How to Charge Generac Generator Battery: A Complete Guide With Video

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If you are using an electric Generac generator, either a standby generator or a portable generator, changing the battery is very important. However, most portable generators do come with a manual recoil start mechanism, which sometimes aids the generator when the battery isn’t charged.

The generator battery provides the necessary power to start the generator when the main power source is disrupted. Without a well-charged battery, your generator may fail to start, leaving you without power when you need it most.

According to Generac generator manufacturers, the majority of portable generators fail to recharge their batteries during operation. However, there are exceptions to this rule, notably the Generac GP models 15,000 and 17,500, as well as the all-electric start XP models, which actively charge their batteries while running. In contrast, other Generac electric start generators, except for the mentioned GP models, require an external charger for their battery replenishment.

Apart from these generators charging automatically or manually, there are still times when you will need to charge them yourself. With that, there are different types of ways and methods you can use to charge your Generac generator battery.

This guide will explore the best practices for charging a Generac generator battery effectively. Whether you’re a new generator owner or seeking to improve battery maintenance, this article will provide you with the knowledge you need.

Signs of a Low Generator Battery

Before you start charging your generator battery, you must first identify signs of a low generator battery. These signs can save you from unexpected power failures.

Some of the common indicators of a low generator battery include:

  • Difficulty starting the generator.
  • Slow cranking. 
  • Or a clicking sound when attempting to start.

When you encounter these signs while using the generator battery to start it, make sure you take action and recharge the battery before it’s too late. But for portable generators, you can always use the manual recoil backup pull start to ensure your generator starts whenever you come across this issue.

Also Read:- Generac Generator Not Charging Battery: Troubleshooting Guide

Safety Precautions

When dealing with a generator battery, safety should be your top priority. Here are some essential safety precautions to follow:

  • Never attempt to charge a frozen battery.
  • Avoid smoking or open flames near the battery.
  • Wear appropriate protective gear, such as gloves and safety goggles.
  • Work in a well-ventilated area to prevent the buildup of potentially explosive gases.
  • If you’re unsure about the charging process after reading this article, consult a professional technician.

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How to Charge Your Generator battery, Either a standby or portable generator

Whether you are using a standby generator that automatically charges its battery or a portable generator that needs some steps before charging, there are two primary methods involved, which are:

  • Manual charging 
  • Automatic charging.

Note: Before you begin the battery charging process, ensure your safety and the safety of others. Turn off the generator and disconnect any power source.

Also Read:- How to Manually Start a Generac Generator

The Manual Charging Method

The manual charging of the Generac generator batteries involves using an external battery charger. But how can you achieve that?

Here’s a step-by-step guide:

  1. Locate the battery. The battery is usually housed in a compartment near the generator’s engine.
  1. Disconnect the battery. Carefully remove the battery’s cables, starting with the negative (black) cable followed by the positive (red) cable.
  1. Prepare the charger. Set the charger to the appropriate voltage and amperage for your generator’s battery. Also, if you own another portable generator that has battery charger receptacles, you can connect it to the generator.
  1. Connect the charger to the battery terminals. Attach the positive clamp to the positive battery terminal and the negative clamp to the negative terminal.
  1. Start charging. Turn on the charger and let it charge the battery until it reaches full capacity. Make sure it doesn’t exceed 24 to 48 hours of charging.
  1. Reconnect the battery. And once fully charged, reattach the positive cable, followed by the negative cable, and then start your generator.

However, while this method seems to work for all types of Generac generators, you can also make use of the battery trickle charger cord that comes with the Generac portable generator that isn’t automatically charging.

Plug the charger into a receptacle and connect it to the generator charging spot (if you can’t find yours, check out this trickle charger replacement for portable Generac generators on Amazon). The video by Generac below explains this step in a more detailed way.

The Automatic Charging Method

While some Generac generators require you to manually charge the battery yourself, others come equipped with automatic charging systems. These systems continuously monitor the battery’s voltage and recharge it as needed.

Most portable generators don’t come with this feature, but to find out if your Generac generator did come with an automatic charging system, refer to your generator’s manual to check if it has this feature and how to enable or troubleshoot it.

Additionally, while the feature might seem cool, the other charging method (manual charging) is also needed at most times, especially when the generator battery is extremely low or the battery charging system is faulty and can’t power or even crank the generator.

How to Troubleshoot Generac Generator Battery Issues

Despite regular maintenance and charging, battery issues may arise. Troubleshooting common battery problems can help you identify and resolve the root cause quickly.

Some common issues to troubleshoot include:

  • Corrosion on battery terminals. In this case, to prevent corrosion on your battery terminals, maybe after you keep it for a while, make sure you use battery corrosion preventative.
  • Loose connections. Sometimes the connections on the battery terminals might be loose, maybe because they weren’t tightened up properly at first or probably because of how much the engine had run. In this case, ensure you tighten up the connections appropriately to avoid future connection loss.
  • Damaged battery. This problem cannot be mostly prevented, and when it happens, the best you can do is change the generator battery depending on the type and model you are using. But if you’d use a 22 kw Generac generator, check out our top-picked batteries to buy.

As a generator rule of thumb, regularly inspecting and cleaning your generator battery to avoid such problems at least once a month is enough to keep the batteries in check.

Also Read:- How to Clear Battery Problem on Generac Generator in 3 Easy Ways

How Can You Regularly Maintain Your Generator Battery?

Maintaining your generator battery can significantly increase its lifespan. And at the same time, a lack of maintenance can also decrease its lifespan, causing it to get damaged within a limited time.

But how can you achieve a regular maintenance schedule for your generator battery? Here are a few tips for you:

  • Regularly check the battery’s water levels and top up with distilled water if necessary (for non-sealed batteries). Note: If you haven’t done this before, ensure you meet up with a battery professional to help you with it.
  • Clean the battery terminals to prevent corrosion.
  • Inspect the battery for physical damage and replace it if needed.
  • Last, keep the battery and its surrounding area clean and free from debris.

Frequently Asked Questions

1. How often should I charge my Generac generator battery?

It’s recommended to charge the battery at least every three months, especially during extended periods of inactivity.

2. Can I use a car battery charger to charge my generator battery?

While it’s possible, it’s not advisable, as car battery chargers may not be compatible with generator batteries. It’s best to use an external battery charger specifically designed for generators.

3. Can I overcharge my generator battery?

No, overcharging can damage the battery. Ensure that you don’t charge the battery for more than 24 hours.

4. Can I replace the battery myself?

If you have experience working with electrical systems, you can replace the battery yourself. However, if you’re unsure, it’s safer to seek professional help.

5. How long should a Generac generator battery last?

The lifespan of a generator battery varies depending on usage and maintenance. On average, a well-maintained battery can last around 3 to 5 years.

Final Thought

Not all Generac generators come with an automatic charging system. But as a general rule of thumb, the manual method of charging generator batteries can still be used to charge all kinds of batteries, especially if they are weak or dead and can’t power the generator or even crank it.

As a result of that, following the outlined tips and methods in the article will ensure your battery gets charged adequately. Most importantly, don’t forget to schedule battery maintenance. In short, whenever you’re scheduling maintenance for your generator, also check the battery.

Is there anything I’m missing in this article? Don’t forget to send us an email. If you also have any personalized troubleshooting questions in mind, you can shoot them at us on our forum.

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