I accidentally left the Ryobi cordless drill battery in the charger for probably about 24-36 hours. When I popped the battery into the drill I noticed a difference in function. Usually upon pressing the trigger the drill would instantly spin very quickly and do so promptly. This time (after leaving it in the charger) it starts out very slow and builds up speed. The fullest speed it hits is not nearly as fast as it usually reaches. Also, while using it, it has popped on 3 separate occasions. I’m wondering if this is a crystal in the battery compressing or something as the pop really did not quite sound electrical (though I could easily be
wrong). Should I run this battery down and recharge…or perhaps try and recharge now?


Most likely a NiCad battery, and, you overcharged it. Try running it down and recharging it. Sometimes this will revive one. If that doesn’t do the trick, you will have to get a new battery pack. HF has a timer you can plug into an outlet, and set it for on and off times, so you can avoid overcharging, even if you are out of the house.

Not necessarily! Many rechargeable batteries can be rebuilt. I just sent in three of my Makita 9.6V batteries and they came back better than new!

I have two Ryobi drills, flash light and the rechargeable saw that all use the same battery. I leave my batteries in the charger until i need one and they are sometimes in there for a week or more. The charger automatically shuts down and keeps the battery being charged on float until it is removed. I have five batteries and two chargers and have operated this way for about three years without any apparent loss of battery life. Now I can’t say as much for some of my friends who have gotten those “good” deals at Sears, and I have several pieces of their hardware in my junk collection.

I have the drill/flash light set and I bet we have the same type of charger. Once the battery is charged the green light is suppose to come on and that indicates the “maintenance mode”. The green light was on when I saw it and unplugged it. This doesn’t seem to be the type of charger that has to be timed. I’d be surprised if that is causing my battery to act sporadic and different, however I can’t think of any other reason. I guess I’ll find out whenever I need to charge it next and report back. I’ll be disappointed if it’s permanently messed up as battery packs are pretty expensive… But especially because I’ve been very satisfied with this drill and thought the battery life was decent. Thank goodness for two battery packs coming in the kit.

Keep your eyes open for their battery special. I got a second pack of two extra batteries for around 40 dollars which I thought was a great buy. Yes I do have the green light and to date have had no problems with just leaving the batteries in the charger. I hate taking them out to just lay around to find that they have gone dead just when I need a spare. The older batteries would loose about 10% per day and it did not take long until you spare was little more than a good rock when needed. I shied away from cordless for years just because of the unreliability of the batteries. I BTW have a mini driver that has the Lithium batteries and it is a champ, sometimes staying in its carrying case for weeks but is ready to perform when needed. Great little driver for those jobs that can be ruined with too much torque.

I thought I’d chime in on this too. I feel the batteries on drills are somewhat unreliable and mysterious too.
I found an article about NiCad batteries awhile back that indicated they are very suseptable to shock. They are easily damaged by dropping them. The internal membranes in them short and their life is shortened dramatically. Nothing can fix this except to replace them. I’ve also read about them getting what is called a false zero voltage. The only thing you can do about that is to fully discharge them them through a very low resistance resistor. Then fully recharge them. If the false zero situation is what the problem is, then this is supposed to fix it.

If you google “rejuvenate battery” there are some YouTube and other things that tell you how to do just that. I’ve done it with 3.6 and 1.2 batteries and saved every one of them, some came back from total zero dead to like new. Someone on eBay sells the same information. Basically, it involves zapping them with a larger voltage quickly, which burns out little internal shorts between the plus and the minus in the bad battery. Only try it if you feel confidant that you understand what you are doing. But – works for me.

I’ve lost a couple of 18V Ryobi batteries because of moisture. One fell into a rain barrel the other was left out exposed to the weather and rain. They appear fine but won’t charge. Watch the charger when you plug it in and if the yellow and red lights both come on there is an internal fault in the battery. If you leave it on long enough the green light will come on but the battery will act as you describe. Interstate battery stores will rebuild batteries but usually it’s only worth it for expensive Dewalt and Milwaulke batteries that cost 40 + dollars.

I have to add my 2 cents to this discussion: leaving your battery in its charger beyond its needed charge time likely caused it to overheat. If you tried to use the tool with hot batteries, that in and of itself may have aced the battery’s demise as you should never use a ni-cad tool battery while still hot. Finally, I would never leave my ni-cad batteries in a charger after their needed charge time as over the life of your tool’s use, the charger will actually run down the expected lifetime of the battery by causing a slow, small drain of the battery’s charge. I time mine and pluck them out of the charger. Also, do not store your battery in the tool when it is not in use. This too can slowly drain the battery.

Perhaps you should consider a Ridgid drill. Ridgid is the only company that offers a lifetime warranty on its tools (if you register your purchase) AND it warranties its batteries too! Otherwise, Ryobi’s batteries are cheap, relatively speaking to Dewalt, Makita, Milwaukee, Ridgid, Bosch, Crapsman etc. Let us know how the repair goes, if you go that route.

I think I have used a battery directly after maintenance mode a couple of times. As Steve suggested I have indeed dropped my drill (twice) however I’m not sure if this (or the other) battery was in it during the drop. There were not any poor signs using the drill directly after maintenance mode or after dropping the drill.
This battery has been causing shaky performance in the drill since the get-go after leaving it in the charger for around 24 hours after charging was complete and on maintenance mode. I unplugged the charger and stored the battery and used it the next day or so and that’s when I noticed that the speed was definitely off.

The drill and batteries are only a few years old. I’ll be using the rest of that battery life this week and will re-charge to see if it somehow corrects itself. I’ll post the results just in case someone else comes along with that same problem. I’ll also remember from now on to keep the batteries out of the drill/light when not in use. Also, I read in the manual that it’s beneficial to charge the battery close to the time you are going to use it (meaning charge it the day before… Don’t have a battery charged and store it for several weeks).