Last Updated on October 3, 2021 by Dave Farquhar
I hate when this happens. I’m at the end of a project, I take the battery out of whatever Ryobi tool I was using, put it on the charger, and get that infernal flashing red light. Why are Ryobi batteries so bad? Here’s what to do when your Ryobi battery won’t charge.
Sometimes your Ryobi battery won’t charge just because it’s too hot. Other times it’s because it’s discharged too far, in which case, you may be able to jumpstart it to bring it back to life.
Why your Ryobi battery won’t charge
Going strictly by the book, that flashing red light means your battery is defective and won’t hold a charge. In practice, a defective or dead battery is one of three possible causes for that red light that means your charger doesn’t want to have anything to do with that battery.
Another possible reason is that you drained the battery too low, and the battery doesn’t have enough voltage left in it for the charger to recognize it. A battery in this state can still take a charge, but you have to put enough voltage back in it some other way to get the charger to play nice with it again.
A third possible reason is that the battery is overheated. I’ve seen this happen most frequently with the high capacity batteries after I mow the lawn.
In theory, the battery being too cold could also be a problem, but I don’t think I’ve ever encountered that.
First things first: Let the battery cool down and rest
The best thing you can do at first is nothing at all. Just let the battery cool down and rest. Just set the battery aside, off the charger, and let it sit long enough that it’s cool to the touch. Once the battery reaches room temperature, more often than not, it will charge again.
For that matter, there’s little harm in letting it sit 24 hours. Sometimes after a battery has a bit of rest, it can normalize and recover enough voltage that the charger can recognize it again.
I run into this when we use our 13-inch Ryobi mower and run the battery most of the way down. Let the battery cool off and it charges just fine.
Next, try another charger
If mom says no, ask grandma, right? Some chargers are pickier than others, especially if they aren’t all the same age. The first Ryobi charger I got several years ago has always been the pickiest about what batteries it will charge. I like that charger because it’s big and rugged and has bigger, brighter indicator lights than newer chargers do. That makes it easier for me to tell from across the room when it’s done charging. And that charger can charge both NiCD and NiMH batteries, where newer chargers can only charge NiMH.
But if I push the button on the battery and get no bars, that’s not the ideal charger for the situation. The newer NiMH-only chargers are more forgiving, in my experience.
Try the super-secret “mini charge”
There’s a fairly well known way to try to jumpstart a battery with another battery, but I prefer to try the mini charge first. Place the battery in the charger, then count down how long it takes for the red blinky light to appear. It can be as little as 1-2 seconds. Then take the battery out and put it back in only for the few seconds before the red light starts blinking. You can repeat the process for up to 30 minutes to revive the battery.
One word of warning: My older mixed-chemistry charger, the fussier one, is better for this than my newer chargers are. My newer chargers sometimes decide in less than a second not to charge the battery. The older one gives me a good 5-6 seconds before deciding a battery is bad.
How to jumpstart a Ryobi battery
If the battery won’t take a charge from any of your chargers, you can jumpstart it from another fully charged battery. Make sure you wear safety glasses when doing this, at the very least, because this isn’t the way batteries are meant to be charged.
To do this, you need two lengths of wire long enough to reach between the two batteries, and a way to attach them temporarily to the battery terminals, such as electrical tape. Connect the wires in matching polarity, positive to positive and negative to negative. Let the two batteries sit for about five minutes.
Five minutes should be long enough for the good battery to transfer sufficient charge to the flat battery. Disconnect the wires, then put the flat battery in your charger to see if they get along now. If not, you can probably guess what’s next. Try every Ryobi charger you own. And if none of them want to play, you can try jump starting the battery again for another five minutes, but if the second jump start isn’t successful, the battery is probably too far gone.
Why are Ryobi batteries so bad?
If you’re wondering why Ryobi batteries are so bad, you may be buying the wrong ones. The Ryobi P102 battery is notorious for failing early. I haven’t exactly had great luck with the bigger P104 either.
These tricks sometimes work to bring them back, but eventually these lower capacity Ryobis fail beyond any hope of reviving them. They’re just not a quality product. I’ve had better luck with knockoff Ryobi compatible batteries, or the higher capacity Real McCoy Ryobi batteries. If a Ryobi tool comes with a P102 battery, I’m inclined to buy the tool-only version instead. Even if the price difference is $10, it’s not worth the extra money to me.
The knockoff Ryobi batteries aren’t necessarily great either, but if they come with indicator lights and a button to check the charge, at least you can check them to make sure you’re not draining them all the way. My rule is if a Ryobi or compatible battery doesn’t have lights and a button, I don’t want it. And that’s not just because I see it as an indicator of quality. It might mean better quality, but there’s a practical reason I want the lights and the button.
I buy my knockoff batteries on Ebay. The magic words to search for are “battery for Ryobi P108.” In my experience, they cost less than half what a genuine Ryobi battery costs, and their runtime is more than half as long, and their useful lifespan is a bit longer, so I think they’re a reasonable deal.
I’ve seen my charger give the blinking red light at the end of a charging cycle with knockoff batteries, but as long as I have four bars, the battery works.
Keep in mind that your tools’ batteries are no different from the batteries in your phone or laptop. They all have a finite number of charges in them and will eventually go bad. But the cheapest Ryobi batteries are noticeably worse than their bigger, pricier brothers.
Preventing charging problems
The best way to prevent charging problems with Ryobi batteries is to check the charge from time to time, especially if the tool starts to feel like it’s losing power. While older rechargeable batteries liked being completely discharged, modern batteries don’t. It’s best not to drain them to zero bars if you can avoid it. Running them down to one bar is perfectly fine. But running it on empty until it stops is asking for trouble.
You also want to try to avoid storing the battery without charging it. A low battery tends to lose additional charge over time. If the battery is nearly flat when you store it, it could cross the point of no return just sitting on the shelf waiting for you to charge it again.
I don’t necessarily charge my batteries after every use, but I do try to check them at the end of each project. If I’m down to one bar, I do try to charge it. If I’m half capacity the need is less urgent, but I like to go ahead and charge it. That way I start off my next project with a full charge.
What to do with your dead Ryobi batteries
If you have Ryobi batteries that are dead beyond revival, dispose of them properly. At most home improvement stores, there are two bins near the front entrance. One of those bins is for light bulbs. The other is for batteries. There are hazardous chemicals in batteries, but the chemicals are recyclable. Disposing of them this way keeps hazardous waste out of landfills and contributes to keeping battery prices lower in the future.
If you’re adventurous, it’s possible to rebuild a battery pack. I hesitate to recommend it though. Battery cells can explode when you’re soldering them together. So unless you’re really good at soldering, have very good soldering tools, and know how to get a good solder joint with about one second of dwell time, you’re better off recycling your bad battery packs and buying better (or at least cheaper) packs in the future.