Is there a common method of preventing batteries from leaking out and destroying the device? Why does this happen in the first place? I have laid another head lamp to waste because it was sitting in my truck unused for several months. Could it be because of the lack of use? In that case, should the batteries be taken out in anticipation of less use?

  • Almost all battery packages say "Store in a cool dry place". While your truck may be cool, it probably is not the cool they are referring to (especially in the summer).
    – Tester101
    Apr 22, 2013 at 12:09
  • Years ago when I was in emergency services, I learned that one brand was far less likely to leak than others. Maybe they use thicker metal in their casings or better sealant, but with the reductions in power requirements of modern technology, the problem of batteries corroding before dying (and ruining much more expensive equipment) is only going to get worse. I've never bought any other brand since. I don't need to advertise by mentioning the name. We all know who they are. (BTW - There's a certain other, very old, brand that I've always found to be the worst about premature leaking. You don' Apr 23, 2013 at 15:47
  • I had two Sony "Cyber-Shot" Ni-MH batteries leak inside a camera and corrode one of the four contacts. A bit of white vinegar on a cue tip cleaned it up nicely.
    – user27221
    Oct 21, 2014 at 18:55

6 Answers 6


Acid cell and Alkaline Batteries function by a process of controlled corrosion of two different elements which creates a voltage potential and a current if the circuit is completed.

This process is in continuous motion from the day of manufacture, while it sits on the shelf in its packaging, while installed in the equipment during off/idle periods. It accelerates with higher discharge rate during use, and continues after the cell is unable to produce useful power to run the device

Alkaline batteries have a sealed container that serves as one of the electrodes. While it undergoes a lot slower corrosion than the case on the old Acid cells, it still corrodes. It is part of the process that allows the battery to function. You don't prevent it.

  1. Dead batteries should never be left in equipment, their process is nearly complete and the shell is close to breach.
  2. Live batteries have a date on them for a reason. Chemical reaction occurs even if the battery is live and able to run the equipment. Often with today's LED technology, for example, the batteries will corrode through and start leaking long before they become too weak to run the flashlight.
  3. Prevention is worth a pound of cure. Remove batteries from the device when not in use for extended periods of time. If it is part of a crash kit where you need batteries with the device at all times for emergency use, store them in a separate ziplock bag and check their dates periodically as well as for leakage.
  4. Don't mix different cells in a device which takes more then one cell. Alkaline cells tend to leak when a potential voltage is applied, i.e. when you try to charge them. This can happen in devices with more than one cell in series if some of the cells have less capacity than others. This is why one should never mix cells by type, brand or age in devices where the cells are connected in series (which is virtually all devices that take cells in the same compartment).
  • I agree completely. And alkaline batteries are obsolete anyway--rechargeable NiMH and Li-ion batteries have comparable or higher energy densities and can be reused hundreds of times. Apr 22, 2013 at 15:17
  • 3
    In emergency services, you learn not to rely on rechargeable batteries. You use Alkaline batteries as a bootstrap to get up and running till you can establish a charging power source. Alkalines are always ready to run, self-discharge means that a good portion of your idle Ni-MH batteries are on partial charge after a week or two. Once you have the charger going pull the Alkalines and run rechargeables for the extended duration. Li-Poly systems are better due to the low self-discharge and much higher power density. You still need a charger power source. Apr 22, 2013 at 15:28
  • "Still useful" and "obsolete" are not mutually exclusive. There are a number of reliable cars from the 70s that are still useful, but that doesn't mean there aren't better options. I think lithium batteries would be a better (but pricier) "always ready" choice because they store more energy, but cost is always important. As battery tech improves, I suspect it will become more efficient in the future to just carry low self-discharge rechargeables and swap them out like alkalines until charging is possible. Apr 22, 2013 at 18:11
  • if you store them in glass, even if they leak, they won't get through the glass Feb 16, 2018 at 23:42
  • @FiascoLabs Actually, even back when you made your comment, low self-discharge NiMH batteries had been around for quite a few years. (Sanyo introduced Eneloop in 2005.) These do have a slightly lower capacity than high self-discharge NiMH batteries of the same size, but it's not a significant difference.
    – cjs
    Dec 10, 2020 at 5:20

Yes on battery removal. I've had better luck with name brand batteries.

Before you pitch the lamp, try some vinegar, scraping off the scale ( I used a cotton swab soaked in vinegar) then neutralize with baking soda and finally rinse with water. I just resurrected a kitchen timer this way.

I think ( but don't know), that the battery chemistry is more likely to leak after a use that fully depletes them, or heats them thru a hard use.

  • 2
    +1 - I too have rescued multiple devices by using the vinegar cleaning technique. My experience is that this works fairly well as long as the battery has not leaked onto a printed circuit board. The chemicals like to eat the copper traces right off the circuit board and it can take some serious rework to get it functioning again -- if ever. I had to toss a computer mouse with this corrosion problem.
    – Michael Karas
    Apr 21, 2013 at 21:15

It is generally always recommended that the batteries be removed from devices that are not in use. Even the device manufacturers recommend this.

I'm not sure what actually leads to batteries leaking other than a failed seal. It is possible that a device exposed to wide temperature excursions may make the battery seals more prone to failure.

There is more information at this link as to what kinds of things can lead to battery seals failing. Like all things on the internet there may be some points made there that are not fully valid ... but the electrical engineer in me tends to agree with these points:

  1. Do not mix batteries of different sizes, brands, remaining charge level and age.

  2. Be aware that a sharp drop or case deformation (denting) of the battery could lead to degradation or failure of the battery seals.

  3. Use common sense and check condition of the batteries in a device fairly often. If a device is to remain idle for an unknown time then play it safe and simply remove the batteries. You can put them in a zipper lock plastic bag so in case they leak you can keep the caustic chemicals contained in a safe place.

  • 1
    Batteries operate by controlled corrosion. Even if sealed, the outer container on Alkaline and Acid batteries corrodes through, releasing the mess into the equipment that contains them. If they aren't in the device, they can't destroy it, as you point out. Apr 21, 2013 at 22:09

The best way to avoid battery leakage is to:

  1. Use newer batteries that are not expired,
  2. Keep them out of hot places, and
  3. Don't mix battery types such as Duracell with Energizer.

Using name brand batteries will also help prevent battery leakage. Make sure to change batteries often.


One option could be to use rechargeable batteries. From what I understand, they're better designed to prevent leaks. NiMH batteries have improved over the years and the newer ones last longer and have a better standby life (such as the Panasonic Eneloop line).


A few more thoughts:

While alkies may leak, the crud they exude is alkiline, not especially damaging to the device and isn't too hard to clear away. Old-style/cheap (zinc-carbon?) Batterues use an acidic electrolyte, which is more destructive if it escapes.

Batteries can go bad before their nominal date I have a package that should have another year on it but that has started leaking.

NiNH is indeed aomewhat less likely to leak, partly because the chemistry is a bit scary (especially when fast-charging)

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