Ryobi batteries have a protruding part with battery terminals on it. Here's an example of what the battery looks like.

I'm worried that if the battery is stored in a carrying bag with lots of metallic tools, that several tools could touch each other and the battery terminals to make a short circuit. Thus, I would like to have a cap for the protruding part that covers the battery terminals.

My requirements for the cap are:

  • It must be cheap and fast to make or purchase
  • It must be lightweight
  • It must stay on the battery even if I point the protruding part down
  • Installing and removing the cap should take less than 10 seconds

Ryobi doesn't make such a cap.

I found instructions for 3D-printing a cap but the problem is that I don't have access to a 3D printer.

I also found on eBay a seller that sells such caps, but unfortunately the seller doesn't ship to Finland and the cost of 4 such caps, importing taxes, and shipping would cost so much that I'd much rather make my own.

How can I make a cap for Ryobi battery terminals?

  • 2
    Put the spare batteries in a plastic box - easy, cheap and replaceable.
    – Solar Mike
    Commented Aug 5, 2021 at 16:22
  • 1
    Use a cardboard tube cut to length. If you cannot find one that fits take a larger one and add a slit with a rubber band or tape it with tape to hold its size.
    – Gil
    Commented Aug 5, 2021 at 18:08
  • 5
    Find someone with a 3Dprinter, and give them a beer or two to print it. Most people with 3D-printers tends to be happy to show off ;)
    – vidarlo
    Commented Aug 6, 2021 at 6:18
  • 2
    I'm not sure I'd bother; the chances of what you describe seem so impossibly remote that you're more likely to burn your house down in hundreds of other ways.. If it eases your mind, why not store the battery in the tool or in the charger?
    – Caius Jard
    Commented Aug 6, 2021 at 12:10
  • 1
    Why would anyone carry batteries rattling round in the same bag as metal tools? I use an old briefcase, which holds tools, chargers and batteries - held in some foam.
    – Tim
    Commented Aug 6, 2021 at 16:07

12 Answers 12


In my opinion the easiest solution would be to simply store your batteries, alone, in a smaller bag. You could store this smaller bag within your larger tool bag or carry it separately. Either way, the batteries are isolated from any other metallic objects and protected.

I don't see any advantage to complicating matters by installing stem protectors simply so that the batteries can be more safely jostled about with the rest of your tools.

  • 4
    My spare Ryobi battery travels in the zip-lock bag it shipped in, still good many years later. A quart/liter freezer bag (heavier plastic than normal bags) would fit most batteries. It Works.
    – Ecnerwal
    Commented Aug 5, 2021 at 17:37
  • 1
    That's what I've been doing with my Skill power-packs. One stays on the drill, the other in a zip-lock bag. I originally put the spare one in the charger and stuck that combo in the tool-chest, but I found that when left in the charger there was a slow discharge via the charger going on, leaving the spare battery empty after about 2 weeks. The one on the drill doesn't noticeably discharge over time.
    – Tonny
    Commented Aug 6, 2021 at 10:50
  • 1
    For something much studier than a Ziplock bag, and which will last years, a Tupperware container works perfectly. I use them for my Black & Decker removable batteries. The bottoms and tops 'click' together, making multiple containers easier to stack. An added benefit is that they are also waterproof, (eliminating shorting out by liquid incursion,) but can also contain the battery's contents should it start to leak.
    – IconDaemon
    Commented Aug 7, 2021 at 14:04

Large rubber stopper or buy a pair of baby's socks..

  • Yeah, just use an old sock. Great idea. Commented Aug 6, 2021 at 22:51
  1. Ask around on Facebook/Craigslist/local Ryobi retailer/local recycling yard for a discarded Ryobi screwdriver or a similar compatible tool.
  2. Cut across the handle using a hacksaw,keep the battery holder, discard the rest of the tool. If you happen to cut so that the two halves of the shell come apart,glue them together.
  3. Remove wires coming from the battery contacts or remove contacts as well.
  4. Snap the dummy holder onto your spare battery.
  5. Live happily ever after with a cap that stays on securely and can be applied and removed in just one second.
  • The P700 flashlight/torch seems to be among the cheapest tools on the used markets. Commented Aug 7, 2021 at 19:40
  • @SpencerJoplin I'm not suggesting anyone should buy a working tool and destroy it just to get a battery holder. That feels wrong to me. I would just pick up something on its way to recycling (presumably for free or a nominal fee) and give the battery holder part a second life.
    – TooTea
    Commented Aug 10, 2021 at 7:11

I first explored the opportunity of using a toilet paper shell for this but the problem is that a shell is too large to stay on the terminals and to reduce it inner diameter, I would have to put lots of some soft material like foam inside it, and I didn't have any foam handy.

Then I made the decision to make the caps entirely out of duct tape and paper. The duct tape must be 50mm wide so that its width is significantly larger than the length of the protruding terminal part.

Firstly, cut one long length of duct tape. Align it inverted on the duct tape roll and attach it to the end of the roll in as good alignment as you can. Then cut the duct tape roll again. You will have two opposing duct tape pieces attached to each other:

two duct tape pieces

Then wrap the thing around itself around the protruding terminal part, in as good alignment as you can. You will then have a battery with its protruding terminal part covered by a duct tape shell that's exactly the correct diameter to cover it. Cut any exposed adhesive surfaces (due to misalignment) from the top. Cut a 50mm x 50mm duct tape square and cover the open end above the protruding terminal part with duct tape.

Now you have a shell with one end open and one end closed. Remove the semi-open shell and finish it by cutting any small exposed adhesive surfaces (due to misalignment) from the bottom.

The problem is that the closed end has an exposed adhesive surface inside it. It shouldn't matter much but if you consider it a problem, you can eliminate it in this manner: cut a square of paper slightly larger than the protruding end of the battery terminal part. Fold its sides so that it forms an inverted cup on top of the protruding end of the battery terminal part. It's easiest to do this on top of the battery, using the battery as the model. Then place the inverted cup on top of the protruding end, and slowly slide the duct tape shell around the battery terminal part. IF you do this carefully enough, then you can remove the shell upside down and see that the paper piece is well-aligned but doesn't yet touch the adhesive surface. You can use a small inverted screwdriver so that the handle of the screwdriver is used to gently push the paper to touch the adhesive surface.

(About why you have to fold the sides of the paper: if you don't my experience is that the paper never stays straight when sliding the shell, so that you have a shell with a paper on one of its sides, not where you want the paper.)

Here's the finished product:

finished product from the side

finished product from above it

Note that there are no large exposed adhesive surfaces. The only small exposed adhesive surface is two to three millimeters wide and could easily be cut away with scissors should it be seen as a problem.

I tested that holding the battery upside down, the cap is lightweight enough and friction is large enough to hold the cap on the battery terminals. It's easy to remove in about two to three seconds and reattaching takes about 5-10 seconds.

Four such caps took less than an hour to make even with lots of trial and error. I'm sure that without the trial and error, if I had these instructions already, it would have taken about half an hour for four caps.


Cut a length of big heatshrink, stick it on the stem, heat just the top end of it leaving the bottom end flared/large for easy install. Leave some sticking off the top to makeit easy to pull off

Absent any large enough heat shrink you might be able to acheive the same using a small plastic bottle - the plastic that soda/fizzy drinks comes in shrinks when heated; a small enough one (like a lunch snack size bottle) might shrink to be a good fit for the stem

  • Beat me to it. The PETE bottles that water and soda come in shrink as much as to about half size with a little heat. A sleeve cut from a 16 oz water or soda bottle can be shrunk to a tight enough fit to stay on until you pull it off. Just keep a heat gun on low moving to shrink it evenly. The battery stem shouldn't get so hot as to damage the battery. This is also a good solution for making quick adapters for dissimilar vacuum cleaner attachments and the like, or repairing wooden handles.
    – fixer1234
    Commented Aug 6, 2021 at 17:57
  • Genius point about the vacuum hoses
    – Caius Jard
    Commented Aug 6, 2021 at 18:13

A latex rubber balloon will do the trick. Just stretch the lip and roll it over the stem like a condom. An actual condom would probably work too, as long as it's not lubricated. Latex rubber is a natural insulator, so it should protect your battery from any undesired discharges.

Ryobi battery with balloon protecting the terminals

It takes about a second to put on or take off, and it won't fall off no matter how much you shake or bump the battery. Balloons are inexpensive and readily available most everywhere.

  • you can buy a rubber dog boot at a pet shop that looks like the one in the picture... the opening is larger than a balloon, so it is easier to slip on
    – jsotola
    Commented Aug 7, 2021 at 22:43

enter image description hereI've been using 1 1/2" PVC tailstock that has a flange on it used for drains. Its thinner than normal plumbing PVC and will flex around the battery stem when pushed on. A 2 1/2" piece covers all terminals.


Get some silicone putty and form it around the item, let it set, and pull it off. Put some vaseline or mineral oil on the stem first.

You'll want silicone putty that is on the medium soft side of the shore hardness scale.

Caveat: silicone putty isn't particularly cheap... some people diy it with cornstarch and cheaper caulking silicone in a tube.

enter image description here


3D printing online is relatively cheap, depending on how many components you need. If you can get access to a .step or .stl file (as in your link), then you can print it.

It costs me ~$10USD to start a print $10USD for shipping and then $1-2USD per small part.

For a single part this might be pricey, but if you put it down to a learning cost, then it could be worth it. I use FreeCAD to check the meshes before uploading, but if you have a good file, that may not be needed.

Edit: For clarity, i buy 3D printing, I don't have my own printer


The least-effort answer is to leave the batteries in a tool or a charger when in your tool bag. That doesn't protect additional/spare batteries though.

Another solution is to stretch a large rubber-band so it passes under the battery, over the top of the post, and nestles down in the valley where the side contacts are. The large rubber bands are sometimes used by postal services for holding bundles of letters together.

The "front" contact is a status probe for the charger to read the battery, and does not carry current so does not pose a risk.


You currently have four extras. So buy a 6-port charger (found from your link) and plug them in. When you swap out your first battery, pull out the charger, remove the spare batteries, and plug in the charger and the (discharged) battery. As you swap out future batteries, plug in the discharged battery.

This may be at the high end of what you want to pay, but it would also be the most convenient. No labor, and you now have an easy way to charge your spares. It also allows for six extras later in case you buy another two. And of course if you have additional chargers, you can use those as well.


You probably have access to many thermoplastic containers of various sizes due to grocery and cosmetic shopping. All will soften and some will shrink somewhat if exposed to heat. Cut the bottom off a suitably-sized container, and if it's not a nice push fit over the terminals, use boiling water or a hot air gun to soften/shrink it until it is.

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