I can't seem to find a verdict on this anywhere online. Is it ok to store a lithium ion watch battery (like a CR2032) outside its packaging? Will the battery discharge faster?

I'm not planning on taking them all out and throwing them in a bin. I figured that wouldn't be wise. But I recently got a 3D printer and I'm thinking of making up a storage tray with slots for spare batteries that I occasionally need for various smarthome remotes and sensors around the house.

As long as there is nothing conductive (not even slightly) in contact with/between/across the two faces of each coin battery they will not self-discharge any differently than when inside the retail packaging.

If there is a chance the batteries could sit for years before being used, consider some sort of marking to indicate when they were ‘new’. Battery voltage testing does not tell the whole story, an old but ‘never used’ coin battery will have less remaining charge than one manufactured quite recently.

How much self-discharge occurs varies with the battery chemistry and battery ‘type’. Alkaline vs. Silver vs. Lithium, and so on.

All this is assuming the batteries are kept in a dry location that does not get too warm. Dampness also encourages potential surface corrosion.

I worked in a jewelry store for several years and changed about a billion watch batteries. The battery packaging isn't there to keep them "fresh", so your idea would work in theory.

Things your storage system should do:

- Watch batteries can be problematic because their entire surface area is their contact surface, so it's very easy for them to short out. So you have to design your storage system so that it completely surrounds each cell in all directions.

- Like all batteries, when they get old or they have a defect, they can sometimes leak/corrode. So your storage system should fully seal each cell, so that it contains the mess if leakage ever happens.

- The identification markings on the batteries are frequently hard to read and ID. Two different watch batteries may be very similar in size, shape, and appearance, but still not be interchangeable. There are also multiple identification systems with different numbering schemes. So your storage system should have room to print as much information about the battery as possible, in a way that is larger and more legible than the etching on the battery's surface.

- Your storage system should also be able to show each battery's shelf time and/or expiration date, if possible, so you can tell at a glance if the battery is likely to be a good one.

- Some brands of battery can be better than other brands, so your storage system should allow you to differentiate the batteries by brand.

- Your storage system should have a method for keeping the battery's information coupled to the battery itself, so that if the storage unit is tipped over or shaken, you don't lose the information for each battery.

- Because the storage system needs to fully surround each battery, you would need to make sure that the battery itself is visible from the outside of the storage container, so you can tell whether the container is empty, or if the battery has leaked.

I think the best idea would be to start with a large tray, perhaps a foot or two wide, a foot or two long, and a few inches deep. This could be on some kind of rail system so that it slides out from the side of a larger storage area when you pull upon it. Then, inside this sliding storage tray could be many small individual containers, each housing a single battery or a small group of the same battery, to keep them sealed against leakage and shorting. Each container could cleverly double as the place on which to print all of the complex information about each battery. Ideally, each container would be partially transparent, so that you can see inside to assess the condition of its contents, perhaps the top half of the container could be clear plastic if possible. There will be two long-term difficulties with this system: making sure that you create the right number of storage containers to match the number of batteries that you intend to stock, and the inscribing of the detailed information about each battery onto each storage container.

Thanks for the info, folks!

Tony, I'll keep all of that generally in mind. But for the most part, I'm not going to be too obsessive about this. Many of the batteries, like the CR2032's and the CR2450's, are going into smart home devices that VERY rarely need replacing and alert me well in advance of failure. If the batteries are messed up in storage It's really not the end of the world and I'll just order more. Same for if they lose some life on the shelf. As long as they're not corroded, if a battery can just get me through until a replacement arrives, or can run the device for 1 year instead of 3, I'll be fine.

And the rest of these tiny cells are generally for things I honestly could care less about, like the tiny compartments in various cheap kids' toys. Some of them would go into the speaker compartments for their books...if there were any that I didn't already want to rip the speaker out of...

BTW, I'm still working on a system for these. I've found files for boxes that I can alter to fit the different battery sizes, but I want to put these on a Wall Control "pegboard," and I'll need to figure out how to do that first!

I think my subtlety in my prior post might not have shone through well enough...

couldn’t ?

The sarcasm tag got lost again.

I used to lobotomize my kids' toys that didn't have on/off switches and wouldn't shut the hell up!

My apologies if so I should have made it clearer to start that I'm not super fastidious about how these will be stored. I mostly wanted to get rid of the packaging that takes up so much space relative to the battery.


Dang, that one got through. The "could" folks are getting to me...

Gotcha. I was making a long-winded joke about reinventing the wheel.