I have been using the cabelas 8 amp/hr battery with my humminbird 383 ( the last time I buy Himminbird by the way) max 6 hrs run time. What is anybody else using  as a power supply or am I just spending too much time on the water?

I also have a 383 unit and I powered  it with a 7.0 a/h battery and it would last at least 24 hours before I had to charge.  This battery went bad and I replaced it with a small motorcycle battery from Wal-Mart 3.0  a/h and have used it  2  times now with no recharge  I have no idea why the run time is so short.