Exell MRB400 Zinc Air Battery: Long-Lasting Power for Z400PX, E400N, EPX400, H-B, KX400, PM400R, PX400, RM400, T400N and More Review

Bought for use in an old 35mm camera to power a metering system and prevent false readings from a more modern 1.5V product.

I finally found a battery that works with my dad's old Pentax Asahi SP1000 light meter! This is a small (diameter) battery with a plastic yoke that is somewhat fragile. But it works! The light meter is alive and accurate again!

I got this battery for the same reason as almost everyone here, for a light meter in an old Pentax camera. Unfortunately, the battery was completely empty when we received it. I made sure to read the details on the back of the box, removed the little sticker covering the vents and let the battery sit for hours and the voltage never went above 0.2V. I kept checking with a multimeter and confirmed that the battery was low. Rather than risk those batteries on your old camera, I would recommend…