Battery Switches & Setups Demistified

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achris

More fish than mountain goat
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Re: Battery Switches & Setups Demistified

Me thinks this thread needs to be retitled

Battery Switches & Setups Remystified

Cheers.....
 

45Auto

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Re: Battery Switches & Setups Demistified

If battery 1 is flat, yes you have the ability to start on battery 2 but under that scenario I want every amp of current going to battery 1 to get it back up.

Guess everybody looks at it differently. I personally want my good battery (battery 2 in the situation above) fully charged because I know it works. Then I'll worry about charging battery #1 if it's capable of taking a charge. That's exactly how the ACR works. Once the selected battery is charged, it starts charging the backup.
 

PondTunes

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Re: Battery Switches & Setups Demistified

Pond Tunes
You can not charge battery 2 thru the isolator the way you state. The diode for battery 1 will block any charge from going to battery 2. You could use a voltage controlled relay or a ACR and it would work.

For the isolator to work you must have the alternator to go to the common wire on the isolator. A isolator is just two diodes hooked together. The alternator connects to the junction between the two diodes. Each diode allow current in one direction only to each battery.

It does not work like you state and if it did then battery 1 would discharge to battery 2 any time battery 2 was lower than battery 1. In the case of a trolling motor on battery 2 you would end up with two dead batteries.

Sorry for being confusing boatist I only intended for a one way blockage of voltage ie a single diode setup thus the confusion. To use a off the shelf "dual battery" isolator that has a common pole the diagram would need to be modified to be connected like this:
1engiso2.jpg


As a Side Note I would never recommend this or any other dual battery charging setup on a single outboard engine powered boat. Always check your charging systems output before you decide on adding batteries.
 

Boatist

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Re: Battery Switches & Setups Demistified

Rather than engine at the top would be better to say alternator.
Then off the common at the bottom of your switch where you say house load put a branch in the red wire that says Starter or Starter Solenoid.
At that point I think would be hard some one with basic wiring skills to not under stand the wiring.
 

Bugs825

Cadet
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Re: Battery Switches & Setups Demistified

diagram.jpg


ok I got a question....

I have this setup and want to add a onboard float charger. Would this work and if so where would it go??? Is it a problem if the float charger only puts out 1.5 amps???

Thanks
Nathan
 

fishmen111

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Re: Battery Switches & Setups Demistified

Me thinks this thread needs to be retitled

Battery Switches & Setups Remystified

Cheers.....

:D I agree.
Now I see how a $400 toilet seat can be justified.:D:D:D
So if I understand ya'll correctly, Smart Tabs will fix my multiple battery probl..........................oh, forget it!

I'm with Silvertip, love my simple OFF/1/2/BOTH switch (Perko). First thing I put on every new boat.
 

drewpster

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Re: Battery Switches & Setups Demistified

My Turn My Turn,

The challenge is to keep a fresh battery no matter what. This means you must keep a fully charged battery separate from the one you use all the time. There are several ways to do this.
1) Manual switches- This system consists of a manual switch to which all your batteries are connected as well as all the loads. You may manually switch to whatever battery you want to use or to both depending on your needs. (1-2-both) These work great except you must REMEMBER to do the switching. They are best for day boaters. Charge them up at home, switch to number one, run all day until it gets weak, switch to number two to get back home. Or if you use both of them and they need some charging simply switch to both and let the engine do some charging.
2) Diode Isolators- The diode isolator works like an automatic switch to keep both batteries charged up. It also keeps the batteries disconnected from each other. This means you can connect one battery to essential systems like engine, nav lights, bilge pumps and the like and run all your toys off the other. When the toy battery gets low there is no need to remember to switch anything, simply start the engine and both batteries get charged up. The down side is that the isolator will consume a small amount of power. This means that it will take longer for the engine to charge the batteries back up. A manual switch is also normally used in the system to allow a manual override in the event of an emergency or a failure.
3) Battery combiner- A battery combiner works just like an isolator. The difference lies in the way the combiner allows both batteries to charge and how it keeps the batteries separate. Instead of using a diode, a combiner will use a mechanical switch which senses when battery charging is taking place. When it "sees" the charging current it turns the switch on and connects the batteries together. When the engine is shut down and the charging current goes away the combiner turns the switch off separating the batteries. The benefit of a combiner is that there is little or no loss of power across them. So more of the charging current reaches the batteries during a given time. A manual switch is also normally used in this system for emergency switching of the batteries.
Isolators and combiners are great because they help remove some of the human factor. When I am on the lake the last thing on my mind is what position the battery switch is in. I have forgotten mine a long way from home. That's why I now have automatic systems in both of my boats. There is nothing like the sinking feeling you get when the engine goes click instead of vroom! The point is to have a good battery at all times. So no matter if you go with an offshore system like I have in my little cruiser or if you throw an extra battery in the fishing boat, keep a charged battery on board.
 

neilk

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Re: Battery Switches & Setups Demistified

I have dual 2005 F150s Yamahas with dual batteries and 1,2,both,off switches.
Question can you damage the charging system by running with both switches in the both position. I know it's better to run with 1 switch set to each engine.

Thank you,
neil
 

dingbat

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Re: Battery Switches & Setups Demistified

As a Side Note I would never recommend this or any other dual battery charging setup on a single outboard engine powered boat. Always check your charging systems output before you decide on adding batteries.

Currently running a 2 battery setup on a single outboard. Two grp 27 deep cell batteries connected to your typical 1,2, both switches.

Running electronics off both batteries to minimize interference problems. Getting tired of playing with the switch to keep both batteries charged. 75% of the time on the troll. Troll 6-10 hours a day in season. Start to see voltage drops on secondary battery after a long day. Had pretty much decided on installing a ACR until I read this.

Alternator (35 amp) outputs exceeds total demand. Just want automated charging system

Your thoughts?
 

flargin

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Re: Battery Switches & Setups Demistified

Sorry for being confusing boatist I only intended for a one way blockage of voltage ie a single diode setup thus the confusion. To use a off the shelf "dual battery" isolator that has a common pole the diagram would need to be modified to be connected like this:
1engiso2.jpg


As a Side Note I would never recommend this or any other dual battery charging setup on a single outboard engine powered boat. Always check your charging systems output before you decide on adding batteries.

Darn great thread, yes it is very confusing to many, but that is because it is VERY confusing to understand. there are a lot of variables.

I like this model, but recommend another model, based off this model (note you can use 5 as your basis as well, though I agree it is harder for most to understand)

add a on/off switch to off-load house service from battery 2 (eliminating the To house from battery one). If you can pull this off you leave your main switch on 1 the starting battery, and all house service comes from the deep cell (bat 2), which is what most people want to have happen. You don't have to switch service during the day, and you don't have to re-set to start your battery. If your world falls apart, switch to Both, start and both systems are charging.

THanks, somehow this needs to be stickied with all this great knowledge. I think it may need a little cleanup as the path is fluid, but GREAT info. I was thinking of doing something similar, but was thinking about purpose based...

1. Single battery.
2. Dual battery, switching between starting, running, fishing/drinking & radio
3. Dual battery, switching on at launch, off at done
--- Main switches by batteries
--- electronic switching

etc. They get very complex as you ad dual motors, house batteries, etc. I would be happy to help, let me know..
 

cheesewiz

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Re: Battery Switches & Setups Demistified

Is it possible to use diagram #1 and just add an ACR between the positive terminals like I put on the diagram?
 

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bruceb58

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Re: Battery Switches & Setups Demistified

Is it possible to use diagram #1 and just add an ACR between the positive terminals like I put on the diagram?
Not a problem. That is how my boat is hooked up. You don't seperate the house from the engine but for most smaller boats where its hard to seperate the two, that is fine.
 

cheesewiz

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Re: Battery Switches & Setups Demistified

Not a problem. That is how my boat is hooked up. You don't seperate the house from the engine but for most smaller boats where its hard to seperate the two, that is fine.
Thanks, I just hooked up the switch and didn't want to get the four post switch.

I've read that the negative from the second battery should not go to the first battery, and it should go to the main grounding post to seperate the circuits. How necessary is this?
 

bruceb58

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Re: Battery Switches & Setups Demistified

Not absolutely necessary. I run each battery ground to the block but if the batteries are right next to eachother, you can just run a short ground to the adjacent battery.
 

Demonical

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Re: Battery Switches & Setups Demistified

In all the diagrams I have looked at for Isolator installation, the alternator output has to be connected to the middle terminal of the Isolator, then the #1 post of the isolator goes to the positive on the main battery, and the #2 post goes in to the positive terminal of the AUX battery.

So here's a question.

If I look at the red(Pos) and black(Neg) wires coming from my engine, to the main battery, can I assume that the RED is from the Alternator and I can locate that on the middle terminal of the isolator? The I can feed power to the positive terminal of the main battery off terminal #1 and to the positive terminal of the Aux battery, off terminal #2 of the isolator?

Or is that too simplistic?
 

jhebert

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Re: Battery Switches & Setups Demistified

"Battery Switches & Setups Demistified"

Misspelling of an important word in the title of this work impedes its acceptance as authoritative.
 

bruceb58

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Re: Battery Switches & Setups Demistified

In all the diagrams I have looked at for Isolator installation, the alternator output has to be connected to the middle terminal of the Isolator, then the #1 post of the isolator goes to the positive on the main battery, and the #2 post goes in to the positive terminal of the AUX battery.

So here's a question.

If I look at the red(Pos) and black(Neg) wires coming from my engine, to the main battery, can I assume that the RED is from the Alternator and I can locate that on the middle terminal of the isolator? The I can feed power to the positive terminal of the main battery off terminal #1 and to the positive terminal of the Aux battery, off terminal #2 of the isolator?

Or is that too simplistic?
You should really start a new thread instead of tacking on to an old one. If you use an isolator(I wouldn't) track down the wire from the alternator and remove it from its destination(usually the starter).

Instead of the isolator, go with an ACR. Its easier and a better way to go.
 

Demonical

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Re: Battery Switches & Setups Demistified

Why start a new thread when it's the topic I need info on? :confused:

As to the isolator, today I was at an RV store and I saw a battery selector switch, with isolator included. It looked to be a 'dirt simple' solution.
Friday I am going to hit Barry J's Marine in Edmonton and talk to them about this stuff. I expect I'll buy one of those kits there, but will listen before deciding.
 

bruceb58

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Re: Battery Switches & Setups Demistified

Why start a new thread when it's the topic I need info on? :confused:
because many people will read half way down and realize this is an old thread and just give up or they will read all the way down...realize its an old post and be so frustrated that they read for 20 minutes and won't bother answering your question. You will get way more answers if you post a new thread.
 

383s10tim

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Re: Battery Switches & Setups Demistified

Ok I have read through this whole thread and have a question that wasnt covered, I have a single inboard with a 3 battery setup, I have 2 dual purpose for my 1800 watt sound system and a separate dual purpose for starting.

The 2 for the sounds are on a perko switch and the 1 for starting is hooked up in the stock configuration, why is it that I cant start the boat with the switch in the off position? My starting battery isnt hooked up to the switch its hooked up as if the other 2 batteries never exsisted. I want to be able to isolate the starting battery from the other 2 so it doesnt get drained when I am anchored and so when I turn the switch off I know all the charging is going straight to the starting battery.
 
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