I was using my brand new Vaquero yesterday morning and it started acting up within the first hour or so. I have about 10 hours on the detector and after checking everything I could think of, I came to the conclusion that I had a bad coil. I was going to call the factory this morning, but I live in Ohio and the factory is several hours behind on the time. After rechecking the detector this am, I was sure it had a bad coil. Before sending it back, I decided to check the battery and it showed 16 miliamps. A new one checked in at 26. I put a new battery in and the detector was perfect. I had neglected to check the battery because I had so few hours on the detector. I learned my lesson. Always check the obvious and don't assume that a battery is in good shape even when it is nearly new. Funny thing to add. I always carry a spare in my pouch and when I dragged this brand new, unused, in the package battery out, it had an expiration date of 2007. I had failed to rotate my stock and when I checked it on my tester, it was completely DEAD! It might have been 15 plus years old.