I use duracell batteries but have been thinking about the rechargable ones since they have some now that are 1.6V. When my MXT gets to 10V at start up I notice a difference in how loud the start up beep is so I'm worried about missing those faint deep targets at that point, most rechargables are only 1.2V. Thats only 9.6V at full charge I don't like that fact at all.HH