Question About Battery Power and Electronics

Hey guys, I have a question for ya'll. First let me give you some information that might help with the assessment of my problem.

I recently had 2 Helix 7 depth finders installed in my Crestliner; both with down imaging, but only one with GPS. My Crestliner has three batteries, two for the trolling motor and one for cranking. I do not know which battery or batteries power the depth finders since I had them installed. Ever since the install I get a low voltage message on both of my depth finders after 5-6 hours of fishing. Before having the Helix 7s installed, I had 2 depth finders without down imaging and one of them had GPS, but never got a message about low voltage. Also, I have not noticed the trolling motor slowing down any, nor have I had a problem cranking the 90 HP.

My question is, does the Helix 7s with down imaging draw that much more power? Or do ya'll think I may have a problem with the battery or batteries that power the Helix 7s. Do I need to invest in bigger batteries?

Mr. Bruce, if you think this needs to be moved somewhere else it is okay. I just know that there are some pretty sharp folks on the La. forum and one of them may have an answer for me.

Thanks, in advance, for the help. Even if you don't know, thanks for reading my post.

Your electronics are usually powered by your cranking battery. I added an 1199 this year and eventually my big motor. (150hp) failed to start on 2 occasions when I had been on the water for 7-8 hours. I replaced my starting battery and resolved the problem.

You could have your cranking battery tested under a load at an auto parts store to determine if it is weak. Sometimes batteries will fully charge but the charge they hold is reduced due to sulfation of the lead plates.

Pastor, I recently installed one Helix 7 DI/GPS and have received the same warning after trolling for only an hour or two. I believe there is no actual problem other than needing to go into the settings and change the low voltage warning to a slightly lower threshhold as my actual voltage as read on the other depth finder is 12.3 volts.

Electronics are supposed to be connected to the cranking battery.....they should also be connected direct to the battery and not wired into something else.....they need there own dedicated wire with a inline fuse......and if the wire is too small you will get a low voltage reading.

You need to check what G said first, and fix that if they are not wired directly to the battery. Then do what RMGeorge said and set the voltage setting down lower.

The first thing I would do is take a voltmeter and see what the voltage really is. That will tell you if it is a batter problem or a problem with the electronics. If the battery voltage is ok then you might want to check to see if you can change or turn of the low voltage alarm. If it work right then I would not care what the voltage is as the best indication of good voltage is proper operation of the device. Then you might consider reconnecting things if you want to.

its OK here......hope you figure out your problem.......

I have found that with a lot of electronics running it is a good idea to have at least a 1000 cranking amp starter battery with as much reserve capacity as possible. I also charge mine at home after each trip and don't count on the motor to keep it full. If I am fishing about 90% or more and only running a little and am running the livewell with the electronics I occasionally start the motor and let it run a little to pump up the battery.

Thanks, guys, for all of the replies. I'll start checking things out this next week.