Rebuild Your Ryobi ONE+ Battery Pack





Introduction: Rebuild Your Ryobi ONE+ Battery Pack

About: I'm an environmentally conscious experimenter who loves to bring people together, build things, and when possible...blow things up! See us on YouTube too!

I've had my Ryobi ONE+ system for over five years now and the batteries are shot. Let's see what it takes to rebuild one.

Step 1: Tools Needed

Wire cutter
Soldering iron

Step 2: Take It Apart

Remove six screws from the bottom. Pull the black and orange sections apart.

Step 3: Identify the Cells

Remove the cluster of batteries and identify the number and type of cells are contained in the pack. In this case, there are 15 Nickel Cadmium C cells.
From here we have some options. Since they're C cells, we can replace them with any popular battery chemistry.
We can use NiCad, NiMh or Lithium Ion.
NiCad or Nickel Cadmium are the least expensive and least powerful at $2.70 for each 2400 mAh cell. This gives us a material cost of $40.50 plus tax and shipping.
NiMh or Nickel Metal hydride is next up in cost and power. At $4.85 for each 5000 mAh cell. Replacement of the cells would be $72.75.
Finally, Lithium ion cells are $10.99 each for 3.6 volt 8500 mAh cells. Granted, you would only need 5 to get to the desired 18 volts, but then they're going to rattle around in the case.

Step 4: Make the Purchase!

With the cost of cells alone exceeding the cost of a replacement battery pack, I think it's time to pack this project up and go buy a battery pack.
Seriously, with brand new Ryobi NiCd packs available for as little as $30 and their new Lithium Ion pack for as little as $40, this is not a worthwhile project.
Don't forget to properly dispose of the old batteries.



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    44 Discussions

    Not worth it. The new LIon batteries are $59 for a pair and they last half again as long.

    youi absolutely cannot swap out different types of cells like lithiums, SAYING TO DO SO WILL GET SOMEONE KILLED IN A FIRE OR SPRAYED WITH CAUSTIC CHEMEICALS.

    Ok the berating is done.

    there isd a reason there aren't any NiMH battery packs for tools, NiMH doies well at low discharge rates, but they can't keep up with the demands of power tools.

    I've since switched over to the new Lithium packs. They're way better

    I really appreciate this Instructables! After researching several different scenarios to replace my Ryobi P100 One + battery pack, I decided that it would be cheaper to purchase the same battery pack that I found on Amazon for $22.99 with free shipping with Amazon prime.

    No I'm not a paid advertising for Amazon prime, I just know barking when I see it. I'm not sure this was a true Instructables but it sure did walk me through a procedure where I learned that there were probably about nine dead cells in this one cluster of 15. I double checked with a different meter and still came up with the same number of dead cells.

    By the way, before I took it apart I had reversed polarities and used a 12 V car battery to reset the battery and break up the crystals. This work for about two years but finally it would not accept the charge and I realized that something more was wrong. So I'm grateful for this Instructable and will devote my time to other more worthy DIY projects. Thank you again and hi5.


    1 year ago

    There are several incorrect statements in this article. The cells in the NiCd pack are NOT C cells, they are sub-C cells. And even though the complete 18v packs are fully interchangeable (as long as you use the dual-chemistry charger), the individual cells are NOT interchangeable. Yes, you could replace all 15 NiCd cells with 15 NiMH cells. But you can't rebuild a NiCd pack into a Li-Ion pack. The battery management board of a Li-Ion pack has one (P105 or P108) or two (P104) extra electrical tabs that protrude through the top of the case and interact with the dual-chemistry charger. Without that, you would build an incendiary device instead of a battery pack.


    1 year ago

    No "Rebuild" here - Clickbait & Spam

    1 reply

    How is this "Clickbait & Spam" when there isn't any actual Spam?

    cioty usa

    What a waste of time. Shame on you sir!

    What a trolley car....


    1 year ago

    I respectfully disagree with those who are disappointed in the review. Step one could have said "go to Home Depot or ebay", but at least this shows disassembly, what they look like inside, then the per cell cost of replacement...which is more than the cost of buying brand new, OEM batteries of same or better capacity, without considering your time and effort, which is considerable when trying to solder/weld to batteries. Other, obsolete battery packs may be worth the time and effort to rebuild. However, due to massive availability and thus reasonable cost, there is zero benefit or incentive to rebuild the Ryobi one plus batteries.

    highly misleading. What happened to the Harbor Freight batteries mentioned in the heading. Have rebuilt Black And Decker with them. Was hoping for similar instructions for the Ryobi. You disappoint.

    here an idea but i dont knownhow to do it... would it ve possible to use the adapter to make a corded drill instead? it eould be a neat way to have it ad a back uo option if it was cheap enough?

    You can get 5 x 18650 LiIon batteries for about $1 each on ebay (UltraFire). Of course if you're going to rebuild with LiIon cells, you should put in some charge control circuitry, so that you don't explode it when you try to charge, or drain the batteries too low, but should give you MUCH more capacity. (Technically you can use protected cells, but that will add a bit more.). Charge control circuitry can be had for about $20.

    1 reply

    I would use extreme caution with UltraFire. There are a lot of fakes out there depending on where you buy. One thing I learned as a designer of battery-powered devices is that physics and chemistry limits the capacity of an 18650 to around 3000mA-hr. If you see a battery labeled as higher capacity, then it is almost certainly fake. Take a look at this video to help the warning sink in a bit better:

    The original mah is around 1300. If you replace with nimh with 5000 mah then you are getting a lot more bang for your buck

    1 reply

    You can actually buy those pre-made for $39. Way less than the cost of the cells alone and comes with a warranty.

    This is not good decision-making.You don't have to change all the individual cells, you only have to change the bad ones. You'll need a digital multimeter to test the voltage and if the voltage of some are much lower than specified, they are damaged. If you have a few "used-up" Ryobi packs, open them, test them all, then remove the bad ones. I had 4 not working and after swapping out bad and swapping in good, I was left with 3 good ones that work.

    Keep in mind, also, that if your pack won't charge with the red light, you can sometimes overcome this by simply pulsing the battery while in the battery pack. Red light appears, not green when placing battery in charger. Pulse charger by pulling plug out of socket back and forth rapidly. Often, the pulses will break down the resistance causing the problem and the light will go to green. Once light goes green, let battery charge normally, and when finished, use normally. If red light appears next time, do same. This resistance may sometimes cause the fuse in the battery pack to blow. I've shorted out the fuse to get my battery packs to charge on green, but if you do this, warning: you do this at your own risk of the batteries overheating.

    1 reply

    My time is clearly worth way more than yours. At $12 for a replacement unit, it's not worth doing anything more than dropping this into the e-waste.