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.
| Symptom | Possible Cause | Solution |
|---|---|---|
| Battery not charging | Faulty charger | Test with another battery or charger |
| Electronics issue | Power-cycle your charger by unplugging and waiting a minute | |
| Battery inserted incorrectly | Ensure battery is correctly inserted; press gray button(s) while inserting | |
| Corroded or dirty terminals | Clean with sandpaper, rubbing alcohol, or wire brush | |
| Extreme temperatures | Ensure battery temperature is between 32°F to 113°F | |
| Battery is old | If battery is 3-4 years old or has 300-500 cycles, consider replacement | |
| Charger lights flashing red and green | Battery 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
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
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
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!
- Connect your charger to the power outlet
- Place the battery in the charger until the green indicator goes solid
- Just before the red/green lights start flashing, remove the battery from the charger
- Re-insert the battery into the charger again and repeat steps 2-3
- 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
For this method, you will need:
- A second, healthy, and fully charged Ryobi 40v battery
- Some wire – standard speaker wire or similar will do the job
The method is as follows:
- Connect the positive (+) terminals from the healthy battery to the sleeping battery’s positive (+) terminal.
- Do the same with the negative (-) terminals.
- Leave the batteries connected for up to 20 minutes
- 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:
- Connect the positive (+) terminals from DC power supply output to the sleeping battery’s positive (+) terminal.
- Do the same with the negative (-) terminals.
- Leave the battery connected to the power supply for up to 20 minutes
- 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
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:
Connect wire between: RST and GND
Model OP40602
Pin location:
Connect wire between: RESET and GND
Model OP40404
Pin location:
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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- Model OP4060A
![[2Pack] 40 Volt Battery for RYOBI 40V Power Tools - Generic](https://m.media-amazon.com/images/I/41SHRdnuqXL._SL500_.jpg)
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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 Condition | Red LED Status | Green LED Status | Orange LED Status | Action/Description |
| Power On | ON | OFF | OFF | Plugged into AC power supply without battery pack |
| Testing (Hot battery pack) | OFF | OFF | ON | When the battery pack reaches cooler temperature, the charger begins charge mode. |
| Testing (Cold battery pack) | OFF | OFF | ON | The charger conditions battery until normal voltage is reached, then begins charge mode. |
| Testing (Deeply discharged) | OFF | OFF | ON | The battery pack or charger is defective. |
| Defective | Flashing | Flashing | OFF | When 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.
- Click here to see a selection of Ryobi 40V Batteries and Chargers.
- Also Available at Home Depot
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.
Option 3 worked for me!
Hi! A few weeks ago I purchased a Ryobi 40V HP 21″ Mower (with a 7.5Ah OP40752 Battery and a Rapid OP406 Charger). Once my battery is fully charged, the Charger starts flashing its red and green lights. Since I also purchased a 40V HP Trimmer (with a 4.0Ah OP40404 Battery and another Rapid OP406 Charger) and once my 4.0Ah Battery is fully charged, its charger shows the desired solid green light. I decided to use my two batteries until they were uncharged (both behaved perfectly), and swaped the Rapid Chargers … same result, the 7.5Ah Battery still gets the dreaded red and green flashing lights once fully charged, and the 4.0Ah Battery gets the desired Solid green light on the “swaped” charger. Both my Batteries seem to properly charge (I can see the solid 4 green bars, and the tools work fine for the desired time). Chargers seem ok. Is my 7.5Ah Battery somewhat defective? I love both these powerful devices, but wouldn’t want the 3 yr warranty to expire on my Battery without getting this problem resolved. Thanks for sharing your experience!
YEah it seems like you have a faulty battery – contact Ryobi!
Hey Aaron!
I have a 5ah 40 volt ryobi battery that shows to be fully charged(all 4 lights light up and stay steady) but when I try it on a tool nothing happens. I have also tried re-installing on 3 different chargers and it goes to the dreaded red and green flash. Any suggestions?
Sounds like a dead battery, sorry!
Yes! So glad I found this before I tossed the battery out. Option 3 worked after about 5 quick times. Thanks so much!
I just did the same thing to a 40v Ryobi battery. Aaron said it might take up to 30 minutes. Set an alarm for 10 minutes & got to work. 1st 10 minutes – no results; 2nd set of 10 minutes – started charging just before the alarm went off. Hooray!!!
You were right. It took a lot of patience (a good 15 minutes), but worth the time inserting and removing the 40 volt battery. Finally the green charging light stayed on and battery is charging. Will comment on the end result. Thanks a bunch!
I’ve just encountered the Red/green light flashing for my 36V 5Ah battery and am balking at the fact
that these cost more than the appliance to replace. It has 2 “charge light dot” visible when looking at the charge of the battery, but only one “charge light dot” when in the appliance (lawnmower in this case.)
Voltage measured between +ve and -ve terminals :33.9V
Voltage measured between +ve and T1 :32.6
I’m going to try your recovery method (they’re Li ion, so the procedure should be the same) but I was
wondering if you know if the 36V tools will support a 40V battery.
Will keep you posted if the “wakeup” process worked.
Option 3 worked for me. Battery had 12.5V. A reasonable shown voltage can be a over-discharge battery. I put the battery on and off the charge about 20 times. The green light starting flashing constantly and continued to fully charge. The battery works as expected.
I have a issue with one of my 40 volt Ryobi Batteries. It shows as fully charged but when it’s used in only runs the tools for a few minutes and then quits. If you wait about a minute it will start working again. Still showing full charge. It does this over and over. Any suggestions?
Is the battery getting hot? Sounds very similar to an overheating problem.
I have similar problems with a few 40v batteries I own. They charge fine and if I used the on a low draw system they work fine, but as soon as I put one in my lawn mower or weed whacker they run for a few minutes… stop… then a minute or two later then start up again.
Not an overheating problem as the batteries do not get hot.. seems like a current issue.
Do you have another battery to try in the tool? It might be the tool. My 40v weed whacker does that when using the edger if it gets overtaxed. My guess is that there is something wrong with the tool.
Exactly my problem. It is as if a safety switch in the battery turns off when heavy physical resistance is applied. I have this problem on a 14 inch chain saw. Also, I mounted a 40 volt Ryobe battery on my bicycle. It runs a few seconds and shuts down.
I have had two of my batteries get stuck in my lawn mower over the last two weeks, and I think it’s a common problem that I’ve seen other people in the comments mention.
Upon further inspection what I’ve discovered is that the plastic fins near the terminals of the battery have been warped, as if the battery overheated while in use. They still hold a charge, but they are now incredibly hard to get into and out of any of my tools or chargers.
Try a small file to make those fins smaller. It will take some patience. good luck.
My 40 volt lawnmower is cutting out with a battery level over half. It is warm outside, but is it a possibility I need a new battery
It could indeed be a faulty battery
I had a similar issue. Are you using the bag? The reason I ask is because I discovered the bag, when full, jumped out of the connection slot every time I turned the mower around. Took a while to figure it out but flat I discovered it.
They all flash at the same time four times.
Also the battery is nos accepting any charge.
When you put it on the charger the red and green light flashes on the charger.
I bought a Ryobi OP4026 40v battery, charger, and a couple of weed eaters at a yard sale. I planned on using the motors and battery for some robotics projects. The battery was dead when I got it so I put it on charge. It charged all the way up before giving me the red/green flashing lights. I put the battery in the weed eater and nothing happened. So I hooked one of the motors directly to the battery leads, nothing again. I hooked a multimeter to the battery leads and the voltage slowly drops as the battery slowly drains itself. Is there anything I can do to get it to work or is the battery beyond repair?
Replace the FET on the heatsink. I only get 21 Volts at the output. The main board has 42 volts. Put it apart and charge each bank with 4.1 Volts. Remember polarity of batteries as lithium ion will blow up if reverse charged. Don’t do this if not comfortable with electronic. I take no responsibility for take risks with lithium batteries . Stay safe.
Dear, in France it is called 36V (instead of 40V) but I suppose it is same. Charger using 230VAC for Fast or Slow speed (depend on model). I want to charge my battery using an inverter and small solar panel. Also I need to reduce that charging power (currently 80W – even 300W on fast charger not to modify). 40W should be perfect even if that take more time to fill. I think it is easy to modify inside charger (a resistance value or something else), to reduce output power. Did you already experience this or are you interested in if I find ?
Best regards.
I havent tried this. But would certainly be interested in hearing about your results if you try it.
I purchased the generic battery and the mower will run fine for about 30 seconds and then it shuts off. I release the bar, push the start button and it starts up again. Each time I get 30 seconds before it shuts off. Did this for about 30 minutes while cutting the lawn several times. Battery shows levels of charging as I would expect. Any thoughts?
John
Hi John, it could be a faulty battery? How does the voltage measure on it?
I had same problem with generic batteries in my Ryobi mower, runs for less than a minute and cuts off. If I pull battery out and put back in it runs for less than a minute again and repeat. Replacement generic battery did same thing. Ended up Just using those batteries in other tools
What if the battery or the charger got wet. But neither were plugged in at the time. I tried drying the battery out in the sun but no luck getting it to charge
Unfortunately, electronics and water don’t mix. You probably need charger.
Aaron,
I’d used the refrigerator option a couple of times in the past to get the temperature in range. This time it did not work. In our home, the highest DC supply I could find was 18V. Hence, I tried your Option 3, pushing the battery into the charger for five green flashes, out, five green flashes, out, and so on. It took about seven minutes of this until…voila! I have a working battery and charger again. Thank you, thank you, thank you.
Thanks for the feedback Neil. Glad it worked!
Not only did option 3 work for me on my 40V Ryobi but it also worked on my 18V milwaukee red lithium! I’m so stoked! The Milwaukee had been dead for at least a year and wouldn’t take charge but now its perfectly fine! Thanks for your help!
Fix option 1 does not show underneath the 40 volt batteries the positive and negative wires hook up. Please explain as I see no terminals.
Hi Lynn,
The terminals may be covered on your battery – but I would not recommend that fix unless you have some knowledge in electronics and batteries.
The battery has 4 green lights and no red lights but the blower doesn’t work? Any ideas?
Maybe your blower contacts are not connecting with the battery. It happened to my sister’s weed eater.
My 40v batteries fuel gauge stopped working a week or so ago. Now a week later when the battery is placed in the charger the light stays solid green and never flashes. When I test the battery in the trimmer it works for 2 to 5 seconds and then dies??? My spare battery functions normally in the trimmer and chars fine. Any suggestions?
Hello,
I have a 40 volt 5 ah Ryobi battery. It just stopped working this week when i was trimming my grass with the trimmer. The trimmer is not defective as I tried a spare battery and the trimmer works. When we try charging the
defective battery it charges normally, the green light flashes green until it is fully charged and all the lights on the battery com on when you press the button on the battery. The voltage on the battery only reads 27volts from the + to the – terminal on the battery. When I took the battery apart and measured on the board from the CL1- soldered connection to the Bat+ terminal connection on the board, I measure 41volts. Seems like it is charged but its not getting to the battery out put terminal. Any ideas?
Are the terminals dirty? Could be a dodgy connection between the board and the terminals aswell..
I have a couple of these batteries that are faulty. when I disassembled them all but one had some blue green corrosion on both the top and bottom of several connection points on the board. You may have the same problem. On the top you can get to it to remove but there are several rather large solder connections that you will have to unsolder in order to get remove the board to get to the bottom of it. If you have access to a Pace solder station or something similar you can get the board removed but otherwise…..?