OK so I use various electrical devices on my SS pipsqueak but in the end I know less then jack shit when it comes to the various draw rates for different electronic devices place on a marine battery! My little boat has always run a 30 pound thrust minkota till the day was gone and kept going long after. But the other day I did something I should have known better then to do and that is I set out with a brand new never used 29DC ever start battery(I did top it off first) a just out of the box helix7 and a new 54 pound watersnake trolling motor with three blades not two. I was on a small lake east of town and knew full well the new setup would tax the battery more.....but was not ready for what happened. I have run little boats like this for the last 25 years and when the charge starts to go you start to see a slow down but still have around a twenty to thirty minute window to get back. That's not what happened on sunday. on sunday around three hours in I suddenly realized the boat had gone from full speed (around 3 mph as I was 3D mapping with the side scan) to about 60%. This slow down happened in probably under ten seconds. I instantly turned towards the truck that was a half mile away but within another ten seconds i knew that that was not going to happen as I lost 50% of what speed i still had and the sonar said it was time to go back to sleep. In the end from first hint the battery was getting low to full stop I was able to cover only around 150 yards. Luckily for me the boat is very lite and is just loaded into the box so all I had to do was walk a half mile back and drive into the pasture and load up.
Having crap for knowledge in this area I'm just curious on things like how far down on the volt meter can I take a battery before a 12 volt system shuts down since I can set an alarm on the sonar to warn me? How much battery does a bigger sonar unit use over the course of a few hours? Needless to say the sonar played a part but the new motor probably took the Lions share of the juice. I'm sure I could find the answers by Googling it but with not much electrical experience it would take much longer to truly understand what I was looking at and that's why I'm asking you guys hoping you could break it down into much simpler terms! The obvious solution is just to throw a second battery in but with the small size of the boat that's not necessarily my favorite option so just trying to get an idea how the math actually works with this type of setup.
Any tips or past experiences would be greatly appreciated.
Having crap for knowledge in this area I'm just curious on things like how far down on the volt meter can I take a battery before a 12 volt system shuts down since I can set an alarm on the sonar to warn me? How much battery does a bigger sonar unit use over the course of a few hours? Needless to say the sonar played a part but the new motor probably took the Lions share of the juice. I'm sure I could find the answers by Googling it but with not much electrical experience it would take much longer to truly understand what I was looking at and that's why I'm asking you guys hoping you could break it down into much simpler terms! The obvious solution is just to throw a second battery in but with the small size of the boat that's not necessarily my favorite option so just trying to get an idea how the math actually works with this type of setup.
Any tips or past experiences would be greatly appreciated.