PX27 Battery Adapter Set for Minox 35 GT, EL, GL

• Stable voltage until shortly before depletion: SR44 silver oxide cells deliver 4 x 1,55V = 6,2V with a flat discharge curve, almost identical to the original PX27 mercury battery. No gradual drift as with alkaline (LR44).
• Fits without tape: The adapter holds the four SR44 centred in the battery compartment. The stack is a good 1 mm taller than the original cell, and the sprung contact in the screw cap of the Minox 35 takes this up.
• Ready to use right away: Four matching SR44 cells are included with every variant: insert them, screw the cover on, keep shooting.
• Refills without special cells: When the cells are empty, you only replace the four SR44, and the adapter stays. SR44 (also called 357) is a common watch battery.

Compatibility

Suitable for various cameras, including:

• Minox: 35 EL, 35 GL, 35 GT, 35 PE, 35 PL, LX [...]
• Rollei: 35 LED
• Agfa: Optima 335, Optima Sensor Flash
• Hanimex: VEF Zoom

Not suitable for Minox 35 ML, MB and M.D.C. (these require a PX28 adapter).

Also not suitable for the Minox C, EC and ECX or the Rollei A110 and E110. Four SR44 are too tall for these, as customers with the C, EC, A110 and E110 have reported to us.

For the Rollei 35 SE and 35 TE there is the square PX27 Rollei adapter.

Also not suitable for the late Minox 35 models from 1988 onward: GT-E, GT-E II, GS-E, GT-S, GT-X and Goldknopf Edition. Their built-in battery holder takes two CR 1/3N cells with a diameter of 11,6 mm. At around 13 mm, the adapter sleeve is too thick for it. The matching battery: CR 1/3N lithium cell.

Not sure whether the adapter fits your camera? Complete list of all cameras that take the PX27 battery type.

Scope of delivery

• Standard: 1x PX27 adapter + 4x SR44 batteries
• Set: 1x PX27 adapter + 4x SR44 batteries + 2x ISO badge (replacement)
• Complete: 1x PX27 adapter + 4x SR44 batteries + 2x ISO badge + 1x filter adapter 30,5mm

Technical details

• Adapter material: engineering plastic
• Colour: black
• Adapter outer diameter: around 13 mm
• Height with 4x SR44: 21,6 mm (original PX27: 20,5 mm)
• Battery system: 4x SR44 silver oxide (1,55V per cell, 6,2V total)
• Replacement for: PX27 / V27PX / 4SR43 / EPX27

Description

The Minox 35 GT, GL, EL and PL originally required the PX27 mercury battery with 5,6 V, and since the mercury ban there has been no identical replacement for it. This adapter holds four SR44 silver oxide cells and keeps them centred in the battery compartment. Together they deliver 6,2 V with a flat discharge curve. At 21,6 mm, the stack is a good 1 mm taller than the original cell (20,5 mm). In the Minox 35, the sprung contact in the screw cap compensates for this, and the cover closes without any effort.

The typical workaround, wrapping four button cells in tape and hoping the stack fits, is error-prone and leads to contact problems. Besides the Minox 35 models with PX27, the adapter also fits the Rollei 35 LED, among others.

Practical tips

• Inserting: Place the batteries in the adapter, put the adapter in the battery compartment and screw the cover shut. The adapter ensures the correct polarity.
• Transport protection: Place the included insulating disc between the adapter and the battery compartment contact if the camera will not be used for a longer period. This prevents self-discharge.
• First film: For the first film after changing the batteries, use ISO 400 negative film. Its wide exposure latitude forgives slight deviations while you get a feel for the exposure.
• Buying replacements: SR44 batteries (also sold as 357, SB-B9 or SR44W) are available everywhere. You are not tied to any specialist supplier.

Alternative designations for this battery type: PX27, V27PX, 4SR43, S27PX, PX27S, RPX27S, PX27A, 4LR43, A27PX, 4AG12, U27PX, V7150, Varta 7150, L7150, EPX27, KX27, RPX27, H-4N, MER27, HS3C, 1413MP, 4NR43, VPX27

Want to know more about battery alternatives for analogue cameras? In our FAQ article on batteries and adapters we explain all the options in detail, including a voltage comparison and recommendations by camera type.

Frequently asked questions

“Do 4x SR44 even fit in the battery compartment?”

In the Minox 35 with PX27 (EL, GL, GT, PE, PL), yes. Four SR44 add up to a height of 21,6 mm, while the original PX27 was 20,5 mm tall. The adapter does not change this height: it is a sleeve that holds the cells centred in the compartment. The sprung contact in the screw cap of the Minox 35 takes up the good extra millimetre, and the cover closes normally. It is tighter in cameras whose compartment has hardly any spring travel. Customers have reported to us that the stack is too tall in the small Minox C and EC as well as in the Rollei A110 and E110. The adapter is therefore not suitable for these cameras, nor for the Minox ECX. Four LR43, on the other hand, would be too short at 16,8 mm and rattle around.

“6,2V instead of 5,6V, is the exposure still correct?”

Practical tests and community experience show: the Minox 35 series works at 6,0–6,2V without any relevant exposure deviation in normal daylight. In low light conditions (dusk, indoors), a slight tendency towards underexposure can occur. If you want to play it safe, adjust the ISO down by one stop. Negative film easily handles this minimal difference.

“Why SR44 and not alkaline (LR44)?”

The original PX27 was a mercury battery with 5,6V and an extremely flat discharge curve. The automatic exposure of the Minox 35 works without an internal voltage regulator. It responds directly to the applied battery voltage. SR44 silver oxide cells deliver 4 x 1,55V = 6,2V with a similarly flat curve: the voltage stays stable until the cell drops off steeply at the end of its service life.

LR44 alkaline cells start at 4 x 1,5V = 6,0V and then drop continuously. At first the exposure is right, after a few weeks it no longer is. In analogue photography forums, Minox owners regularly report deviations of about one stop when using LR44, without knowing that the battery is the cause.

“Wouldn't 2x CR1/3N lithium be enough?”

2x CR1/3N add up to 6,0V with a flat discharge curve, a good alternative on paper. In practice, photographers report CR1/3N cells that deliver undervoltage straight from the factory (2,7V instead of 3,0V). Especially from cheap suppliers and marketplace counterfeits. As a standard watch battery, SR44 is too cheap to be worth counterfeiting. This risk is eliminated. It's different with the late Minox 35 models from the GT-E (1988) onwards: there, 2x CR 1/3N is the battery type specified from the factory, and this adapter does not fit their battery holder.

“Why not just buy a ready-made PX27 replacement battery?”

That works as long as you can get one. The PX27 replacement cell from GoldenPower, for example, consists internally of four LR43 alkaline cells in a housing. Its voltage drops over time, and the smaller LR43 have less capacity than SR44. When such a replacement cell is empty, you buy the whole unit again. With the adapter, you only replace the four SR44.