too much stuff on the starting battery?

[hriley010]

Hey guys, I have a new question now. I have three batteries in my bay boat. One is hooked to the big motor and the other two are set up for twenty four volts. So I have the live-well, Humminbird 797 and bilge pump hooked up to the one battery on the big motor. On the two hooked together there is just one battery cable going from the positive terminal to the negative terminal on the other battery. Then the positive cable from the trolling motor goes to the positive terminal on one battery and the negative cable goes to the negative on the other battery.

What I want to know is can I hook my electronics to one of the trolling motor batteries as long as they are not hooked into the 24v system. In other words, just one battery?

The reason I ask is that my battery that starts the big motor died today and I had to use a trolling battery to get back to the dock.

Thanks,

Harold

 

[Silvertip]

Re: too much stuff on the starting battery?

Yes you can but you need to be careful. Here is a diagram.

 

[Wee Hooker]

Re: too much stuff on the starting battery?

Do you run your livewell or bilge pump allot? Your Humminbird draws less than 1 amp so that alone sould take a LONG time to drain your starting battery. Not saying you shouldn't move the loads, just that you might also have a weak starting battery/ problem with your outboard charging output. Especially true if it's just happening now after a period of time.

p.s. (Silvertip?,) Correct me if i'm wrong but wouldn't it also be possable to add a switch to allow starting on either of those trolling motor batteries as a back-up?

 

[Silvertip]

Re: too much stuff on the starting battery?

Yes you could jump or switch off either battery. HOWEVER -- if there is even a remote chance that the 24 volt system ground and the engine ground come together, you get 24 volts into the engine and -- well, I'll just let you think about that. You would be perfectly safe using the battery on the left.

 

[hriley010]

Re: too much stuff on the starting battery?

thanks guys for all your input... i do understand the what you are describing. i just wanted to make sure before i did it because i had my fishmark 320 hooked to one of the trolling batteries and it would not power on. i have since discovered that the fishmark 320 was going bad. when i get the batteries in the boat i'll try this method out and repost. i got a battery desulphator so the batts are getting conditioned right now.

once again, thanks to all for the input.