This MR-9 Battery Adapter is designed by Kantocamera in Japan and is a very simple and useful solution for replacing certain mercury batteries that cannot be made any longer and are used in several analog cameras.
The adapter can be used for the replacement for the discontinued MR-9, H-D, PX13 and PX625 mercury batteries. It has the same size as the original battery so no additional modifications are required (apart from certain exceptions).
It also has a built-in circuit to reduce the voltage of a SR43(386) battery 1.55V to that of a mercury battery with a voltage of 1.35V. This makes you don’t have to convert your camera anymore.
This voltage transformation adapter can be used with both silver oxide batteries (SR43) and alkaline batteries (LR43). If your camera requires a strict constant voltages it is advised to use silver oxide batteries. Due to erosion or a weak spring, the contact of the battery may be unstable. Keep this in mind. Of course, if the camera is broken, it may not work even if you use a suitable adapter and battery.
The voltage transforming type adapter cannot handle a large current, therefore you cannot use this type of adapter for products which require a large current.