Ryobi Battery Power Source




Introduction: Ryobi Battery Power Source

This is a project I worked on for a friend. He wanted to use several batteries he already had, as a rechargeable power source for his E-Bike upgrade. The bike upgrade kit was available with a proprietary rechargeable Lithium-ion battery, but since he had quite a few rechargeable batteries already, we thought we might try and use them instead. The object was to use 6 Ryobi 18V batteries, without permanently altering the batteries. This would allow for dual purpose use, plug them all together and operate your bike, or remove one and power your cordless Ryobi drill.

Step 1: Create a Removerable Battery Cap

We started off by reverse engineering the Ryobi battery dimensionally. Doing so would allow us to accurately 3D model a removable terminal cap for the top side of the battery. We sourced a couple of spring clips, meant for the negative contact side of a AAA battery from an online electronics distributor. The size and shape of these clips fit the bill perfectly for our battery contacts. After creating the 3d model in Solidworks, we uploaded it to Shapeways.com, and had them print 6 plastic caps.

Step 2: Finish Battery Terminals

After receiving the 3D printed parts, it was just a matter of pushing the contact clips onto each battery cap, and soldering the wires to the terminals. We needed 50V, so we connected 3 batteries in series, 2 times. The three 18V batteries in series provided 54volts, then we wired two of these battery sets together in parallel to increase the amp hours.

Step 3: Button It Up

The batteries fit nicely into a small nylon bag, that gets strapped to the back of the bike. Each battery gets charged individually on a standard Ryobi battery charger, we have three of them. All 6 batteries are recharged in about 4-5 hours. This power supply provides enough power to get the E-Bike up to 30mph, with a range of 20 mileages.

We thought we'd share this project incase anyone else might like to repurpose their Ryobi batteries. The Plastic terminal cap is available to anyone who would like one, on Shapeways, search for Ryobi battery cap. The spring clips were ordered online, Keystone part # BK-204.



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    21 Discussions

    MAJOR UPDATE!!! I've been using these caps reluctantly for a few years now, the only replacement for these I found was by digging the connector out of the old blue Ryobi flashlights but could never find that part.... UNTIL NOW!!! I just bought a dozen, at 1$ each it's a WAY easier way to get the power out of the Ryobi packs! Check it out: https://www.ereplacementparts.com/contact-plate-holder-p-154719.html

    1 reply

    I only say reluctantly because these 3D caps are 8$ each from shapeways, and they are prone to melting if you are pushing the limits on the batteries (i.e. power wheels). The Standard 12V Power Wheels run excellent at 18V, however as the kids got heavier over the years I'm now running them on two 18V packs wired in parallel, much cooler.

    Of course it's the author's choice whether to share his STL file or not -- I agree it would be more in the spirit of instructables to share it, but the good news is you don't need it -- there are plenty of designs on thingiverse.com that will do the job quite nicely. Just go to https://www.thingiverse.com/search?q=ryobi+18v Some even have a complete latching socket so the battery locks in place, just like in a one+ tool. Here's an example: https://www.thingiverse.com/thing:2027076

    Great Job. You answered a lot of questions I had. And IMHO if you don't want to share your STL that's YOUR BUSINESS! You engineered and designed a really beautiful part. Come on guys! This is his design. You can invest your time and make your own, or invest your money and buy his. But please quit investing in telling him what to do! Awesome Instructable.

    I think it is time for you to provide the STL or model files. As of now, this looks more of an ad for your sale on shapeways than a real instructable. Sorry, but this is how it looks.

    I'm looking to do something similar. Would it be possible to provide the files or links neccessary to get the same 3D printed peices?

    1 reply


    Hello there. Can you tell me what type of battery clips you got? Thanks.

    4 replies

    The actual file would be really far more use. Without that, this isn't actually instructional.


    Hello! any chance you'd provide the files for the collar? This would be perfect for running the remote camera base station I'm building!

    Thanks for sharing this! I've been wondering if there's a way to string together multiple Riyobi batteries as a backup power source during a storm! Seems like a great marketing opportunity for them... like a charging brick that can hold multiple batteries with a built in inverter to be able to power things at 120V for a period of time in a storm. Have you tried anything like that?

    We are working on building a quad that will run on 6 of the exact same batteries that you used. What were some cons of using it I'd there were any and what are you running with it.

    2 replies

    Hi NinjaBoy12,

    Don't have any con's to speak of, everything works great. The batteries power a 48v1000w brushless Dc motor, the E - bike upgrade kit was purchased without batteries to save a bunch of money. We love the multi-purpose ability of the Ryobi batteries. The same printed cap will work with the lithium ion version of the Ryobi rechargeable batteries.

    Good luck with your project!

    Very creative, but those batteries are not cheap. You can do the same thing in a smaller case using these batteries. http://www.hobbyking.com/hobbyking/store/__9964__ZIPPY_Flightmax_5000mAh_5S1P_40C.html Plus these are 40C discharge batteries. Or even smaller package would be this http://www.hobbyking.com/hobbyking/store/__19149__Turnigy_nano_tech_4400mah_7S_65_130C_Lipo_Pack.html. A little more expensive but 4 would more than do what you have here.

    2 replies

    Thank you everyone for the kind words. First time poster, long time lurker.
    You're right, these batteries are not cheap. But if you already own them for work or hobbies, it seemed like a great opportunity to repurpose something for which it was never intended. All without the great expense of buying additional batteries and chargers. We're assuming there won't be a lot of people looking for battery options for electric bike upgrades, but hope someone may discover there's endless possibilities for rechargeable batteries they already own.
    Thanks Again,

    Well, but the ryobi batteries can be used (easily) with ryobi tools, plus they already had them.