PX400 Battery & Adapter for Pentax Spotmatic SP SP, SP-II, SP-IIa, 500, 1000

• Replaces outdated PX400 batteries: Allows the use of modern and affordable zinc-air hearing aid batteries (type P312).
• Precise exposure measurement: Zinc-air batteries provide a constant voltage of 1.35V, which is ideal for the original light meter of your camera.
• Easy to use: The rubber ring perfectly and securely centers the smaller battery in the camera's battery compartment.
• Cost-effective solution: A simple and reusable alternative to expensive modifications or hard-to-find batteries.
• Practical 2-piece set: You receive two adapter rings so you always have a spare on hand.

Scope of delivery:

• 2x rubber O-ring adapters
• 6x batteries type p312

Technical specifications:

• Adapter for: zinc-air battery type P312
• Replaces: PX400 / EPX400 / V400PX / RM400
• Voltage (with P312 battery): 1.35V

Description:

This simple rubber ring adapter is the perfect solution to power your classic Pentax Spotmatic or another camera that originally required a PX400 mercury battery. Since the original batteries are no longer manufactured, this adapter allows the use of affordable and widely available P312 hearing aid batteries. The ring ensures that the smaller battery is centered in the compartment and makes reliable contact.

Note on battery voltage:

The voltage of the batteries is stated on the package as 1.45 V (see last image). However, when measuring the voltage under load, you get about 1.35 - 1.37 V, which is very close to the ideal. The great advantage of these batteries is also that they maintain a constant voltage over a long period – making them a good replacement for the original PX400.

Compatibility

Suitable for the following cameras that require a PX400 battery:

• Pentax Spotmatic SP, SP II, SP IIa, SP500, SP1000
• Fuji/Fujica ST601, ST701
• Honeywell Spotmatic SP, SP II, SP IIa, SP500, SP1000
• & many more ...

Note: The Pentax Spotmatic F requires a PX625 adapter (sold separately).