PX1 battery adapter for Minolta Autocord & Canon QL25 (MR50, LR50)

Fits, among others, the Minolta Autocord and Canon QL25, as well as the following cameras:

• Bell Howell: Dial 35
• Canon: Canonet S, Cine Zoom 512, Dial 35
• Konica: Auto SE
• Mamiya: 16 Automatic
• Minolta: Autocord CDS II, Autocord CDS III
• Olympus: 35 LE

The Canon QL25 comes in two versions: only examples with the large battery compartment, for example from Bell & Howell, take the PX1. Other examples need the PX625, which our PX625 adapter is made for. Measure your battery compartment before you buy: the adapter has the PX1 format of 15.6 mm × 15.6 mm.

Not sure if the adapter fits your camera?
Here's a complete list of all cameras that use the LR50 battery type.

• 1x PX1 / MR50 battery adapter
• 6x zinc-air batteries (type 675)

• Material: engineering plastic
• Color: black
• Replacement for: PX1, MR50, E1N, RM-1N, EPX1, RM1, V1PX, H-P, BMR50, MR850, PX1A, 1A, A1PX, 1100A, PC1A
• Battery needed: only zinc-air type 675 (included), not for LR44 (alkaline) or SR44 (silver oxide)
• Voltage: around 1.4V (stable thanks to zinc-air chemistry, original 1.35V)
• Dimensions: 15,6 mm × 15,6 mm
• SKU: 1397

This battery adapter replaces the 1.35 V PX1 mercury battery (also MR50, V1PX or EPX1) in cameras such as the Minolta Autocord, the Canon QL25 and the Canonet S. It holds a type 675 zinc-air cell that delivers a constant voltage of around 1.4 V, only slightly more than the 1.35 V your light meter is calibrated for.

If you're looking for an LR50 battery for your camera, today you'll only find 1.5 V alkaline cells; the original PX1/MR50 has long since disappeared from stores. Anyone who uses a 1.5 V alkaline battery instead ends up fooling the light meter, and the readings are no longer accurate.

The adapter provides the mechanical fit in the battery compartment, while the zinc-air cell delivers the correct voltage. The matching batteries are included, ready to use right away.

Which battery do I need and how many are included? Zinc-air type 675. Six are included. You can get replacements as hearing aid batteries at any pharmacy or drugstore, usually in a pack of six for under three euros.

Does the adapter deliver the original measuring voltage? Practically, yes. Under the light load of a light meter, zinc-air cells sit at 1.36 to 1.4V, so close to the 1.35V your camera was calibrated for that the exposure stays practically the same. The voltage stays stable throughout their lifespan.

Which cameras is the adapter meant for? It replaces the PX1 or MR50 and fits, among others, the Minolta Autocord and the Canon QL25. Other names for the same cell are E1N, RM-1N, EPX1 and V1PX.