Following the unhappy end of my Nikon D3100, I have upgraded to a new D5200, as a result of which I now have an extra EN-EL14 Li-ion battery and MH-24 battery charger. It would be nice if I could save a little space in my camera bag by storing the extra battery in the slot designed for it in the charger. Is this safe? Will it deplete the battery's charge?

  • 3
    Why not do the experiment yourself? You have all of the necessary gear. Fully charge both of your batteries. Leave one on the charger and one unattached for a few days and then see if the one on the charger is depleted more than the other. To allow for differences in the recharge/discharge performance of the older and newer battery, recharge both, swap them, and do it again. Then write an answer to your own question to let us know your results.
    – Michael C
    Nov 23 '14 at 18:04
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    Have you tried searching for the specific charger's data sheet? I know it's not the same, but I have a AA/AAA battery charger that in the user manual clearly states that IT IS SAFE to store the charged batteries in the unplugged charger, and in my experience, there is no discernible difference in usage or charge retention whether batteries are stored on or off the charger. Of course, I'd apply this warrant only to that specific model.
    – Jahaziel
    Dec 2 '14 at 19:37

I have been storing my spare battery in the unplugged charger for the last 6 months and yes there was depletion of the charge ( 5% per month). I would have to do an experiment to find out if there was less depletion by storing it out of the charger. I never thought about whether it was safe or not until you asked the question. I have not had a problem with said battery being stored in the charger, but if you are worried, I would insert a piece of paper between the battery and the terminals on the charger. Just remember that li-ion batteries should never be completely depleted (never below 20%. For more info go here: http://arstechnica.com/gadgets/2011/02/ask-ars-what-is-the-best-way-to-use-an-li-ion-battery/ Also since you have now 2 li-ion batteries, you should rotate them to get the maximum life out of them. More info go here: http://www.kenrockwell.com/tech/battery-life.htm

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    Ken Rockwell is a source of ... variable quality. His general advice here seems sound, but the percentages and numbers he gives for preserving battery life are highly suspect. Don't take that link too seriously.
    – mattdm
    Dec 2 '14 at 3:51

An unplugged charger may, or may not, discharge the battery if it isn't plugged in to the wall. Depends entirely on the charger's circuitry and may change without notice, even if it's exactly the same model of charger (the model number guarantees it will charge the battery. It doesn't guarantee how it charges the battery)

However, if your battery is symmetrical just put it in the charger the other way round. I put my spare batteries in their chargers like this - takes up no extra space, and nothing is going to discharge itself if the contacts don't line up. The occasional charger has positioning lugs that get in the way, 10 seconds with the wire clippers takes care of that problem.


It should not cause any damage, just the battery will be slightly depleted if left for extended periods of time.

  • 3
    More so than leaving it off of the charger?
    – mattdm
    Nov 21 '14 at 20:31
  • Whether or not the battery will deplete beyond the usual self-discharge depends entirely on the design of the charger.
    – Blrfl
    Nov 22 '14 at 16:04
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    It's a standard Nikon MH-24 charger, if that helps.
    – phenry
    Nov 22 '14 at 17:15

The problem here is that your battery is coming into contact with metal that will conduct electricity. So slight discharge will occur if metal is touching just one end of your battery. If its left on a battery charger its likely that the capacitors on the board of your charger will pull from your battery as well. That being said it should not damage the battery. Only drain them a bit.

  • Define "slight discharge" and "drain them a bit". A piece of metal coming into contact with only a single terminal, and not touching anything else (i.e., not forming an actual circuit), will not show a measurable discharge on the battery. Regarding the capacitors in the charger, the amount of charge they hold is negligible compared to the battery capacity. Assuming the charger's output terminals effectively become an open circuit (very high resistance), there will be extremely little power draw from the battery.
    – scottbb
    May 5 '16 at 18:22

now it depends on charger if batts are charged in parallel then they do as when off they discharge into each other . The one with lowest internal resistance takes current from the others.

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