Alternative to PX625 battery

[Nitroplait]

I have had one camera, a Leica M6, recalibrated for 1.5V batteries but this is expensive and you still need a physical adapter if you want to use silver or lithium batteries (because alkalines are not a great choice).

You must be thinking of another camera. M6 uses 1.5v from the factory.

 

[chuckroast]

You must be thinking of another camera. M6 uses 1.5v from the factory.

You are correct. I meant an M5.

 

[Donald Qualls]

They last half a year on average and are dirt cheap.

They're getting harder to find, though. Most of them are made for hearing aids, and almost no one is making hearing aids that use those batteries any more.

 

[Nitroplait]

They're getting harder to find, though. Most of them are made for hearing aids, and almost no one is making hearing aids that use those batteries any more.

You are probably right. I have wondered the past 10 years who’s actually using these (aside from me) but for me they are still much easier to find than the SR43s that goes into the active MR-9 adapters. Other than online, I can only find LR43 in watch shops- and they charge crazy money for them.

 

[blee1996]

Hearing aid zinc air batteries are still very easy to find both online and in pharmacy in the US. And their price is super low.

I do recognize the constant discharge and potential leaks. So I always set a calendar reminder to replace them every 6 months or so. Or I don't keep them in the camera unless I'm regularly using it.

 

[halfaman]

They last half a year on average and are dirt cheap.
Can’t imagine the pain you must feel with the battery life of your phone or digital camera

The thing is that they last half a year wether you use the camera or not. On the other hand, a couple of SR44 can last apparently almost forever in my Nikon FM2n as long as I don't turn it on. Ok, I have to admit that my digital camera rechargable batteries discharged after 3 years without any use. But besides that, I can keep the batteries of the cameras I reallly use out without any special care and they keep alright.

 

[Vlad @ausgeknipst]

Hi everyone — first post here. Found this somewhat out of date thrad while searching some info on the Varta V80H battery on the web. Hope its okay to revive it here.

I'm Vladi from Ausgeknipst, a small workshop in Germany where we design accessories for analog cameras. We built the V80H charger that a few members mentioned in this thread. Full disclosure so nobody has to guess.

Saganich asked how you even recharge these. That was the exact question that started this project. Before the charger existed, the only options were a lab bench supply or soldering your own circuit. The original idea of using a V80H as PX625 replacement comes from Troeszter.net — his DIY build instructions (free PDF) are linked in our comparison article. We designed our own USB-C charger with a custom PCB, 3D-printed housing with spring contacts — a different approach to the same core idea.

On the MR-9 vs. V80H discussion: both approaches have trade-offs. The MR-9 with a Schottky diode theoretically delivers ~1.35V from the SR44's 1.55V — but the actual voltage drop varies with temperature and current draw. It's not as stable as it sounds on paper. The V80H delivers 1.30-1.32V fresh and holds steady for weeks. Neither is perfect. Both work.

One thing to be aware of with any below-1.35V solution: CdS photoresistors are non-linear. At low light levels (EV 6), the voltage difference barely matters. At bright sunlight (EV 15), the error from a 1.5V alkaline can reach up to 2 stops of underexposure. The V80H errs in the opposite direction (slight overexposure from lower voltage), which is the safe side for negative film.

On self-discharge: one important detail — the V80H is not a standard NiMH cell. It's a Low Self-Discharge (LSD) NiMH from Varta's industrial "Robust" line, built for server RTC backup and medical devices. The self-discharge profile is comparable to the Eneloop series. The discharge curve also plays into this: NiMH voltage drops quickly from ~1.35V to ~1.2V, then holds a flat plateau for hours. With the microamp draw of a CdS meter, that plateau stretches to weeks.

Practical note: if your camera has a battery check dial (OM-1, Minolta SRT), it's calibrated to 1.35V. The V80H will always read "low" there — even with a full charge. The exposure meter itself works fine. Also, NiMH struggles below 5 degrees C — for winter shooting, zinc-air is the better choice.

On capacity: 80mAh concerns are understandable. But in context, a CdS meter draws so little current that capacity isn't the limiting factor. The V80H is best suited for photographers who shoot regularly. If your camera sits in a case for six months, alkaline + ISO correction is the right call.