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Precise exposure with 1.25–1.30V: Voltage close to the original — safe for negative film. No misexposures caused by too high alkaline voltage in CdS light meters.
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One battery for years instead of disposables: The V80H is rechargeable via USB-C. No more expensive zinc-air cells that dry out after weeks.
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Ready-made charging station instead of tinkering: Own PCB board, USB-C connection, housing with spring contacts. Plug in, charge, done.
Battery compartment in the film chamber? No problem.
In cameras like the Rollei 35 or Leica CL, the battery compartment is inside the film chamber — every battery change means: remove the film. With the Pro Pack (2x V80H), you can simply change the battery with every film change. No extra opening, no risk to the film.
Scope of delivery
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Standard: 1x USB-C charger + 1x V80H battery (PX625-compatible)
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Pro Pack: 1x USB-C charger + 2x V80H batteries
Technical data
- Battery: Varta V80H (Low Self-Discharge NiMH, 80 mAh)
- Nominal voltage: 1.2 V (according to manufacturer)
- Operating voltage (plateau): 1.25 – 1.30 V
- Capacity: 80 mAh — sufficient for weeks at microampere consumption of a CdS meter
- Charging method: Gentle slow charging (C/7) via USB-C
- Charging time: approx. 8 hours (overnight charging recommended)
- Charger material: Technical plastic
- Connection: USB-C (PD-compatible)
Description
Many classic analog cameras — Rollei 35, Leica CL, Olympus OM-1, Canon F-1, Minolta SRT — were designed for the 1.35V mercury battery PX625. Since the production ban, there has been no perfect replacement solution. The most common alternative (1.5V alkaline) delivers too high a voltage, which especially leads to misexposures in CdS light meters.
The Varta V80H solves this problem with an operating voltage of 1.25–1.30V, which is much closer to the original. It is not an ordinary NiMH battery: The V80H comes from Varta’s industrial "Robust" series (built for server RTC and medical technology) and uses LSD-NiMH technology (Low Self-Discharge) — its self-discharge is comparable to the Eneloop series.
The idea to use a V80H as a PX625 replacement comes from Troeszter.net. Building on that, we developed an independent product: own PCB board, USB-C instead of lab power supply, housing made of technical plastic with spring contacts.
Common concerns — and our answers
“1.2V is too low — the original had 1.35V”
The nominal voltage on the datasheet is the average over the entire discharge cycle. Our measurements in a Rollei 35 show: freshly charged, the V80H delivers 1.30–1.32V. After two weeks still 1.27–1.28V. The deviation of 0.05–0.08V is within the tolerance range for negative film.
“Only 80 mAh capacity — that’s not enough”
A CdS light meter consumes microamperes. At this current consumption, the stable voltage plateau of the V80H lasts not hours but weeks. 80 mAh is little for AA batteries — for a camera button cell it is sufficient.
“NiMH discharges by itself”
Standard NiMH loses 10–20% charge in the first days. The V80H is not standard NiMH. As an LSD cell (Low Self-Discharge) from the Varta "Robust" series, it retains about 80% capacity after one year at room temperature — comparable to the Eneloop series.
Practical notes
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Battery check: Many cameras (OM-1, Minolta SRT) have a battery check calibrated for 1.35V. The V80H shows "empty" there — although the light meter works perfectly. This is normal.
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Cold: Below 5 degrees Celsius NiMH becomes unreliable. For winter shots in frost, a zinc-air cell or alkaline + ISO correction is the better choice.
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After charging: Let the V80H rest for 1–2 hours after charging before putting it in the camera. The resting voltage stabilizes during this time.
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Power bank: Some power banks switch off at low current consumption. The charger requires a USB source that does not switch off small loads (power supply or laptop port).
Detailed comparison of all PX625 alternatives
We wrote a technical guide comparing all options: alkaline, zinc-air, Schottky adapter, V80H, and DIY solutions — with measurement data, practical tests, and community feedback.
To the complete PX625 guide →
Note: Please charge the V80H battery only in the charger designed for it. Charging indicator: The blue LED shows that the USB-C cable is connected. There is no full battery indicator — a full charge takes about 8 hours.
Compatibility
Fits various cameras, including:
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Canon: Canonet series (QL17, QL19, 28, G-III), F series (F-1, FT, FTb, FX), Demi / Dial series [...]
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Nikon: F series (F, F Photomic, FTN), Nikkormat / Nikomat series (FT, FTN) [...]
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Minolta: SR-T series (100-303, MC, SC, Super), SR series (1, 7, 100-505), Hi-Matic series (7, 7S, 9, 11) [...]
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Olympus: OM-1 series (OM-1, MD, N), 35 series (RC, RD, SP, DC), Pen series (F, FT, D2, EED) [...]
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Pentax: K series (K2, KM, KX), Spotmatic F, H series (H1a, H3v) [...]
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Rollei: 35 series (35, 35S, 35T, Classic), SL35 series (SL35, SL35M, SL350), XF35 / A26 [...]
Not sure if the battery fits your camera?
Here is a complete list of all cameras compatible with the PX625 battery type.
