Olympus ECR 35 battery check light

I purchased (2) MR-52 battery adapters along with (2) 1.35 v zinc- air cell batteries for my Olympus ECR 35. When I slightly depress the shutter release for the 'battery check' condition the light illuminates and then dims. The shutter still operates following the check. I'm just curious as to what is going on. Any ideas ?
Previous to this I had the stacked batteries, with foil in one side. I was hoping to get the original 1.35 volts with the MR-52 setup.