Hello, new to the forum, just bought a Gossen Luna-Pro (typo in the title!). Needle moves slightly, but won't hit up to the red marker when I run battery check. So I am guessing it needs new batteries. I removed the old ones, and they are corroded, but the battery chamber itself is fine. I looked for what information I could on this, but I am not confirmed with any of the information. 1. It can take wein cells? 2. you can buy hearing aid batteries (675?) and place them in the original washers and use those? Any help is appreciated.