multiple batteries

[jdhgcb]

I have a 99 tracker, and it has 3 batteries in it. 2 deep cycle and 1 starting. my question is what things should be powered by which battery? The PO has the trolling motor on one deep cycle, and Everything else on the starting. It seems a little backwards to me, but I am no expert. my thoughts are that the accessories (fish finders, lights, trolling motor, etc) would be on the deep cycle, and the starting battery exclusively for the starter. no point in having continuous use items on a cranking battery. Plus having 2 trolling batteries would give me an extra battery if the first deep cycle ran low on a long trip. however the alternator only charges the cranking battery so is the idea to start the motor every so often to keep it charged as the lights and all drain it? If i was on a night fishing trip using stern lighting and fish finders for the night i would not want that cranking battery going dead, however I don't hear the other guys starting their motors throughout the night. What do you guys do? I don't want to be the *** stranded on the water because I didn't have the batteries set up right.

 

[Scott Danforth]

Re: multiple batteries

is this a 24 volt trolling motor or a 12 volt?

if the trolling motor is 24 volt, then they two batteries will be for the trolling motor and everything else on the starting battery.

 

[coastalrichard]

Re: multiple batteries

You're on the right track. Put the cranking battery on the starter, the trolling motor on one deep cycle and everything else on the other deep cycle. Maybe consider a switch for the deep cycles for use and charging.

 

[jdhgcb]

Re: multiple batteries

yeah the trolling motor is 12/24 volt. i am running it on just 12. I was more questioning the use of the cranking battery for the accessories.

 

[coastalrichard]

Re: multiple batteries

Nah...you want that one to stay isolated and fresh. I never want to hear click, click when I turn the key

 

[jdhgcb]

Re: multiple batteries

that is EXACTLY my point. So i think i will either use all 3 with the starting by itself for the starter. then the trolling motor on one and the rest on the other or trolling and accessories on the deep cycle with the second deep cycle as back up. is there any way to get the alternator to charge ALL the batteries?

 

[Silvertip]

Re: multiple batteries

Whether an engine can keep TWO batteries charged much less THREE of them depends on the size engine you have and the output of the alternator. Look at it this way. If your trolling motor is about a 50# thrusst unit it willd raw about 40 amps maximum. Therefore if your engine has an alternator that outputs 40 amps max (and I'm guessing it doesn't) you would need to run wide open for over an hour to replace that current used by the JUST the troller. I'm guessing you have a 75 - 90 HP engine which will typically have less than a 20 amps alternator. That puts y0u at 2 hours wide open run time. So by now you should get the idea why the boat is wired the way it is. Again, most people get so paranoid about having a dead starting battery that they overlook the obviouos. Gee Whiz, you have two other batteries. Leave the wiring alone and carry a set of jumper cables. Unless you have a killer stereo or a bunch of other high current draw items, there is no reason to pull the accessoeries off the starting battery. What you really need is a two or three bank smart charger that you plug in to AC power at the dock.