Operating fish finder using lithium battery

[BearLakeFishGuy]

My finder is a Garmin 9" Echomap (very similar to the 9" Lowrance and Birds). They draw about 1.5 or so. That would give you WAY more life than 3-4 hours. If you had a 50Ahr battery, it should last about 30 hours! You can't fish that long in one day! Quit worrying so much and just fish. You've taken the necessary precautions.