bs, its been a while since I checked so I'm not sure they're still available, but the right way to use a pair of, IIRC, SR-44s in a Lunapro that wants mercury batteries is to put then in Gossen's own adapter. While you're at it, you might as well send the meter to Gossen's US distributor -- used to be Bogen, now called Manfrotto and I think they're still it -- for a complete overhaul. Contact them.