Long term battery storage

[Tseg]

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I recently bought 2nd batteries for my M11-D and Q3 43.   The Q3 43 battery purchase was because I'm taking that camera on an extended trip out of the country soon, and while there is decent battery life with one, I want the second just in case.   The M11-D battery purchase was because I was spooked about Leica proprietary replacement availability long term... I know that may not be an issue for the M11 for many years, but I wanted to be proactive.  My M11-D battery life is currently crazy good, so I don't really see me needing to rotate them.  I just wanted the extra one for when the initial one falls off on performance years out.   What was interesting is both new batteries arrived dead as a doornail.   The Q3 battery had to be plugged in for a number of minutes before it would even register as charging.   I originally thought I would need to rotate batteries, recharging the backups every few months, keeping them in the 80% power range, for longevity.   But now I'm thinking I can just lock away the M11-D extra battery, uncharged, for years and when I power it up for the first time it will be like new.   Is this a correct assumption?

[3D-Kraft.com]

May be, they meanwhile have some BMS electronics in these batteries that are set into a state of "deep sleep" from factory. So they get activated by first time charging and this does not necessarily mean that they have been "dead" (deep discharged would harm them). In this case, they may propably come charged to "storage level" from factory - but who knows...

Storing Lithium batteries charged to 100% over longer periods of time will degrade them. My recommendation would be to charge (or discharge) them to about 50% state of charge. Usually this means that they are one a good storage level on which lithium batteries usually can be stored for a long time. But again it depends on the additional electronics and how much current that draws from the batteries even when they are outside the camera. As long this is not known, I would not store them over longer periods without checking them from time to time. Perhaps the best strategy is, to rotate them at least every three months or so.

[jakontil]

Yup my 2nd battery for the M11 also came in “dead” state or may be like @3D-Kraft.com stated, kind of deep sleep.. 

i too have the same thought about having an extra battery just in case lol.. anyway, i still believe i might need a backup battery when travelling though still undecided whether or not i would use the 2nd battery sooner or just store it away

[Derbyshire Man]

On 3/1/2025 at 9:10 PM, 3D-Kraft.com said:

May be, they meanwhile have some BMS electronics in these batteries that are set into a state of "deep sleep" from factory. So they get activated by first time charging and this does not necessarily mean that they have been "dead" (deep discharged would harm them). In this case, they may propably come charged to "storage level" from factory - but who knows...

Storing Lithium batteries charged to 100% over longer periods of time will degrade them. My recommendation would be to charge (or discharge) them to about 50% state of charge. Usually this means that they are one a good storage level on which lithium batteries usually can be stored for a long time. But again it depends on the additional electronics and how much current that draws from the batteries even when they are outside the camera. As long this is not known, I would not store them over longer periods without checking them from time to time. Perhaps the best strategy is, to rotate them at least every three months or so.

When I had some drone batteries the advice was discharge to about 60% and keep them in a dry sealed bag in the fridge. No idea if that was sensible or scientifically valid.

[fotomas]

Am 1.3.2025 um 20:49 schrieb Tseg:

But now I'm thinking I can just lock away the M11-D extra battery, uncharged, for years and when I power it up for the first time it will be like new.   Is this a correct assumption?

I had the same idea with some Nikon batteries, that I bought together with the camera as spares. When the used batteries become weak years after, I want to switch to the unused ones. They where all dead and wouldn't take any charge. A costly experience.
So you have to charge them from time to time.

[Tseg]

Thanks for that.

[3D-Kraft.com]

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vor 17 Stunden schrieb Derbyshire Man:

When I had some drone batteries the advice was discharge to about 60% and keep them in a dry sealed bag in the fridge. No idea if that was sensible or scientifically valid.

For the LiIon cells, storage at around 3.8V (per cell) in cold temperature slows down the aging process. They can survive many years in this condition.

But as i already wrote: Since many years, the manufacturers usually add some electronics to the batteries to make them "smarter". Sometimes, it is only some kind of passive balancing and may be an undervoltage or short circuit protection. Sometimes it is also some kind of "dongle" in order to make it more difficult for third parties to get some piece of that cake. Most of these electronics draw more or less continuos current from the battery, even when it is stored outside the device for what it was designed. So it is only a question of time, until these batteries die from deep discharge.

So, the advice to charge/recharge them (to storage level) from time to time (e.g. every three months) or to rotate them with the other batteries, is the best you can do.

Edited March 4 by 3D-Kraft.com

[Tseg]

Once again… both the M11 and Q3 new batteries arrived completely dead.  I put in my cameras and cameras did not turn on.  I put the Q3 battery in the charger and it took minutes to even be recognized by the charger, then spent hours to be charged from empty.  I have not yet charged the M11 battery.  I was wondering if someone knew definitely about this new battery dead-state before being charged.   It seems like it would be a method for battery manufacturers to allow newly produced inventory to remain in “new” condition for extended periods of time.   

[lct]

I would charge the battery properly before jumping to conclusions. Can take some time but i don't recall having put a new battery in a camera before charging it personally. YMMV.

[jaapv]

2 hours ago, Tseg said:

Once again… both the M11 and Q3 new batteries arrived completely dead.  I put in my cameras and cameras did not turn on.  I put the Q3 battery in the charger and it took minutes to even be recognized by the charger, then spent hours to be charged from empty.  I have not yet charged the M11 battery.  I was wondering if someone knew definitely about this new battery dead-state before being charged.   It seems like it would be a method for battery manufacturers to allow newly produced inventory to remain in “new” condition for extended periods of time.   

Not that extended. Batteries do self discharge over time. If they have been on the shelf … just pop them on a charger and see what happens. 

[Tseg]

I have now gone the route of charging both new batteries so now both will be in rotation with the original ones that came with the camera and stay mid-charged.    I could find no information suggesting depleted "new" batteries from the manufacturer were intended to be that way.   I was hoping to find this hibernation state from the factory was intentional, but, more likely, the manufacturer let them become depleted on their storage shelf... maybe they were both 99% depleted and not 100% depleted?

[kiwidad]

On 3/1/2025 at 1:49 PM, Tseg said:

I recently bought 2nd batteries for my M11-D and Q3 43.   The Q3 43 battery purchase was because I'm taking that camera on an extended trip out of the country soon, and while there is decent battery life with one, I want the second just in case.   The M11-D battery purchase was because I was spooked about Leica proprietary replacement availability long term... I know that may not be an issue for the M11 for many years, but I wanted to be proactive.  My M11-D battery life is currently crazy good, so I don't really see me needing to rotate them.  I just wanted the extra one for when the initial one falls off on performance years out.   What was interesting is both new batteries arrived dead as a doornail.   The Q3 battery had to be plugged in for a number of minutes before it would even register as charging.   I originally thought I would need to rotate batteries, recharging the backups every few months, keeping them in the 80% power range, for longevity.   But now I'm thinking I can just lock away the M11-D extra battery, uncharged, for years and when I power it up for the first time it will be like new.   Is this a correct assumption?

Incorrect assumption. I find it interesting you bought a brand new battery and it was totally flat.. I can't say I have ever bought a lithium battery that arrived "flat" from my nikon  early DSLR days thru fuji years and now Leica.  Storing batteries fully discharged is not a good plan. I remember the drama days of Metz and the NINH batteries for the big flashes. had to store a very specific way and recharge every so many month or you ended up owning expensive paper weights ( I own several such paperweights). I also can say I never paid attention to charge before using instructions either. I did recently notice an SL2 battery took three charges to decide it wanted to have a proper life though. There are a lot of urban legends and myths surrounding rechargeable batteries thaat came from the old Nicad days and most of those are incorrect!

 

[jgeenen]

I recommend to store the pre-charged cell in a cold environment - similar to a good wine. A (dry) fridge is not a bad idea as long as you bring them back to temperature before use. In a cold environment the chemical processes that deteriorate the battery over time are running much slower and help to preserve battery life.