge time: 30 minutes/120 minutes (4 batteries)
  • Deck size: 42 inches
  • Mobility: Zero-turn riding mower
  • Four 56V 10-Ah batteries included, with room for 2 additional batteries
  • Onboard Rapid battery-charging system
  • 10-position, 42-inch deck allows for ample cutting per pass
  • Mows at speeds up to 7 mph/2.6 acres per hour
  • Bright LED headlights for low-light mowing

Get the Ego Power Z6 riding lawn mower at Amazon, Ace Hardware, or Lowe’s.

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