How To Fix Ryobi 40v Battery Not Charging – 6 Problems and Fixes

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Is your Ryobi 40v battery not charging? I have some good news for you; it is possible to fix most Ryobi 40V battery problems yourself.

Replacement batteries are certainly not cheap, and most of us will want to avoid the need to buy a new battery if at all possible.

Let’s take a look at the most common Ryobi 40V battery problems and how to fix them.

Use the following table to diagnose and jump to the relevant section quickly.

SymptomPossible CauseSolution
Battery not chargingFaulty chargerTest with another battery or charger
Electronics issuePower-cycle your charger by unplugging and waiting a minute
Battery inserted incorrectlyEnsure battery is correctly inserted; press gray button(s) while inserting
Corroded or dirty terminalsClean with sandpaper, rubbing alcohol, or wire brush
Extreme temperaturesEnsure battery temperature is between 32°F to 113°F
Battery is oldIf battery is 3-4 years old or has 300-500 cycles, consider replacement
Charger lights flashing red and greenBattery in “sleep mode”Try micro charges or jump-start with another battery or DC power supply
Reset the battery by accessing internal reset pins

Faulty Ryobi Battery Charger

Ryobi charger not charging

If your Ryobi 40V battery isn’t charging, check if the charger is faulty should be the first thing you do.

But, testing if the charger is faulty isn’t as easy as you might like it to be. This is because we can’t use a multimeter to test the voltage output of the charger.

Ryobi battery chargers have sensors to detect a connected battery. If the charger doesn’t sense a battery, the charger won’t give the correct voltage.

This may cause you to incorrectly identify the battery charger as being the problem.

Power-Cycle Your Charger

Electronics can sometimes act strangely, and Ryobi chargers are no exception.

If your Ryobi 40V battery isn’t charging, first try unplugging the charger, wait for about a minute, then plug it back in.

If this does not solve the problem, move on to the next steps.

How To Check If Your Battery Charger is Faulty

There are two ways that you can check if your battery charger is faulty or not.

You will need a second battery or charger to test the two methods below.

Many people do not have a second battery or charger on hand, so here are some ideas on how to get access to one:

  • Go to your local Ryobi dealer and ask if you can test your battery on their display charger or similar
  • Ask in your local Facebook groups if anyone has a charger or battery you can try.
  • Ask your friends or neighbors if they have a compatible charger or battery pack.

Use Another Battery

Take another healthy 40V Ryobi battery and try charging it. If you have the same problem, the charger is likely faulty.

If the second battery charges fine, your charger is fine, and the battery itself is the problem.

Try Another Charger

You can also use another Ryobi battery charger to check if yours is faulty. This is likely the only way to get a definite answer without a second battery.

Plug your battery into the second charger. If the battery fails to charge or the charger shows an error, then your battery is faulty.

If the battery charges up correctly, then your battery charger is the problem.

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Ryobi Charger Flashing Red and Green – Battery in Sleep Mode

an image showing a ryobi battery in sleep mode

The most common cause for your Ryobi Charger flashing red and green lights is that the battery has been over-discharged.

This is commonly known as the battery is in “sleep mode”

Batteries often enter sleep mode when they’ve been used until completely dead and then stored without charging for a long period of time. The charge on the battery becomes so low that the charger cannot detect whether the battery is healthy or not. 

The charger will stop charging and enter error mode to avoid damage to the charger from a faulty battery.

The problem with most Ryobi 40V chargers is that they don’t incorporate a “boost” feature that would allow a battery that has entered sleep mode to be woken up again.

Here are the best methods for fixing your Ryobi 40v battery that has entered sleep mode.

Micro Charges

how to fix a battery in sleep mode

This method is the easiest, safest and simplest method to try to revive your Ryobi battery that won’t charge.

Patience is required here – so read these instructions carefully and find somewhere comfortable to sit!

  1. Connect your charger to the power outlet
  2. Place the battery in the charger until the green indicator goes solid
  3. Just before the red/green lights start flashing, remove the battery from the charger
  4. Re-insert the battery into the charger again and repeat steps 2-3
  5. Do this until the green light flashes constantly (might take up to 30 minutes)

Why does this work? Each time you put the battery in the charger, the charger gives a small charge before sensing the battery is asleep.

So repeating this process over and over results in the battery slowly being charged in very small increments each time.

Eventually, this results in enough charge for the battery charger to resume normal charging operation.

It may sound crazy, but the graph above shows why it works. Also, take a look at the many pages of comments below this article to see just how often it actually works!

Also Read: Ryobi Pressure Washer Troubleshooting


Jump Starting With a Second Ryobi Battery

using a second battery to jump start a ryobi 40v battery

For this method, you will need: 

The method is as follows:

  1. Connect the positive (+) terminals from the healthy battery to the sleeping battery’s positive (+) terminal. 
  2. Do the same with the negative (-) terminals.
  3. Leave the batteries connected for up to 20 minutes
  4. Disconnect and test the sleeping battery on the charger again

This method may be enough to kick your sleeping battery back into life.

Danger! As with any DIY fix with cordless tool batteries, these methods have some dangers.
Battery university recommends not boosting batteries that have been in sleep mode for a week or longer.

The video below shows in more detail how to do this.


Use a DC Power Supply To Jump Start Your 40V Battery

This method is essentially the same as using a second battery, but instead we use a DC power supply set at the same output voltage (40v)

You will need:

  • A DC power supply capable of outputting 40 volts DC
  • Some wire – standard speaker wire or similar will do the job

The method is as follows:

  1. Connect the positive (+) terminals from DC power supply output to the sleeping battery’s positive (+) terminal. 
  2. Do the same with the negative (-) terminals.
  3. Leave the battery connected to the power supply for up to 20 minutes
  4. Disconnect and test the sleeping battery on the charger again

Reset the Battery

This method means you’ll open the battery to reach the internal reset parts and see the printed circuit board (PCB)

Danger: Lithium batteries can be dangerous when dismantling them. There is a danger of fire or injury – do not attempt this procedure if you are not qualified to do so.

You will need:

  • A torx security screwdriver kit with a T10 size or a Phillips head screwdriver (depending on what screws are used in your battery)
  • A short piece of insulated wire with stripped ends

1. Remove the screws holding on the plastic cover

A diagram showing how to remove screws from a ryobi 40v battery.

Depending on the model of your battery, these screws may be a torx security screw or a standard Phillips head.

There will likely be four screws to remove, and some or all of them may be covered by a plastic plug or cover to access them.


2. Remove the cover

Once the screws are removed, you should be able to love the cover off.

You may need to cut the Ryobi sticker that goes over the seam between the cover and the base of the battery.

This should give you access to the battery PCB. 

At this point you need to be very careful not to short-circuit any connections. Doing so could lead to a fire or electrical shock.


3. Locate The Reset Pins

The Ryobi 40v battery reset pins location depends on the model number.

You are looking for “pads” or pins labeled ‘RST’, ‘RES‘ or ‘RESET

Your model of battery may be listed below, if not it is likely to look very similar – so follow the same instructions,

Model OP40501 and OP40401

Pin location:

Ryobi OP40501 and OP40401 Reset pins

Connect wire between: RST and GND


Model OP40602

Pin location:

Ryobi OP40602 Reset pins

Connect wire between: RESET and GND


Model OP40404

Pin location:

Ryobi OP40401 reset pins

Connect wire between RES and GND


4. Short out the reset pins

Take your wire with stripped ends and very carefully connect the two reset pins. 

Connect the reset pins for 2-3 seconds. You should notice that the lights on the battery pack light up. Now, remove the wire.

Be VERY careful not to short out any other pins or circuitry.


5. Test your battery

You can now reassemble your Ryobi battery (leave the screws out for now) and test if it charges correctly.

If it does, put the screws back in and celebrate!

There is also a good video on this process below.


Battery Inserted Incorrectly

It may seem obvious, but it is essential to ensure your battery is correctly inserted into the charger.

Most Ryobi 40v batteries have a gray button (or buttons) that should be pressed down when inserting the battery into the charger.

Push the gray buttons and slide the battery onto the charger – you should hear an audible click.


Corroded or Dirty Battery Terminals

If the metal contacts on the battery or charger become dirty or corroded, then it can cause the Ryobi charger to assume that the battery is faulty incorrectly.

If your terminals are corroded: then the corrosion can be removed with a piece of sandpaper or some rubbing alcohol and a Q tip.

Dirt on the terminals can be removed with a wire brush or an alcohol-soaked wipe or q tip.

Sometimes, getting to the actual terminals can be difficult because they are recessed. If this is the case you will need to try different tools or items to reach them for cleaning purposes.


Ryobi Battery Charging: Issues with Hot or Cold Temperatures

We like modern Li-Ion batteries, but they have issues old batteries didn’t face.

One of these is the narrower range of temperatures that they will operate and charge in: Li-Ion batteries will generally charge between 32°F to 113°F (0°C to 45°C).

So, the first thing to check if you are having problems with your Ryobi batteries is if they are indeed too hot or too cold.

If it is exceptionally cold where you usually store/charge your batteries, bring them inside and let them warm up to room temperature and then try charging them again.

If it is a hot day, or you have been using your batteries already and they are quite hot, try throwing them in the fridge, or taking them to a cooler area for a short amount of time before trying to charge them again.

Related Article: Ryobi 18v string Trimmer Troubleshooting


Is The Battery Too Old?

Unfortunately, it could simply be that your Ryobi tool’s 40-volt lithium-ion battery is simply getting old. 

Typically, a Ryobi battery or any 40-volt lithium-ion battery maintains its performance for two to three years, or approximately 300 to 500 charge cycles. 

One charge cycle describes the timeline between completely charging the battery, utilizing it until it’s fully discharged, and then charging it up once more.

Once your Ryobi 40-volt battery reaches its third or fourth year, you may begin noticing performance issues. 

This could mean the battery’s inability to retain enough charge or, in more serious cases, it might fail to recharge entirely. Should you encounter this situation, replacing the old battery pack with a new one is recommended.

You can purchase a new battery here.

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What Do The Lights on My Charger Mean?

The lights on your Ryobi charger help you determine the problem with your 40v battery.

The following table is a generic guide as to what the red, green and orange lights mean on your charger:

Battery Pack ConditionRed LED StatusGreen LED StatusOrange LED StatusAction/Description
Power OnONOFFOFFPlugged into AC power supply without battery pack
Testing (Hot battery pack)OFFOFFONWhen the battery pack reaches cooler temperature, the charger begins charge mode.
Testing (Cold battery pack)OFFOFFONThe charger conditions battery until normal voltage is reached, then begins charge mode.
Testing (Deeply discharged)OFFOFFONThe battery pack or charger is defective.
DefectiveFlashingFlashingOFFWhen the battery pack reaches a cooler temperature, the charger begins charge mode.

Where Can I Buy Ryobi Replacement Parts?

If you need your replacement Ryobi 40V battery parts in a hurry, then you will want to head straight down to the closest supplier and buy it locally.

If you aren’t in too much of a rush and want to save some cash, consider purchasing from a reputable online store such as Amazon.

Frequently Asked Questions

Can a Ryobi cordless tool battery be repaired?

Yes, you can repair a Ryobi cordless battery. But, it might take too much time and effort.

Opening up the batteries can be difficult; depending on what part is faulty, it may be quite expensive to fix.

Remember that batteries can be dangerous, so it’s best to get a qualified technician to check the battery for you.

Is it OK to leave a Ryobi Lithium-Ion Battery On The Charger?

No, you should charge the battery after use until it is full, then remove it from the charger and store it in an area that doesn’t get too hot or cold.

The ideal battery storage temperature is around 59℉, but standard room temperature is usually fine.

Do you have any questions relating to this article? Email us at [email protected] or call us on +1 (310) 961-4908

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Author
Aaron is the founder of and Essential Home and Garden. With over 15 years of hands-on experience in home ownership, lawn care, and gardening, Aaron is a seasoned expert in areas like lawn care, DIY, HVAC, and pest control.

284 thoughts on “How To Fix Ryobi 40v Battery Not Charging – 6 Problems and Fixes”

  1. Avatar photo

    Fantastic, I plugged my battery in and unplugged it 3 times and now it is fully charged.

    How did you know this?

    • Aaron Green

      Glad it worked! I’ve just build up my knowledge over the years.

    • Avatar photo

      I did the exact same with identical outcome. Amazing.
      I’d left it in charger for almost 2 days and I only got the flashing red light.
      After trying this fix..hey presto!
      Thank you!

  2. Avatar photo

    Hi,
    Thank you very much for sharing your insight. I have a 40v Ryobi battery than when plugged into the charger the charger light stays green but the battery doesn’t charge. At this time what can I do? Please help me?

    • Aaron Green

      Do you have any other batteries of the same type that do work? You need to work out if it is the charger of the battery that is playing up.

  3. Avatar photo

    Aaron, thank you, Fix Option #3 worked like charm for my Ryobi 40V. Required about 4-5 minutes of in-and-out but then the green stayed solid and battery is charging. Thanks!

    • Aaron Green

      Thats great news! Thanks for letting me know.

      • Avatar photo

        Thought I had a bad battery #3 did the trick – Thank you!!

  4. Avatar photo

    Hey Aaron,
    I have the ryobi mower with 2 batteries. This year I have one battery that won’t work in the mower despite showing its fully charged by the tester. The charger works fine to charge the other battery and the mower works. Any ideas?

    • Aaron Green

      I would say its likely that it is a dead battery.

  5. Avatar photo

    Arron my Ryobi charger shows solid red the battery has no charge and the light stays red when i try to use the weed eater it goes for a second then stops then goes the again any suggestions will be nice
    op

    • Aaron Green

      It sounds like the battery is not being charged – or possibly even that the charger is not detecting that a battery is plugged into it at all.
      This could be a tricky one to diagnose. First thing I would do is clean the terminals on the battery and the charger. The second thing I would do is try to ascertain whether it is the charger or the battery that is faulty. Do you have any other batteries that work in that charger?

  6. Avatar photo

    Aaron
    I have two Ryobi 40 volt Lith to run a chainsaw, 1 battery shows fully charged both on the charger and on the lights on the battery but will not even try to run the saw, the second battery shows defective on the charger ( red & green Lights flashing) with only one light on on the battery but runs the saw just fine.
    Any idea’s

    Roy

    • Aaron Green

      Hey Roy. Sounds like a tricky one. It COULD be a faulty charger? How old are the batteries?

  7. Avatar photo

    I bought a 40v weed eater and charged it last night to full. This morning I used it until it quit and tried it again and it quit again so I put it in the charger and got no lights. I left it in for a couple hours and still nothing. Any suggestions?

    • Aaron Green

      Does the charger have any sign of life at all? Could be a faulty charger if not…. if it does then it is most likely a dead battery.

  8. Avatar photo

    I have a 40 v mower with 2 batteries about 4 yrs. old one battery works fine the other stops with 1/2 charge showing on the indicator can it be fixed or should i replace it ?

    • Aaron Green

      4 years is a pretty good life for any battery – invest in a new one 🙂

  9. Avatar photo

    Just bought tjhe ryobi 40v mower and after charging all night, I used the next mor ing and the charged last 10-15 min. I called support, they said thats not normal and to try fully charging 3-4 times and it “should” last longer. It doesnt make sense to me as to why it would make a.difference but I’ll try. Dpes this sound normal to anyone??

    • Aaron Green

      This is one of those topics that has experts divided. Some people say that you dont need to condition Li-Ion batteries, others say you do. Either way, it can’t hurt to try it as they suggested – worst case you take it back and exchange it for a new one. If you are interested, you can read more technical details about “priming” batteries here: http://batteryuniversity.com/learn/article/how_to_prime_batteries

  10. Avatar photo

    Hi! Does a solid green indicate the battery is charged or a solid red? thanks!

    • Aaron Green

      I believe it would be solid green? But best to double check your manual.

    • Avatar photo

      Yes solid green indicates that the charger believes the battery to be fully charged.

  11. Avatar photo

    Hey this is Sam Peters. I have a battery ryobi trimmer with attachments. I bought a new battery. However when i was outside trimming the yard, the trimmer stopped and then started again. That is even with the battery in and the triggers engaged, it was unresponsive. Then i took the battery out and put it back in and still nothing. Then after a couple of minutes it started working and I was able to get finished. Wondering what it could be?

    • Aaron Green

      It sounds like it could be a heat issue? Maybe the battery is getting too hot, and when you leave it for a few minutes it cools down enough to work again. Does it happen only in hotter weather?

      • Avatar photo

        Not sure to be honest. Haven’t tested that out.

  12. Avatar photo

    I bought a Ryobi line trimmer that has a 40V lithium ion battery and charger. I have it plugged in to (re)charge, the “charging” light is pulsing. I don’t think it’s charging because the “charged” light has not come on and it’s been on for several hours.
    Do I have a faulty battery?, faulty charger? This is new equipment purchased a couple of months ago. Should I take it back to the Home Depot where I got it and get a replacement battery or charger?
    Thanks, Sarah.

    • Aaron Green

      If it doesn’t appear to be charing, then I would take both the charger and battery to Home Depot to get them to check it.

  13. Avatar photo

    Hi! My battery has worked great for about 5 years—this year however, I noticed that neither the charger or battery are lighting up when I attach the battery to the charger. The battery held its full charge from the fall and I used it, but now that it died, it won’t recharge. Does that sound like the battery or the charger? I just ordered a new battery online, I’m hoping it wasn’t the charger

    • Aaron Green

      Hi Sharon, Sorry but it does sound more like a charger issue to me. It seems like the battery has gone completely dead, and because the charger is dead (no lights) the battery won’t work anymore either. Look at the positive side though, you will now have two batteries to use!

  14. Avatar photo

    An issue with this battery…any advice?
    The battery works to start the mower but once you turn the mower off, if you go to restart the mower you have to pull the battery out and reinstall it for it to work?

    • Aaron Green

      The first thing I would check is if the contacts on the mower or the battery are dirty.

      • Avatar photo

        Thank you!

  15. Avatar photo

    Arron,
    Can you tell me what signal the t1 terminal needs to tell the charger to put out the 40 volts? If I connect the ground it goes to defective even though the battery has 39 volts. I’m just trying to get the power supply in the charger to turn on.

    • Aaron Green

      Hi Vincent, Sorry but I am not sure. I havent currently got any of the devices here to check how they work at the moment. Maybe someone else can help out if they read this.

  16. Avatar photo

    Is there a way on the charger to bypass the sleep check function?

    Or if I had another charger from a different manufacturer with the correct voltage does anyone know what the electrical connections are inside the battery that need to be connected to.
    I saw one source online that showed the hook up, but it was for a ryobi 40v but the main board inside was constructed different than the board in mine

  17. Avatar photo

    Yes. I left it unplugged for a few days and it’s still flashing red & green.

    • Aaron Green

      It certainly sounds like your charger may need replacing.

  18. Avatar photo

    I habe a 40v ryobi battery than when plugged into the charger the charger light stays green but the battery doesn’t charge nor work in any tool. Can that be fixed

    • Aaron Green

      Sounds like a faulty battery to me. Whats the model? I can find a replacement for you if you like.

  19. Avatar photo

    I had the same issue as Larry W. Connections are clean. Continued trying the fix even though the lights were just flashing red & green continuously. Now my charger just flashes red & green even without a battery attached. Any advice?

    • Aaron Green

      So if you power off the charger for a while then plug it back in it still flashes red and green?

  20. Avatar photo

    Hi Aaron, I think you are the expert I should ask my question. I got a Ryobi 36v charger BCL3620S. When the charger is empty and first plugged in, it showed flashing red light ( the manual says it should be steady red light). After I put the battery in, it was still flashing red lihgt and not charging.
    Then I tried plugged in the charger with the battery already in it. This time the flashing red light quickly turned into flashing green light for a couple of seconds than came the alternating red and green light. I had tried option 3 but the battery still couldn’t charge.
    Do you think I got a defective charger or a defective battery?

    • Aaron Green

      Hi Josh, How old is it? If it is reasonably new, then it would be best to get both checked under warranty.
      I would think that it is most likely a charger fault….

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