Lithium ion batteries are a wondrous invention that are lightweight and long lasting. But it's infuriating when the battery won't recharge. You stick the battery in the charger and ... nothing. Guess what? You can fix these batteries that appear to be completely dead. Read on ...
This post is NOT sponsored by Ryobi. They do not approve of or endorse this method for fixing a Ryobi battery. AT all.
Jump straight to the tutorial and how to video.
One of two things are going to happen as you read this post. You will either unfollow me due to my pathological boringness or ... you will propose marriage. So get ready to act accordingly.
If you have any sort of cordless power tool, but especially one powered by a Ryobi 18V battery, you have no doubt encountered the dreaded flashing red charger light.
And if you haven't ... you will.
It inevitably goes like this - you run to the basement to grab your cordless drill because after 10 years of thinking about it, you're finally going to build that 4 level, Tudor style treehouse with kitchenette.
Or you're going to hang a picture. (I can teach you how to hang a picture too)
Either way you put your battery in the charger and all you get is a flashing red light, which according to the label on the charger means your battery is defective. It isn't just dead. It's "defective".
I'm here to tell you it isn't. You probably left it in the charger too long which drains the battery.
Your battery is fine. It just needs a little boost.
This is where you want to go if you're looking for how to boost a car battery.
Table of Contents
You Can Fix a Rechargeable Battery That Won't Take a Charge.
You heard me right. You do NOT have to buy a new $50 battery. You do not have to call the company and swear at them because this stupid "defective" battery is only 2 weeks old. (although by all means feel free to do so) You do not have to wait until they ship you a replacement battery to finish your project. You can get that battery up and working in about 5 minutes.
NOTE: First try pulse charging.
Pulse charge your battery by plugging and unplugging your charger (with the battery in it) for 10 seconds. Try this a few times. If it doesn't correct the problem, continue on with this tutorial.
How to Fix an 18V Battery
What You Need
- A lithium ion battery that won't charge
- An AC adapter (an old phone charger for example)
- A multimeter. (this is actually optional but helpful ... if you don't have one don't worry, you can still fix your battery)
Note: If you aren't used to doing this sort of thing, or using things like a "multimeter" this is going to seem crazy hard and way out of your DIY league. It isn't.
Steps
Step 1. Cut the end off of your AC adapter. That's right. Just cut it off. It's for a 10 year old cell phone, you're never going to use it again anyway. It's frankly kind of weird that you saved it to begin with.
Step 2. Separate and strip off 1" of each wire. You have *just* made booster cables! Good for you.
TIP:
Black wire = negative Striped or solid white wire = positive
IT IS VERY IMPORTANT TO NOT MIX THE TWO UP.
Step 3. Remove the screws holding the battery together.
For Ryobi batteries it's a star shaped screw head like the one below.
A few years ago I bought a kit of small screwdriver heads from Amazon that has every small, weird, head you'd ever need.
TIP:
There's a hidden screw under a piece of plastic. You need to pry the plastic off to get at the screw underneath. I used a very thin screwdriver to pry it off.
Step 4. Pull the top off of the battery case.
Step 5. Remove the 2 plastic side pieces. They're the things you press in to remove your battery from your drill.
Step 6. Lift the battery pack out.
Step 7. Set the Multimeter to read volts. For testing an 18 volt battery choose the 20 volts setting. This will give you the most accurate reading. (If you don't have a multimeter skip to Step 9 and hope for the best)
TIP
Volts are symbolized by a "V" with one or two straight lines over it on a multimeter so it's that section of the multimeter that you use. The section under the V with the straight line(s). Not the squiggly line. The straight line.
Step 8. Touching the red probe to the positive (red) terminal and the black probe to the negative (black) terminal, read the voltage shown on the multimeter. In my case the battery was carrying a charge of 0.06 volts. Which is *almost* nothing, but not completely nothing.
Step 9. Plug your AC adapter in and using the wires, boost your dead battery. Just touch the black wire to the negative terminal (the one with the black wire going to it) and the white wire (or striped wire) to the positive terminal (the one with the red wire going to it). Do this on and off for approximately a minute.
TIP
Apparently lithium ion batteries should be "pulse" charged. Which means you hold your wires down for 15 seconds or so, then release them. Then hold them down again. Over and over.
DOUBLE CHECK THAT YOU ARE TOUCHING POSITIVE TO POSITIVE AND NEGATIVE TO NEGATIVE.
Step 10. Test your the voltage on your battery pack again. It should be higher than it was before boosting. (Again, if you don't have a multimeter don't worry about this - you'll just have to press on without one)
Mine went from 0.06 volts to 7.58 volts after a minute long boosting session.
Step 11. Put the plastic cover back on the battery pack (just the part that goes into the charger) and set your battery on the charger to see if it will take a charge.
If you still only get a red flashing light and the battery won't charge, boost the battery some more. I find the battery charger will recognize that the battery is good again when you boost it to between 10 and 14 volts.
Just keep repeating the "pulse" boosting and testing the battery until it will finally be recognized by the charger and you get the green light.
To those of you who found this subject matter to be on par with spending 3 hours in a waiting room, sorry 'bout that.
For the rest of you? I know exactly how you feel. I felt the same way. Let me know exactly how elated you were after you brought your first battery back to life in the comments section.
Here's a 3 minute tutorial video showing me as I fix my own battery.
How to Fix a Ryobi 18v Rechargeable Battery
Instructions
- Cut the end off of your AC adapter. That's right. Just cut it off. It's for a 10 year old cell phone, you're never going to use it again anyway. It's frankly kind of weird that you saved it to begin with.
- Separate and strip off 1" of each wire. You have *just* made booster cables! Good for you.
- Remove the screws holding the battery together. There's a hidden screw under a piece of plastic. You need to pry the plastic off to get at the screw underneath. I used a very thin screwdriver to pry it off.
- Pull the top off of the battery case.
- Remove the 2 plastic side pieces. They're the things you press in to remove your battery from your drill.
- Lift the battery pack out.
- Set the Multimeter to read volts. For testing an 18 volt battery choose the 20 volts setting. This will give you the most accurate reading. (If you don't have a multimeter skip to Step 9 and hope for the best)
- Touching the red probe to the positive (red) terminal and the black probe to the negative (black) terminal, read the voltage shown on the multimeter. In my case the battery was carrying a charge of 0.06 volts. Which is *almost* nothing, but not completely nothing.
- Plug your AC adapter in and using the wires, boost your dead battery. Just touch the black wire to the negative terminal (the one with the black wire going to it) and the white wire (or striped wire) to the positive terminal (the one with the red wire going to it). Do this on and off for approximately a minute. DOUBLE CHECK THAT YOU ARE TOUCHING POSITIVE TO POSITIVE AND NEGATIVE TO NEGATIVE.
- Test your the voltage on your battery pack again. It should be higher than it was before boosting. IF IT IS NOT, THEN STOP. YOUR CELL COULD BE DAMAGED AND CONTINUING COULD BE DANGEROUS.
- Put the plastic cover back on the battery pack (just the part that goes into the charger) and set your battery on the charger to see if it will take a charge. If you still only get a red flashing light and the battery won't charge, boost the battery some more. I find the battery charger will recognize that the battery is good again when you boost it to between 10 and 14 volts.
- Repeat the "pulse" boosting and testing the battery until it will finally be recognized by the charger and you get the green light.
- Reassemble your battery. Your rechargeable battery is now fixed.
Video
Notes
- Black wire = negative Striped or solid white wire = positive It is very important to not mix the two up.
- There's a hidden screw under a piece of plastic. You need to pry the plastic off to get at the screw underneath. I used a very thin screwdriver to pry it off.
- Volts are symbolized by a "V" with one or two straight lines over it on a multimeter so it's that section of the multimeter that you use. The section under the V with the straight line(s). Not the squiggly line. The straight line.
- Lithium ion batteries need to be "pulse" charged. Which means you hold your wires down for 15 seconds or so, then release them. Then hold them down again. Over and over.
Please direct marriage proposals to my publicist. A certain tool company is *not* interested in proposing marriage to me. So I'd like to make a point of saying I love these tools and use them all the time. Their batteries and chargers on the other hand, could use some improvement.
OTHER WAYS TO FIX THINGS.
- How to Unclog Your Central Vacuum
- How to Sharpen a Push Mower
- How to Replace Carbon Brushes on Any Motor
- How to Mend a Broken Fingernail (because you're surely going to need it after replacing carbon brushes)
Questions & Answers
- Is there an easier way to do this? Possibly. Some people have had success with putting the battery in the charger and waiting for the red light to come on. Then you pulse charge the battery by quickly plugging and unplugging the charger.
- What voltage does the charger need to be? A 12 volt charger will do the trick.
- Isn't this dangerous? There is a small chance of BIG danger. So proceed with caution. If a cell doesn't immediately charge a little bit with this technique, stop. If anything (charger, cells, wires) starts to heat up, STOP.
- How long will the battery last after fixing them this way? Until you accidentally leave it in the charger too long again, or until the battery's natural death.
Seeing as you're the sort of person to make it all the way down here to the end of this post, you might like to learn how to install a battery operated electric fence around a home vegetable garden.
*Proceed with caution and follow instructions exactly. Failing to do so could lead to injury.*
michael barnes
There is another potential issue involved. when you open that battery there are actually several batteries inside. each one provides about 1.2 volts, connected in series until they add up to 18 volts. Int that series wiring, if one battery is actually failed, you will never get to 18 volts. Infact it may prevent the charging from going through to the next potentially good batteries. If you had two bad battery packs you could salvage a good cell out of another one and replace it. You might realize by now that some people have too much time on their hands. Batteries have gotten pretty cheap and come with a warranty. If you have the time to do all of this to save 50 dollars... bless you
Karen
Thanks for the "bless you" and "too much time on my hands" Michael, but the reason I do this is not to save $50 or because I have any more time than any other person does in their 24 our day. It's because (as anyone who does a lot of DIY/handyperson work knows) if you're in the middle of a job and your battery has died you want to get it working immediately. The reason for this of course is because I am a very busy person who works doing this sort of thing for 15 hours a day. I do not have time to run to the store about buy *yet* another battery in the middle of a job. Pulse charging takes a few minutes. And I certainly don't have a week to sit around to complete a project while I wait for a free battery to be shipped by the supplier. ~ karen!
michael barnes
The reason lithium ion batteries will not charge is because of the electronic circuitry. Once you allow a battery to get too low it will not charge. That's the reason lithium batteries are shipped with about a 70 % charge. They can sit on a shelf for years and they will still be partially charged. Once you run a battery to the point of dying, charge it soon because if it discharges any further while sitting on your shelf for six months it won't have enough voltage to recognize it as a good battery.
What they article didn't tell you is almost no batteries are screwed together any longer. They are heat welded and sealed which means you would have to cut them open and glue them or tape them together. Cutting them open gets dangerously close to cutting into a battery cell. Not impossible but not for the faint of heart.
There are actually machines, maybe in a high end camera shop, that will pulse charge these batteries until they wake up. Sounds expensive if you can find one. It delivers pulses, a tiny pulse makes it past the circuitry that shuts it down, eventually you get enough pulses past to wake it up.
Darryl J Birch
... as for the marriage proprosal, my girlfriend might get upset. I'm going to have to settle hitting "follow" on here instead.
Neal
Unfortunately, this method will not work on Makita battery packs. Makita electronics limit the number of times the pack can be recharged and even if the battery voltage is raised, the Makita charger will not continue the charge.
Karen
Well, this fix really isn't for a battery that's been charged so many times that it has now lost power. It's for a faulty board in the battery that doesn't allow it to be charged, even if the battery is brand new. ~ karen!
sachle
Thanks Karen so much!
Karen
You're welcome! ~ karen
leonard
love when a chick knows what she is doing....very confident ...black nails.....get some color
bstacy
Karen, make sure to say to check the wallwart's wires for polarity with the multimeter first; don't assume what the wire's polarity is until you run a voltmeter on it. Many different standards out there.
William Jones
Take me to church Karen.... we're gettin' married!!!!
The circuit board in the battery pack is the "planned obsolescence" to ensure consumers go back to buy more batteries. There is no reason they couldn't program the chargers to do "the pulse" when a low voltage is realized...we have the technology.
Imagine what we will be faced with when more consumers purchase electric cars ... the annual battery scrap rate will be tantamount to a multiple oil tanker spill.... so much for a green energy program.
Keep up the great videos!!!
Marlan Pelham
Why can't this "boost" procedure be performed while still in the outer case?
Karen
Because you're trying to bypass the internal computer card where the actual problem is probably coming from. ~ karen!
Steve Gait
Why didn't you tell me this before I went and spent a small fortune on 2 more cordless drills
Karen
It totally slipped my mind. Sorry! ;) ~ karen
John, 2 way guy
The pulse charge will work unless a battery is worn out. Lithium batteries can only take around 500-750 charge cycles on average. The nickel metal batteries were more. The pulse will work on lithium, nickel metal (NiMh) and NiCad. I have a professional charger that does exactly this procedure. My charger was designed for cell phones. The pulse works better on the older types, but I have used it for years for my own tools. I love the simplicity of your solution, I would do the power "pulse" for 2 minutes and not be discouraged until it took over 10-12 minutes. A word on quality: typically more expensive batteries do use better quality batteries inside. For instance, a $15 battery should not work as well as a $50 battery. For Chinese batteries, well, uh, they are not into quality control like the Japanese or Korean companies. "Nuff said!
Frank woodall
I skipped from the middle step 9 to step 11. Once the battery is in the charger then use your 12 volt DC source to trick the charger into thinking the battery has enough charge to start the charger. Touch + lead to positive end of battery pack and - lead to negative end of pack. A couple of seconds will start the charger. Let charge for a few then reassemble battery and finish charging battery.
Mark
My batt is reading 17.2v but when I place it in the charger all I get is continuous red flashing testing light this is after I have cleaned all terminals and posts
Joseph Cutajar
I use another solution to revive dead rechargable batteries in the case that they are not recognised by the charger due to very low voltage. One could use another battery with a slightly more voltage than that you have, and using the same principle as indicated above - positive to positive and negative to negative and many times it will work. I hope this helped.
Ed
Sounds like a bad idea to me. The pulse charging with an old wall brick is good because chances are, the wall brick is current limited. Charging a dead batt with a good batt may produce an overcurrent situation and damage the batts, cause sparks, and/or cause fire.
Rudolph
Just to let you know: If above is not working after all, you can buy replacement cells very cheap at the wellknown Chinese website's which I will not mention but start with ali and end with baba and so on. You need half an hour spare time and a soldering tool and you have a new batterypack (with probably more capacity then before) for less than 10,-
Joseph Cutajar
That could be another solution, only if the batteries have good amperage. Besides the voltage the amps for the batteries need to be good and correct as indicated on the cells. Sometimes these are not true at all and you will find out later that the charge won't last as long as the original ones.
william williams
I have used the "on/off/on/off" method on several batteries, and for the most part it works. My question is simply why bother taking the battery apart in the first place? There are easy to access + and - terminals without taking it apart. Thanks for the post, btw.
Ben
I would venture a guess that you want to take it apart and pulse the batteries directly because some modern lithium batteries have computer controls built in to the battery. If the battery is almost entirely gone (reading close to zero volts as in the post) the controller won't be able to read detect and relay power to the cells.
But that's just a guess.
Steve Smith
I believe you are correct.
Shadwell Banks
Great technique thanks for sharing!!
Yes - it is possible to do this without removing the casing. I zapped my Bosch drill battery without removing the casing and successfully revived it.
This also worked on my Ikea battery screwdriver.
Mark Spohr
I've done this without taking the battery apart.
David
Girl you are the bomb
Karen
I have it on good authority that Ryobi doesn't think so. ~ karen!
Pablo
Cara Karen,
My name is Pablo and I am very swarthy but I smell okay. I made my battery like you show in the pictures and now is work too well. So thank you for save me one hundred fifty dollars. Your feet make me crazy. Gracias e buenos dias, Senorita.
Jimmy da Creek
Yikes
Indawgwetrust
Karen i hope you and Pablo have a lovely marriage and many beautiful children.
Michael G Crist
¡Prueba "Google Translate" la próxima vez!
¡Tu traductor realmente arruinó tus comentarios!
¡Pero estoy seguro de que "Karen" obtuvo el punto principal, que es su "arreglo" funcionó como se describe!
**********************************************************************************
Try "Google Translate" next time!
Your translator seriously screwed up your comments!!
But I'm sure "Karen" got the main point, which is her "fix" worked as described!!!
Jess
the comments including and after pablo's made my day, had a good, and needed chuckle. thanks all!!
Larry
Karen, I'm new to your feed, but have several batteries I'm gonna try to revive at home using this info. I've been using Makita and Ryobi 9.6v to 18v power tools and batteries for several decades, and this would have saved me much money/frustration over the years. I'll let you know how it goes. In the meantime.... I'm pretty certain my wife of 36+ years wouldn't approve of my serious proposal of marriage to you, and your husband might not, as well, but just rest content that the sentiment is there. I can only imagine the joy of living with a wife who knows this stuff.......
Karen
It would seem pretty joyful at first Larry, but the first time I tried to make the bed with you still in it, it'd lose its charm. ~ karen!
Jim
Just saw this and tried it...I got a green blinking light!
You rock girl!
Bob Funk
Does not seem to work on a WORX power tool 20v battery...unless I am doing something wrong. Has anyone had experience with this? Also, is it possible to hook these type batteries up to a Battery Tender Trickle Charger and have them be "pulsed" back to being able to charge?
Karen
The last thing you can try is to put the battery in the charger and then plug it in and unplug it (the charger) repeatedly. This is in effect pulse charging. The only time the original technique wouldn't work is if your battery is genuinely dead - a very old battery for example. ~ karen!
Greg
This worked for me too! Simply plug in, wait a few seconds, and unplug. Do this repeatedly. Mine started taking the charge after doing it just 3 times.
Karen
Good to know. I haven't had an issue with mine since fixing them so I haven't been able to test it out. ~ karen!
Chuck
Just an FYI, I tried the insert and remove attempt and ruined the 40 volt expensive ryobi charger, bummer. The charger was only 2 years old and had to buy a new one. That battery never did charge even though I was able to charge it to 3 bars with a new battery, really expensive. Real bummer. Thanks for the info.
Karen
Crud. ~ karen!
Bob Funk
If you can see and positively identify the + and - terminals on the battery, and access them, is there any reason you cannot just pulse charge them through the terminals?
Karen
Hi Bob, if the problem with the charger not recognizing the battery is happening on the level of the board (in between the cells and the stem) then charging from the stem won't fix the problem. And in most cases the problem is in the board. ~ karen!
TomT
So after the pulse fix. Would we have to open the battery to redo this everytime it need to be recharge?
Karen
No, no. The pulse fix kick starts the batter back into action. You just need to do it once. (unless you leave the battery in the charger too long again, lol) ~ karen!
ben dover
I just tried the plug and unplug method and it worked - amazing. Took about a minute. now green and charging. Was about the throw it out.
Cliff MCKAY
thanks I will try this.