Quote Originally Posted by Monophoto
The Wein air cell is supposed to be the best replacement, but it has a problem. It uses the same technology used in the batteries used in hearing aids - they are sealed at the factory, and the seal must be removed when they are installed. Once the seal is removed, the life of the battery is brief - a few days at most. That may be what the dealer installed for you.
I have used Wein air cells for periods of months in a 124G, Olympus OM1 and Luna Pro. I have found that the best way to handle them is to buy a mess of the hearing aid cells that they are based on and when they do expire, swap the cells out of the washer that makes them fit in the camera. I forget which cell it is, but there are very cheap hearing aid batteries that fit like a charm and cost very litle.

If the packaging says that the battery is 1.5v, it is not the Wein air cell. I am more inclined to think that he sold you a battery that was about dead. Hopefully that is all it is and not a meter problem that has decided to crop up just now. Theoretically a 1.5v battery will give you less than optimal results, but it should be pretty close.