Ways to Fix a Ryobi 18V Battery That Won’t Charge

The Ryobi 18V battery is a powerful option for people who are looking for a cordless power tool. But what happens when your Ryobi battery says fully charged but wont work?

Troubleshooting a Ryobi 18V battery that won’t charge can be tricky but in this blog post, you will learn how to fix these problems so that your tools are always powered up and ready to go!

How To Fix A Ryobi Battery That Won’t Charge

If your Ryobi 18v battery not charging, you may have charger problems that need to be fixed or you may need to make sure your charger is working correctly.

To figure out how your Ryobi 18v battery won’t charge or has lost its ability to hold a charge, you will need to perform some tests with the help of your Ryobi tools and an alternate power supply.

One of the common reasons why a Ryobi 18V battery won’t charge could be because it has gone into what’s known as “sleep mode.” Sleep mode occurs when one or more cells in the batteries are depleted past their critical point which can result in low-performing equipment since there isn’t enough juice running.

The charger is smart enough to know when it’s dealing with a faulty battery and won’t risk charging the device. The red flashing lights mean that you have an issue in this case.

Ryobi 18v battery charger problems: Causes of cell failing in a Battery pack

A battery pack is made up of many cells. When a cell fails, the entire battery pack will fail as well.

When the battery pack is out of balance with cells and unevenness occur, it can lead to cell failure. This happens when the battery is completely depleted and the cells will continue to lose power faster than they’re being recharged.

There are a few reasons why an individual cell might fail, which can cause the Ryobi battery won’t charge. It could be that the cell no longer holds a charge or even accept one. They also may discharge at a different rate (that is noticeable particularly to old battery packs).

Fix even just one cell

Open the battery pack to charge a single cell and check each voltage.

You need to open up a battery pack to charge a single cell. You can now check each cell’s voltage and if it is too low, you can charge the cells with a bench power supply. The goal is for all cells to be within 0.1V of each other when they are charged.

After you charge all the cells put the battery pack back together and try to charge again.

In extreme cases of over-discharge, it’s suggested to use a healthy 18V battery pack to “jump-start” and get its charging circuit back online.

Battery check – is a must!

Ryobi 18V batteries are great because they use a series of smaller cells to power the battery. There’s a chance that if one of them is bad, then the entire battery stack can become useless.

Checking individual cells using a multimeter: While it’s charging (for at least an hour), measure the voltage with a multimeter connected to the terminals of the battery. If it is below your battery rating as shown on the side, you need to replace the batteries.

A lot of batteries have a good voltage but then the voltage goes down when you use them. If your fully charged battery only powers your tools for a short while, you might have a bad battery.

Possibilities of loosed connections

  • You may have been having some trouble with your battery pack not connecting properly to the charger. You could try bending out any bent pins on the connector using pliers so that you get a good connection for charging again.
  • Your battery pack may contain several individual batteries, and you can easily spot a loose connection. The solder connections on the cells that are connected might have come undone, or there could be one of those rare but inevitable defective units.

Carefully plug the battery into its charging unit, making sure to push it in as far and firmly as possible. If you hear a click sound on insertion then your connection is perfect; if not, try again until the red light flashes continuously before moving onto another outlet.

The battery indicator

If you need to charge your battery on the go, you must keep both the charger and the battery pack with a temperature monitoring system. The checking circuits in these devices will stop charging if either becomes too hot or cold. It may prevent charging if the temperature is below 50°F or above 100°F- so be sure to take precautions before taking them out!

How to recover a non-charging battery

One method that has been said to be very successful in recovering a battery is by “shocking” it. This process can save many batteries without you having to dismantle the battery pack.

Place the battery into the charger and quickly plugin. After ten to fifteen seconds, leave it connected for a few minutes while you monitor its charging status red light. If this doesn’t work, try different avenues of troubleshooting such as testing or dismantling options.

Another way of recovering a non-charging battery is to first charge it for 24 hours. This ensures that there is no longer any chemical reaction taking place inside the battery at all and serves to replenish any lost energy. After this time period has elapsed and if no further signs of charging activity emerge, then it is likely that the battery will need replacing.

Ryobi Battery Maintenance: Tips and Tricks

It is important to maintain your Ryobi battery properly for it to last a long time.

One thing that people often forget about is the importance of storing the battery at room temperature, and preferably in an area where it doesn’t get too much direct sunlight or heat.

It also helps if you store it somewhere where there isn’t any moisture present, as this can cause corrosion.

You should also make sure not to charge your battery when it’s fully charged, as doing so may reduce its lifespan.

Also, fixing Ryobi 18v battery is not very difficult. You just need a few tools and some patience.


You can get many benefits from following the tips in this guide. By properly maintaining your battery, you will have a better chance of getting more life out of it and saving money on buying new batteries.

The best rule for remembering how to maintain your Ryobi 18V Battery is to always keep it charged when not in use or store it with at least 50% charge.

Don’t wait until the last minute before charging because that leads to badly performing batteries.

We hope the information above helps you better understand how to fix Ryobi 18v battery by maintaining it correctly and that our advice will inspire you to take care of the rest of your tools.

If we can be of any assistance with anything in regards to these topics, please don’t hesitate to reach out.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.