Hey Jim. I have a 100 ah lithium powering my M15 with depth sounder, ST2000 autopilot, lights, phone and tablet. The autopilot draws about .5 amps in light air or while motoring in flat water. Since you can use 80 percent of the battery capacity, you could use the autopilot for about 160 hours before your battery needs to be recharged. I will test that out this coming summer when I motor the entire length of the Erie Canal from west to east and then return to my start location. Should be about 700 miles. Sent from AOL on Android On Sat, Dec 30, 2023 at 6:40 AM, Jim Sadler<jimsadler@jascopacific.com> wrote: Any of u skippers using lithium ion batteries to power your tiller pilots? What size battery are u using? I would like to get at least 12 hrs on one charge Captain Jim SV Pelican M15 Get Outlook for iOS<https://aka.ms/o0ukef>