The production and sale of V625PX and PX13 mercury batteries has been forbidden since 1 January 2000 by EU directive 98/101/EC, because they contain a large proportion of the hazardous substance mercury. Diese These batteries are part of the following GOSSEN exposure meters:
LUNASIX, LUNASIX 3 (LUNA-PRO), LUNASIX 3S (LUNA-PRO S), SIXON 2 (C-MATE), SIXTAR (SUPER PILOT), SIXTAR 2, SIXTOMAT electronic, SIXTOMAT 2 electronic (GOSSEN N-100)
Characteristics of mercury batteries
A minimal cell voltage of 1.35 V and a constant voltage level over their entire service life were the most important characteristics of these mercury batteries. Alkaline manganese and silver oxide batteries of identical size and shape with cell voltages of 1.5 V and 1.55 V respectively are not suitable as replacements due to their higher voltage levels, and because the voltage level of alkaline manganese batteries decreases during the course of their service life.
The older GOSSEN exposure meters with cadmium sulfide photoresistor are matched to the above-mentioned characteristics of the mercury batteries. Operation with batteries which have a higher cell voltage may lead to damage or incorrect measured values, beyond which measured values would change during the service life of alkaline manganese batteries.
Replacement by zinc-air batteries
MRB625 zinc-air batteries, which have a cell voltage of 1.35 V and are of identical shape and size as the V625PX and PX13 mercury batteries, are available from WeinCell or Exell Battery as replacements. The smaller MRB675 or PR44 hearing aid batteries can be used with a mechanical adapter as an inexpensive alternative. These batteries are activated before use by removing a protective foil, after which the electrolyte dries out within a short period of time and the battery has to be replaced again. The major disadvantage of zinc-air batteries for amateur photographers is thus their relatively short service life.
GOSSEN Battery Adapter V207A
The battery adapter replaces two no longer available mercury oxide button cells V625PX or PX13 with two silver oxide button cells IEC SR 43 and adapts them both mechanically and electrically to the characteristics of the original batteries. The battery adapter can be ordered via our webshop and, in addition to the adapter, also contains two matching silver oxide button cells IEC SR 43.
Replacement by silver oxid batteries and battery adapter
The commercially available MR-9 PX625 battery adapter, which mechanically and electronically adapts the SR43 silver oxide battery to the voltage and size of the V625PX mercury battery, is a further replacement option. The higher performance SR44 can also be used if the device’s battery compartment is capable of accommodating the slightly thicker battery.
The commercially available MR-9 PX625 battery adapter, which mechanically and electronically adapts the SR43 silver oxide battery to the voltage and size of the V625PX mercury battery, is a further replacement option. The higher performance SR44 can also be used if the device’s battery compartment is capable of accommodating the slightly thicker battery. This adapter is available from, for example, C.R.I.S. Camera Services (www.criscam.com) in the USA and Small Battery Company (www.smallbattery.company.org.uk) in the UK. When buying an adapter, make sure that it also adjusts the voltage because some adapters only compensate for mechanical differences. The use of LR43 or LR44 alkaline manganese batteries together with an adapter is not advisable because the cell voltage of these batteries diminishes considerably during the course of their service life.
The advantage of this solution is the longer battery service life, which however is only made possible by purchasing the relatively expensive adapters for €30 to €40 per battery.
Our recommendation
When buying older exposure meters, be aware that start-up and operation may be associated with considerable costs, and that there’s no assurance that the meter is still accurate due to its age. We therefore recommend changing over to an exposure meter from our current product range.
