Funny you mention that I've never gone below 13 with the car running especially after I relocated my battery and did 0 gauge wiring. My disc reads 15 driving around now and never goes below 13.8 Now. In traffic with my 1000w and 2 12's. But if I sit with the car off and amp on it will drain of course but not past 12 the dic displays power saving mode and shuts off