OK, I have a similar problem. Installed a new battery yesterday, checked it in the driveway and it powered up fine. Went fishing this morning and it worked fine for about an hour then nothing. Even tried to turn it on with the motor running with no success.
Checked the terminals at the connection to the screen and I have 11.93 VDC. Can't get any close to 12 than that! Now I have a portable unit that had a setting where if the battery dropped below a certain threshold it would turn off but I haven't seen a setting for this.
Anyone out there eveer see this? Quite irate right now.
I have a Helix 7 and it is hooked directly to the crank battery. This spring mine did the same thing. Come to find out my battery was going bad. New battery problem went away.
this is good wiring practice anyway to eliminate noise
These newer electronics draw more power than the older ones. I have a direct connect to may battery with 12 gage wire. Keep in mind I am powering 3 units with that wire too.
this could be a battery size problem too- and if you dont correct it, this will damage your unit.