RYOBI 18V Battery Not Working? [Easy DIY Charging Hack]

A Ryobi battery will typically go bad when it simply has exceeded its number of effective charges, has 1 or more cells that have an internal short, or has simply fallen below the minimum charging threshold for the charger.

In the latter case, the battery isn’t necessarily bad, it just can’t be recognized by the charger because the voltage is too low. However, this case can be reversed with a little hack.

Proceed with the steps outlined in this video at your own risk. This is for entertainment purposes only. Wear safety glasses if you proceed.

Remove the screws on the battery case and the tamper-plug (which will void your warranty, so please exchange your battery if it is still covered).

Check the voltage of each of the cells and see if they are relatively close to each other without any outliers.

If they are, and the overall voltage is just low, you can proceed with modifying the charger to bypass the battery control module that is mounted on the battery.

The steps in this video outline the process.

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Hey when i used to work maintenance we Had a graveyard of ryobi batteries along The back wall when i first started and Since i like to tinker with things i had Free reign to just kind of take these Apart and see if i could salvage them in Any way some of them i could resurrect Some of them were too far gone it just Depended on the reason If the battery sells like One or more were completely burnt out Usually the battery was just junk but if The overall voltage just got below a Certain threshold to where the charger Wouldn’t recognize it like if you left It inside of a tool too long when it was Already dead and the parasitic draw just Kind of drained the battery below that Threshold There is a way to kind of jump start Them and get them back up and running so I couldn’t help it this weekend when i Went to a garage sale and a lady had a Battery there amongst all the tools and She said i could just have it because it Doesn’t even register on the charger and I thought let’s see if i can get it Going i ended up getting it going but Unfortunately i didn’t think about Making a video about it when i was doing It so I’m going to take you back through the Steps in retrospect step by step that’ll Guide you through the process and

Hopefully get you back up and running And get your tool going for your project Let’s get into it So to start this process i have an 18 Volt ryobi battery here and there’s Going to be four exposed screws so go Ahead and take those out you’re going to Need a torx Size 10 Security bit and a nut drive or a Impact driver i’m just using that for The video to speed things up but go Ahead and remove those And then the fifth and final bat uh Screw is going to be protected by a Little plastic tab and this is an Anti-tamper tab to keep you from messing With the inside of the battery and ryobi Puts it there for warranty purposes if You are past your warranty and the Battery is junk anyways go ahead and pop It out with an awl a pick or a reamer And remove that final screw but if you Are under warranty you might as well get A new battery So just keep that in mind before you do Anything stupid From there just gently kind of Rock things back and forth to start to Pry the top from the bottom and once you Do get a little bit of space go ahead And put your finger and thumb where i’m Pointing there and hold the battery down While you pull off the top portion

Because the tower wants to come with it It’s got a good friction fit and you Don’t want to break that tower portion Off which is just plastic go and pull Off the tabs and then you can lift out The battery And it is basically just five cells that Are strung together in series that make Up a total of 18 plus volts 19 When fully charged 19 plus And the battery control module is on top And then the black tape there’s a Thermistor under there that kind of Tells the charger or the battery control Module if the battery is too hot or too Cold to charge it has to be within a Certain temperature range positive and Negative terminals are on top and then There’s a third unlabeled one and i Believe that tells the charger whether Or not the battery is nickel cadmium Lithium and it might even relay Something about the temperature i’m not Sure If we take a reading of the dc volts You can see on the tower that it shows About 18.27 volts And if you actually check the battery Itself it’s going to be 19.54 So the battery actually has more than What registers on the tower which shows That the battery control module kind of Meters the power that goes to the tool

Or to the charger so you’re always going To read a little bit less on the tower Than you actually have Before you continue with trying to jump Start this battery check each of the Cells this is critical You want to see if they are all about Equal If they are you’re good to go to try This trick if you have one or two or More cells that are Way off of the other ones they are bad Then the batteries probably just passed Its point and there’s no point really Trying But if all of the cells are just too low Together you’re going to go ahead and Get three strands of wire i’m using 14 Gauge wire here or 16 rather and i have Some eyelets on One end and bare on the other if you Don’t have eyelets i guess you can just Twist them together like this and that Might work for this purpose And inside of the charger We have three uh charging clips that are On the inside and i’m just gonna hook These eyelets around That pull up just gently not enough to Bend the clips but just enough to keep Tension so that you have good contact And i tape these wires down so that they Can’t Fall back down and lose connection

And basically we’re going to be trying To jump start the battery by bypassing That control board on the top that is Preventing the battery from getting a Charge because the charger just reads That it’s not hooked up to a fully Functional battery and basically we just Need to put a surface charge back on There Notice that the orientation of the Positive and negative are not the same When it comes to the tower versus the Battery itself where you see where you See the letters gnd that’s ground that’s Going to be negative the other side’s Positive So on our charger we have positive on The right so we’re going to orient the Battery now so that the positives on the Right and the negatives on the bottom Left there make sure to wear safety Glasses these two wires are going to go Together and the positive wire is going To go to the top right terminal when we Do this process And we’re just going to do a quick Reading here to see what our voltage is Again just to Demonstrate how this works But we should be about 19.54 19.53 Somewhere in that range With that reading set go ahead and plug In your charger again only do this if All of your cells are about equal and

The overall voltage is just too low you Don’t do this if you have a bad cell You’re not going to accomplish very much Now when i first was at work and i tried This i just tried the negative and the Positive and it doesn’t enter into a Charge mode you see it just blinks Blinks blinks nothing’s really happening Now when you put the um Positive and the on or sorry the Negative and the unlabeled one together And the positive On the battery Then it will enter into a charge mode as You can see with the blinking green Light And this is putting in charge i’m only Holding it here for about Five six seconds for demonstration Purposes And then let’s check the reading again And see where we’re at And already in those five or six seconds I put in about .06 Volts of surface charge on the battery And again i wouldn’t recommend doing This for anything more than about 30 Seconds at a time Just to be careful and you want to just Check and see where you’re at i don’t Know what your voltage needs to be to Get the charger to register it i would Think maybe between 10 and 13 might be Okay but i could be way off on that

Calculation Once you think you have enough go ahead And remove the wires after you unplug The charger And go ahead and put the battery back Together now the surface charge is going To be dropping pretty quickly so you Want to do this about as fast as you can Because again we’re not charging the Batteries when we did that we’re just Putting a surface charge it’s it’s a Crude um Charge on top just enough we’re just Splashing it with electricity and Hopefully it’s enough to where the Charger says yes i’m hooked up to a Battery that can accept a charge so i Will proceed with the charging process Go ahead and plug in your charger Put the battery in to see if it reads And leave the screws out in case you Have to put more surface charge on it But if it reads you’re good to go And uh if not go ahead and take it off And repeat the process until you get That surface charge just high enough to Be uh registered with the charger All right guys i hope this helps you out In getting your batteries back up and Running or at least the ones that could Be resurrected remember do this at your Own risk this is just for entertainment Purposes only and if you have filled out The warranty card for your battery

Remember that you do have three years to Uh redeem that and get a brand new Battery so if you’re already at two and A half years you might as well just get A new one but if you’re at six months The choice is yours you can do what you Want you’re an adult anyways if this Helped you out i appreciate hitting the Like button and take it easy thanks for The view