Leica M6 battery drainage note.

[alphonse2501]

Advertisement (gone after registration)

I would like to put my record for M6 battery drains here.

Last week I noticed that my meter readout in my M6 fades, and so I assumed batteries got flat.

Today I take out old SR44 batteries and borrow a multimeter to measure them.

Old battery A: 0.64 volt

Old Battery B: 1.46 volt

This is the measurement for my M6 classic battery drainage over one year. 

 

Also I measure new SR44 batteries before putting into M6, and both of then are 1.75 volt.

[250swb]

Are you putting the speed dial to ‘B’ to switch the meter off? 

[FrozenInTime]

2 hours ago, alphonse2501 said:

Old battery A: 0.64 volt

Old Battery B: 1.46 volt

The batteries operate in series, so individual cell voltages should be equal. Battery A has developed a fault. Replacing the pair is the right thing to do.

https://data.energizer.com/pdfs/357-303zb.pdf

[jgeenen]

The very first generation of M6 had - as far as I remember - a circuit that was prone to drainage (this one did not have the „B/off“ engraving. On my brand new MP I observed „drainage“ as well - I did not put the dial to „off“ before storing the camera into a narrow bad: the padding pressed against the shutter release and kept the meter awake - my fault…

in your case (one battery virtually empty, the one cell lost it‘s charge to the other with every use (basically a cell-to-cell drainage). Probably one cell was older than the other, a different brand or just a little bit different in specs. The 0.46V cell is „dead“ while the 1.46V cell is almost empty. Always exchange both cells (or use - as I do the double size CR-1/3n cell with 3V)

the nominal voltage of a SR44 cell is 1.55V (the higher 1.75V reading is probably caused because you are measuring without load.

 

[Matlock]

Always better to use one DL1/3N battery rather than 2 SR44s.

[Graham (G4FUJ)]

2 hours ago, Matlock said:

Always better to use one DL1/3N battery rather than 2 SR44s.

That's what I have done with all mine, both Leica and non-Leica

[George Collier]

Advertisement (gone after registration)

I have heard from others (and myself included) that the single DL1/3N, at least the Durocell one can die in the brand new package. I bought an M6 a year or two ago, used it with 2 SR44s. When the two died, I opened a DL1/3N unopened (backup) one from when I had bought the camera and it was dead in the package. The problem was confirmed by a friend who has long used M6s and had considerable issues with the DL1/3N but not the SR44s.

[ktmrider2]

You do not mention which version of the M6 (Classic or TTL) you have.  The early versions of the M6TTL were defective and would drain a battery within 30-45 days.  I had one of those cameras and was changing the battery monthly.  I remember sending it to Leica within a few months of purchased and they corrected the problem.  I got the camera back and started changing the battery at intervals of at least a year or more.

[Matlock]

On 10/26/2025 at 10:08 PM, George Collier said:

I have heard from others (and myself included) that the single DL1/3N, at least the Durocell one can die in the brand new package. I bought an M6 a year or two ago, used it with 2 SR44s. When the two died, I opened a DL1/3N unopened (backup) one from when I had bought the camera and it was dead in the package. The problem was confirmed by a friend who has long used M6s and had considerable issues with the DL1/3N but not the SR44s.

I have used DL1/3N batteries exclusively for many years and have never had any problems, perhaps you should check to see if they are genuine Durocell batteries. Lithium batteries should never discharge like that.

[jakontil]

I used 2 SR44s just fine, before was LR44 also oke but easily bloated.. avoid it if possible… DL1/3N is a rarity over here

[catacore]

I have loaded my newly aquired M6 Titanium with a Varta CR-1/3N battery. Bought two, as to have a spare one. They have stamped, on the package, sort of expiry date. Something like 203x (x - I don't remember, but at least 5-6 years from now).