5 Causes of a Dead John Deere Mower Battery

It’s annoying to have to charge your lawnmower batteries before every use. Time spent waiting for the battery to charge is time that cannot be recovered.

When the terminals on a John Deere lawn mower batteries are corroded, the charging system has failed, the ignition key has been left on, or the battery is defective, the mower will not start.

The battery and electrical system are potentially dangerous, therefore exercise caution when working with them. It’s important to safeguard your skin and eyes with appropriate clothing. The operator of a John Deere should observe all safety measures indicated in the instructions.

John Deere Lawn Mower Battery Keeps Dying

John Deere Mower Battery Connections Are Loose.

If your John Deere’s battery continues dying, examine the connections between the battery and other parts of the machine.

Just run the positive (red) connection from the battery to the solenoid. If you want to go to the starter, you’ll need to keep following the cable down. Verify the integrity of each cable connection.

Connections on a John Deere mower battery show signs of corrosion.

Looking for corrosion at the connections is the next step. A white or green material may have formed on corroded connectors. Your John Deere battery may have a low charge and continually dying if it has corroded.

When corrosion is discovered on a part, it must be taken apart and cleaned.

Unplug the battery cable first.

To break the electrical connection and release the battery, remove the negative cable from the battery.

It’s possible to cause an explosion by removing a battery without first breaking the circuit, which could happen if you strike the frame or another metal object with the wrench.

This means you should always wear protective eyewear and clothing when working with your battery. Once the negative cable (black) is disconnected, the positive cable (red) can be taken out without incident.

In order to keep track of which cable goes where, it’s helpful to know that the positive cable is the one that goes in last and comes out first.

When the battery cables are disconnected, you can remove any other cables that need to be checked, cleaned, or . A baking soda and water solution can be used to cleanse wires and connectors.

Baking soda paste can be made by combining four cups of water with around six tablespoons of baking soda. If you come across any corrosion, apply this paste on it. During the cleaning process, the paste will foam as it works to remove dirt from the cables.

It’s probably best to perform this outside, as rinsing the cords in the solution might get quite muddy inside. Wash off the baking soda paste with water.

One way to hasten the process is to use a wire brush. Cola soda is an alternative that can be used to effectively eliminate corrosion.

Problem with the John Deere Lawn Mower’s Charging System

Checked the charging system after making sure the cables were intact and properly fastened.

Now that you’ve taken care of the cords, you should investigate the charging procedure.

Charger Functionality Check:

  • Check the battery charging mechanism with a volt-ohms meter.
  • Make sure the voltmeter is set to read 12 volts by turning it on and checking its setting.
  • Get your hands on the battery terminals when the car is turned off. Connect the positive (+) connector to the red wire and the negative (-) terminal to the black wire.
  • Knowing the voltage of a battery is an important skill. The voltmeter’s reading ought to be between 12.4 and 12.8. However, depending on the battery’s charge rate and its overall health, some batteries may show a greater reading.
  • Get the reading from the volt-ohm meter and jot it down.
  • Please put on the parking brake and turn on the car.
  • Red should go on the positive (+) terminal and black on the negative (-) terminal when connecting the leads to the battery (-).
  • Start your mower up to three-quarters throttle and have a look at the fuel gauge. A voltage of 13.2 volts to 13.9 volts, or greater, is the desired range for this measurement.
    If this number is greater than the one obtained with the engine turned off, your alternator is successfully charging the battery.

There is a problem with the charging system if the results of the most recent test do not differ from those of the initial test. Ineffective regulation or a malfunctioning stator/alternator could be to blame.

You’ll need to run some extra diagnostics on your lawnmower, or take it in for servicing, to figure out what’s broken. There are also 20 amp systems and 15 amp systems. The dimensions are engine- and manufacturer-specific.

A charging system failure may have multiple causes, and I suggest consulting a skilled mechanic for assistance. Locate a John Deere service center near you to purchase one.

In some cases, a skilled local mechanic may be able to diagnose and fix charging system issues.

It’s possible that one of the numerous pricey engine parts is at problem. Spending a lot of money on replacing random parts in the hopes that the problem would go away is risky and inefficient.

The aforementioned procedure can be performed on your battery at any time using a volt-ohm meter, provided that the cables are clean. It’s possible that a poor connection will be uncovered by running this test.

John Deere Lawn Mower Left with the Ignition Key On

It’s possible that when you were done mowing, you forgot to turn off the engine.

Unless you have an oil warning light on the dashboard or you have a 12-volt accessory put into a John Deere’s accessory connection, the battery won’t be negatively affected.

The next time you attempt to use your mower, you may find the battery is dead since you accidentally left the key on.

To use a battery charger on a John Deere lawn mower, use one of the following strategies. This battery charger from Amazon is great since it features a mode that allows you to charge at a trickle, which is ideal for revitalizing a dead battery.

Typically, the positive (+) terminal is connected to the red wire, while the negative (-) terminal is connected with the black cable.

Method One for Charging the Battery in a John Deere Lawn Mower

  • Cut the power cords attached to the battery. Keep in mind that you should always plug in the positive (Red +) cable last and unplug it first. If the battery’s caps are detachable, you should do so now.You should add distilled water to the battery if the plates within are not already submerged in liquid. Keep in mind that well water is bad for a battery. While using city water is preferable, distilled water is ideal for your batteries.
  • Connect the charger to the battery after you’ve checked the water level.
  • To find out how much juice your battery has, you can use a voltmeter. It shouldn’t take too long to charge the battery if it already has 11.8 volts.A battery of 10.1 volts needs to be charged for some time. If your battery’s voltage is low, charging it will take longer.

    In my opinion, the best “slow bake” is achieved with a very low battery. The charging current of some battery chargers can be adjusted from 6 amps to 4 amps to 2 amps with the flip of a switch.

    A dead battery can be charged in about an hour at 2 or 4 amps. Verify the voltage rate is growing by checking the reading after an hour. If that’s the case, go ahead and add an extra hour to your bill.

Second Method of Charging a John Deere Lawn Mower Battery:

If the battery’s voltage isn’t too low but you still need to use your mower, you can charge it at a rate of up to 6 amps for about 30 minutes to get it back up to about 12 volts.

Take the charger away and turn on the mower once the battery reaches 12 volts. The battery can be charged while the mower is operating if the throttle is set to between three-quarters and full.

When you’re done mowing, take a look at the battery indicator to make sure you’re ready for the next round.

Battery failure on a John Deere lawn mower.

A defective battery can be identified when it has been on the charger for at least two hours and still won’t charge to more than 12 volts. A brand new one is required.

Lawn and garden batteries of the 12-volt variety can be found at any auto parts store, major home improvement retailer, or John Deere dealership.

Simply take out the battery and bring it along. Most places will charge you an extra $15-$25 for the battery core if you don’t bring in your old battery when you buy a new one.

Typically, when you buy a brand-new battery, it will already be at full capacity. But if it has been collecting dust on a shelf for a while, you might need to charge it first.

The battery can be charged (as described above) or jump-started before being installed in your John Deere mower.

How to Jump Start a John Deere Lawn Mower

Use a high-quality battery, such as the one in your car, to jump-start a John Deere tractor. Cozy up the car to the John Deere. Kill the gas to the lawnmower.

The red positive (+) connections on your jumper cables should be connected to the lawnmower’s terminals first, and then to the car battery.

Then, connect the lawnmower’s negative battery post to the black negative (-) cable. Fasten the black cable on the vehicle side to a frame bolt or the alternator bracket.

However, connecting the cable from the vehicle side to the bracket is acceptable because it is not always recommended to go from battery post to battery post.

Put the automobile into gear. To stop the lawnmower, set the brake and then start it. For a few minutes, you should let the mower run. If you disconnect the connections, the mower should start right up.

Again, a volt meter will reveal any problems with the battery’s charging process.

Batteries Typically Last for Three Years or More.

More frequent battery replacement than every three years could indicate a problem with the battery or its connections. When stored correctly, most batteries have a minimum lifespan of three years.

Take care of your batteries by doing as follows:

  • Maintain a clean battery cable.
  • It is imperative that the machine’s battery is firmly fastened and that the cords are snug.
  • Keep the battery from being frozen. Never let your battery die in the cold.

Make sure your battery is properly seated in the battery tray and is not moving around while you mow; vibration is the leading cause of battery failure.

A significant amount of force applied to the battery will crack the plates. Battery life can be drastically shortened by internal plate breakdown.

In addition to heat, cold weather is another culprit in a dead battery. A frozen battery from being undercharged is a bad thing. Before putting away your lawnmower for the winter, make sure the battery is fully charged.

Size of Batteries for a Lawn Mower

If your John Deere lawn mower deck is powered by an electric clutch, you should look into replacing the battery with one that has at least 300 cold cranking amps (cca).

The higher the number of cold cranking amps, the more powerful the battery. A smaller battery, such as 250 cca, will do without an electronic clutch, but larger batteries are preferable.

Check that the dimensions of the battery you select match those of the battery holder.

More about: “Lawn Mower Battery Charging Times Explained“.

Does Your John Deere Mower Still Give You Trouble?

Over the course of owning a John Deere mower, you’re bound to run into a few different issues. Start-up issues, engine failure, vibration, uneven mowing, and inability to move are all possibilities.

I compiled a simple guide for diagnosing issues with your John Deere mower so you can figure out what’s causing the problems you’re experiencing.

More about: “Common John Deere Lawn Mower Issues and Solutions“.