How many batteries? HELP!

[Stcroixshimano]

New member and 2nd year boater here. Tried to figure this out myself but I keep 2nd guessing.

Here's what I got-
2001 17 ft Nitro w/90 horse
older hummingbird
livewell
crappy radio
12V trolling motor
2 batteries
single bank charger

here's what Ive bought and have sitting in boxes-
hummingbird w/side imaging & GPS (keeping old one as well)
better radio and speakers
dual halogen lights
3 batteries total
3 bank noco genius charger

was getting ready to start installing when I got my hands on a 24V minn Kota w/ auto pilot

now what do I do!?
Do I need a 4th battery?
I'm pretty sure I need 2 deep cycles for trolling motor only and I can not add anything else to those batteries.
Pretty sure I have too many accessories to add to cranking battery.
So I need 1 more deep cycle for all the accessories.
And a cranking battery for just the motor.
But I only have a 3 bank now.

Should I hook up the charger to the 3 deep cycles and count on the alternator to keep the cranking battery charged?
Will this work?
Also I would like a back up plan for a dead cranking battery. Is there a safe way to jump the motor off any of the 3 deep cycles?

Pulling my hair out here. Just want to get it right.

Let's go fishin

 

[Lyle29464]

Re: How many batteries? HELP!

silver knows this stuff better than most. He will set you straight. I would think about putting the house batteries in series for the 24 volts you need, pick up the 12 volts ahead of the 2 nd battery. To charge the second battery you will need to discount it from the first one.

 

[j_martin]

Re: How many batteries? HELP!

Standard setup.
1 battery is for cranking, and running your accessories. Crappy radio, depth sounder, bilge pumps, and even live well pumps. Engine will maintain it good enough to get you home.

2 batteries hooked up in series, with a center tap for the trolling motor. You can discard the 12/24 switch if you have one. Look up the trolling motor wiring for the connector hookup. Don't forget the recommended circuit breakers. Trolling motor circuits will start a grand fire in a hurry if unprotected and they get shorted out.

Hook one output from the charger to each battery.

Carry a short pair of heavy jumper cables to jump from either trolling motor battery to the main battery in an emergency. I only did this once. I had a totally fried starter motor drain the main battery. With jumpers it started anyway and got me home.

hope it helps
John

 

[JohnnyFire]

Re: How many batteries? HELP!

Ok i have gone through a few diagrams in my head and on paper. what it comes down to is: Check image for wiring diagram.
you will need a Shore/Gen Phase switch its like 6 breakers in one but linked so you cant only turn on 3 at a time so as to not create a short.
the only down fall is as long as its in the position to run the troll motor your two batts to make the 24v will not be charged by the engine until the switch is slide and the other 3 are turn on. (as one)
if you have any questions let me know all messages are forwarded to my phone.

PM me if you like i can order the parts for at cost. the isolator and shore gen Breaker Switch

http://i15.photobucket.com/albums/a360/trig55/scan0001.jpg

 

[Silvertip]

Re: How many batteries? HELP!

I'm doing this with a patch over one eye and a bunch less than "pain free" I'll tackle it anyway. Scrap your plan and especially isolators -- you don't need them and your three bank charger will work fine. My suggestion is to add the fourth battery. Here's the deal:

Two batteries wired like this for the 24 volt trolling motor. Note that only two of the three available banks from the charger are used. We'll use the third in the next diagram.

The starting and starting backup battery get wired to a dual battery switch (about $30) as shown.

Now follow this carefully. ALL loads (meaning the feed to the fuse panel) gets disconnected from its current source and connected to the COM terminal on the switch (which is not shown in the diagram). If you have an automatic bilge pump put it directly to either battery. The third bank from the charger also gets connected to the COM terminal on the switch and the ground wire goes to either battery negative.

At the dock you plug in the charger and the two troller batteries get charged. The third output from the charger feeds the COM terminal on the switch so if you set the switch to BOTH, both starting batteries get charged although it will take longer than charging either one individually. You can do that by selecting BAT 1 or BAT 2.

On the water, you will normally designate BAT 1 as your primary starting battery, with BAT 2 as the backup. So set the switch to BAT 1 OR BOTH and go boating. Remember, whatever position you have the switch set to is what will be running the accessories and also which battery is being charged. When you anchor with the intention of fishing and listening to tunes, etc. set the switch to BAT 2. This takes BAT 1 off line so it will stay isolated. When ready to do switch back to BOTH and go, OR leave it on BAT 2 and go. This way BAT 2 (the one you had been using) will be charged. If BAT 2 won't start the engine, switch to BAT 1 since it had been isolated and when the engine is running, THEN switch back to BAT 2 to charge it. This is the simplest, least expensive, and most versatile setup you can have. There are a many other ways to do this including use of an ACR if you are "switch challenged".

 

[2 Eagles]

Re: How many batteries? HELP!

You only need three 2 Deep Cycle and 1 Cranking. Hope the attachments help.

 

[Stcroixshimano]

Re: How many batteries? HELP!

Thanks for all the quick replies everyone. Posted this same ? on another boat forum at same time and I got 0 replies. Must be a yacht club or something.

I think Silvertips plan is perfect for what I want. By the way sorry about the eye. I really appreciate the detailed response you gave me.

Know exactly what I'm doing with the troller batteries.
As far as the other 2 batteries I understand now how to hook them together with the Battery Switch.
But by ALL LOADS to COM terminal are you telling me to hook all power wires from the accessories to the COM terminal?
Does it matter which of the 2 batteries I hook the ground wires to?

I hear that the fish finder hooked up to the same battery as the motor will cause interference with your signal. Will this be the case now when I'm running both? Would there be any way to correct this problem.

Thanks for helping me. You guys are awsome.

 

[Silvertip]

Re: How many batteries? HELP!

There are so many stories about fish finder interference it's pathetic. Some claim hooking it to the troller battery causes interference. This is the first time I've heard the starting battery causes it. Actually, I've owned and fitted many locators on all sorts of boats and have not had an interference problem on any of them regardless how the owner wanted it. My preference is to wire the locator to the nearest source of power.

To answer your question about what gets connected to the COM terminal I need to know if your boat has a fuse panel or not. If it does, all of your accessories should be connected to it and grounded to a ground bus on or near the panel. Typically there is a pair of 8 or 10 gauge wires running from the battery to the helm to feed the fuse panel. Circuits branch out from there. If you don't have a fuse panel, then every accessory has an in-line fuse which makes for very messy wiring. Regardless -- you either feed the fuse panel from the COM terminal, or you connect all in-line circuits to the COM panel. Hooking them to the battery defeats the purpose of the switch. If you tie circuits directly to an individual battery you cannot run it from another battery. That is exactly why I asked if you were "switch challenged". Some folks simply can't get their arms (brains) around a dual battery switch. It is nothing more than a switch that directs where current comes from and where it goes to. OFF is obviously OFF. BAT 1 means it is powering everything and ONLY it gets charged from the engine or your on-board charger. BAT 2 is the same principle. BOTH is obviously both. Grounds can go to either battery since they tied together anyway.

 

[Stcroixshimano]

Re: How many batteries? HELP!

Silvertip, help!
Took a few days. Don't want to say I think I got it because I probably don't. But I'm getting there.
Old fuse block was a 6 position. I replaced with a Blue Sea 12 position. Purchased a Blue Sea Mini Battery Switch( the one with 3 terminals). Also got battery cables( 4 ga), fuses, connectors, and all the other goodies.
You said fuse panels are usally ran with 8-10 ga wire. But I read where you recomend 6 ga. So that's what I replaced it with. So I need to fuse it 7" from the COM terminal with either an in-line fuse or a circuit breaker. Which do you recomend and how many amps. Fuse block says 125A max. Is that what I should use. Can't find any in-line fuse holders rated over 30amp.
Sence I used 6 ga for fuse block power, should I use 6 ga for fuse block ground? Also the ground goes to either battery negative, right? Last thing about the fuse block, some accesories already have in-line fuses in there power wire, should I remove them and just use the fuses on the fuse block or keep them both?
By the way, should I go with in-line or circuit breaker for my 24V trolling motor?and how big?
Thanks

Hope the eye is getting better.

 

[Silvertip]

Re: How many batteries? HELP!

If you plan to suck 125 amps from the fuse panel, 6 AWG wire feeding it won't cut it nor would two batteries. So lets get real here. Every accessory you have has a current draw rating associated with it. Check the box, the manual, the install instructions, or the device itself for a label or spec that indicates current consumption (Amps). Write down the number for each device. Now add them up. I would hope you come up with a lot less than 125 amps. I suspect you will come up with about 1/3 of that number or less. That number represents the maximum current you will need to pass through the wires from the battery if ALL of those accessories are operating at the same time. The fuse or breaker protecting that circuit should be 10% or so bigger than the maximum load, but must not have a rating higher than the current capacity of the wire or the wire would burn up before the fuse or breaker opened. For most boats #8 or #10 gauge wire is used as the feed and a 20 or 30 amp fuse is used. Since you chose 6 gauge, a 40A or even 50A breaker or fuse can be used but you will never pull anywhere near that current. Obviously if you feed the panel with 6 gauge (red wire) the ground going back to the battery (black wire) must also be 6 gauge. Yes -- your trolling motor also needs a breaker within six inches of the battery. You need to size that one for the max current draw of the motor. See spec sheet.

As for the 125A fuse panel, the reason it says 125 amps is because it has 12 fuse locations. At an average of 10 amps per fuse slot, thats 120 amps. If you look at the specs for your accessories you will find none of them except the troller draws more than 10 amps and most are in the 3 - 5 amp range.

 

[Stcroixshimano]

Re: How many batteries? HELP!

Silvertip you are the man. Thank you for setting me strait on all this. You saved me the $900-$1200 that they wanted to do all this. It really wasn't that bad after following your instructions. It all looks very professional and I'm very pleased with everything.

With the name Silvertip, are you on any gun forums?

If your every around central Ohio and want to go fishing PM me.

Thanks again