Battery set up question

[Dog-Boss]

Newbie here. I'm converting a jon boat to more of a bass boat. I want to run 2 batteries. 1 for accesories and 1 for the 12volt 55lb Minnekota trolling motor. What I'm trying to figure out is how to have the ability to use a 1 , 2 all or none switch (or another set up) and be able to switch from battery 1, should it die while trolling, to battery 2 with a selector switch?
I plan on using a 12 panel fuse block for accessories.
I am trying to think how can I switch the batteries without having to un hook cables and swap them that way. I'm thinking it may not be possible because each battery is essentially running 2 different types of electroinc(s) hope this makes sense. Thanks in advanced.

 

[MN Fisher]

Do you want to have the accessories running at the same time you're running the TM from the 'backup' battery?

If so - two cables from each of the 2nd battery's posts. One pair goes to the accessory fuse panel, the other to a standard 1/2/off selector switch
Cables from the primary TM battery also run to that switch.
Put a 60amp fuse or circuit breaker after the switch...then to the TM.

Note that some TM's put out RF interference if they're running off the same battery as the sonar - so if you're running the TM off the secondary battery, your sonar might get a little fuzzy when the TM is operating.

 

[Dog-Boss]

MN Fisher....short answer yes...I drew a diagram hoping that this is a picture ofbwhat you described.
Yes?

 

[MN Fisher]

MN Fisher....short answer yes...I drew a diagram hoping that this is a picture ofbwhat you described.
Yes?16413534662891344025012665727324.jpg

Yep - that looks right far as I can see.

 

[user 26281]

MN Fisher....short answer yes...I drew a diagram hoping that this is a picture ofbwhat you described.
Yes?16413534662891344025012665727324.jpg

Looks good, just a few comments.

1. Your (-) bus bar needs to be rated pretty high since all the current will be going throug it.

2. The switch shows a both position. This will put the batteries in parallel. Its generally not good to have different types/ratings/age of batteries in parallel. Emergency or short duration use should be OK.

3. Make sure you use correct size wire for + and - leads.

 

[Dog-Boss]

Thanks guys. I plan on using 6 awg wire for the batteries and step down to 8awg where the trolling motor, from what I've read that's what needs to be done since I'm traveling more than 5 feet to the tm and the fuse panel.
I won't use the both position as I'm aware of that 24volts and how it will not be a good day.
I have attached a picture from Minnesota on how to wire where both batteries linked but still 12 volts...any thoughts on that set up and what I want to do?

 

[MN Fisher]

I have attached a picture from Minnesota on how to wire where both batteries linked but still 12 volts...any thoughts on that set up and what I want to do?

Ya, i noticed the 'Both'

Hooked that way, you'll run the batteries in parallel when switched to 'Both'...this isn't normally an issue as it just adds the current together. But to insure battery safety, you'd want both batteries to be the same.

Otherwise, just a 1/2/off switch would work best in that situation.

 

[Dog-Boss]

Funny.....not sure where I got that switch idea from... lol . I mean to use a 1/ 2 /off switch. . Thanks again