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

Fits a wide range of cameras, including:

• Minox: 35 AL, 35 EL, 35 GL, 35 GT, 35 PE, 35 PL, LX Overview of Minox cameras that take the PX27
• Rollei: 35 LED
• Agfa: Optima 335, Optima Sensor Flash
• Hanimex: VEF Zoom

Not compatible with the Minox 35 ML, MB and M.D.C. (these need a PX28 adapter).

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

For the Rollei 35 SE and 35 TE, there’s the angular PX27 Rollei adapter.

Also not compatible with the later Minox 35 models from 1988 onward: GT-E, GT-E II, GS-E, GT-S, GT-X and the 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 right battery for these cameras: CR 1/3N lithium cell.

Complete set with filter adapter: The included filter adapter only fits the Minox 35, and the size you need depends on the model. That’s why the Complete set comes in two versions: one for the GT, PL and PE (32 mm lens barrel) and one for the EL and GL (31 mm lens barrel).

ISO plate for the Minox 35 PL and PE: The ISO scale on the PL and PE only goes up to ISO 400. The plates in the Complete sets go up to ISO 800, so they don’t suit the PL and PE. The plate that goes up to ISO 400 is available separately: ISO sticker for Minox 35.

Not sure whether the adapter fits your camera? Here’s the full list of cameras that take the PX27 battery.

• Adapter material: engineering plastic
• Colour: black
• Adapter outer diameter: approx. 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)
• Replaces: PX27 / V27PX / 4SR43 / EPX27
• SKU: 2144

The Minox 35 GT, GL, EL and PL originally took the 5.6 V PX27 mercury battery, and since mercury batteries were banned there has been no identical replacement. This adapter holds four SR44 silver oxide cells and keeps them centred in the battery compartment.

The usual makeshift fix of wrapping four button cells in tape and hoping the stack fits is unreliable and leads to contact problems. Besides the Minox 35 models that take the PX27, the adapter also fits the Rollei 35 LED, among others.

• Inserting the cells: Stack the four SR44 in the adapter all facing the same way; on each cell, the flat side with the markings is the positive terminal. In the Minox 35, the stack goes into the battery compartment negative end first, with the positive end facing the cover (there’s a plus sign on the inside of the cover to show you). In other cameras, follow the markings in the battery compartment.
• Shipping protection: To keep it safe in transit, the adapter sits on a small holding plate. Slide it off in the direction of the arrow; you won’t need the plate after that.
• Longer breaks: If the camera will sit unused for several months, take the cells out. A leaking cell can corrode the contacts in the battery compartment.
• First roll: After changing the battery, start with an ISO 400 negative film. Its wide exposure latitude absorbs small deviations.

Alternative names 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

Having power problems, such as poor contact or cells that run flat quickly? Our FAQ article on batteries and adapters covers the most common causes and fixes.

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

In the Minox 35 models that take a PX27 (EL, GL, GT, PE, PL), yes. Four SR44s stacked together measure 21.6 mm, while the original PX27 was 20.5 mm tall. The adapter doesn’t change that height: it’s a sleeve that keeps the cells centered in the compartment. The spring contact in the Minox 35’s screw-in battery cover takes up the extra millimeter or so, and the cover closes normally. It gets tighter in cameras whose compartment has hardly any spring travel. Customers have told us the stack is too tall for the small Minox C and EC and for the Rollei A110 and E110, so the adapter isn’t suitable for those cameras, nor for the Minox ECX. Four LR43s, on the other hand, would be too short at 16.8 mm and would sit loose.

“6.2V instead of 5.6V: is the exposure still accurate?”

Hands-on testing and community experience show that the Minox 35 series works at 6.0–6.2V without any meaningful exposure error in normal daylight. In low light (dusk, indoors) there may be a slight tendency toward underexposure. If you want to play it safe, set the ISO one stop lower. Negative film easily handles such a small difference.

“Why SR44 and not alkaline (LR44)?”

The original PX27 was a 5.6V mercury battery with a very flat discharge curve. The Minox 35’s auto exposure has no internal voltage regulator, so it responds directly to whatever voltage the battery supplies. SR44 silver oxide cells deliver 4 x 1.55V = 6.2V with a similarly flat curve: the voltage stays steady until the cell drops off sharply at the end of its life.

LR44 alkaline cells start at 4 x 1.5V = 6.0V and then drop steadily. Exposures are fine at first, but a few weeks later they’re off. Minox owners on film photography forums regularly report exposures being off by about one stop with LR44s, without realizing the battery is to blame.

“Wouldn’t 2x CR1/3N lithium cells do?”

2x CR1/3N give you 6.0V with a flat discharge curve, so on paper they’re a good alternative. In practice, though, photographers report CR1/3N cells that are already undervoltage fresh from the factory (2.7V instead of 3.0V), especially from cheap sellers and counterfeits on online marketplaces. As a standard watch battery, the SR44 is too cheap to be worth faking, so that risk doesn’t apply. The late Minox 35 models from the GT-E (1988) onward are a different story: 2x CR 1/3N is the battery type they were designed for at the factory, and this adapter doesn’t fit their battery holder.

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

You can, as long as you can find one. There are ready-made PX27 replacement cells that are really four LR43 alkaline cells inside a single casing. Their voltage drops over time, and the smaller LR43s have less capacity than SR44s. Once one of those replacements is dead, you have to buy the whole unit again. With the adapter, you only swap the four SR44s.