Dual Use vs. Starting Battery

[TurboDan]

As most of you know, I bought a new (well, to me!) boat last October.  Before I bought it, the previous owner purchased a brand new starting battery, since the old one had not been replaced in a while. 

Going into next year, I'm wondering about the battery situation.  I don't have a lot of electronics on board - just basic GPS, VHF and fish finder.  All monochrome displays, no LCD or anything like that.  However, I plan on doing some night boating next year, both for weakfish and to occasionally view the fireworks at the Manasquan Inlet.  So, I'm wondering if a "dual use" battery would be better.  How long before a starting battery loses its juice with, let's say, the VHF on and the lights on?  An even more common situation would be simply the VHF and fishfinder on, for daytime boating.

Any advice would be appreciated.
Dan

[Luna Sea 5]

im my opinion, 2 batteries are a must and they will charge each other when both are used at the same time. 

[SouthPaw]

Yes if at all possible mount the second battery with selector switches. And a jumper battery should be a must, I consider it as part of my safety equipment. Also make sure it's tested or charged at least once a month. Thats the ususal recommendation.

[mboy]

This is what you want and no need to mess with switches (which you have to remember to set properly each time or they are worthless.

http://www.yandina.com/c100Info.htm

My boat also has 1 starting battery and this is what I am doing this year.

Adding the yandina combiner.

The starting battery will ONLY be connected to the starter and the combiner. This battery will do NOTHING other then start the engine.

The 2nd battery will also be connected to the combiner and all the house loads (all the fuse panels/circuit breakers on the boat that crun all the electronics, lights, etc.

The combiner COMBINES the batteries when the engine is running (alternator charging) OR it senses a charge from a battery charger (onboard, external, etc). This allows BOTH batteries to be charged at once (keep in mind, both batteries will charge when you are idling, running, etc).

When the bengine is off or it sense no charge from a battery charger, the batteries are completely independent of each other. Your electronics, lights, etc will run off the deep cycle battery. NOTHING will draw down your starting battery since it is ONLY connected to the engine starter.  As long as the battery is healthy it will NEVER be drawn down.

If you run down the dual battery and your lights, electronics go out, just start the engine and run for a bit to charge it up. The starting battery will be FUllY charged.

There is a seperate lead from the combiner that can be hooked up to a switch that will manually combine the batteries when there is no charge so you can jump one to the other just in case your starting battery is going abck and not holding a full charge.

With the combiner, you can also use bon/off or 1/2 all switches, but there really is NO need to.

1/2/off/both switches are OLD SCHOOL.

Much better alternatives out there now a days.

Combiner does all the work for you. No needing to remember to switch from 1 to 2 to charge, etc.

Yandina has lifetime warranty and is only $50.

This is EXACTLY how I plan to add another battery (deep cycle) to my existing starting battery.

Switches are a waste of time and a thing of the past as far as I am concerned.

Ask my pops what happens when you forget to switch to the other battery , leave switch on both and run them down.

You now have no battery to strat the engine with.

Almost impossible to do with a combiner!

[mboy]

im my opinion, 2 batteries are a must and they will charge each other when both are used at the same time. 

That is not really correct. They will draw off each other when connected if one is bad, it will kill the ter battery.

When both are combined and the engine is running, it will charge both since they will be wired in aprallel.

Forget to switch them back to 1 or 2 while engine is off and you running a lot of stuff, you just killed both batteries and now you don't have 1 to start your engine.

[rugman]

this is why I allways install a ele bow motor , this way I have another batt in the boat and a way to get back just in case . might be alittle slow but I will get back , being on alot of lakes and running out of gas

[Luna Sea 5]

I have 1 battery that starts the engines, and the other runs the electronics.  I can run each one separate, or together to charge each other.  Both batteries each have a 1/2/all/off switch on it. 

[mboy]

And if you leave the switch on all (which combines both batteries) and you run them down, you do not have a battery to start the motors.

Say you leave it on all when you start the engines before your trip out. Then you forget to change it back to 1 or 2 and you leave the radio on too long, etc or whatever, you don't have a battery to start your engines because you killed both of them.

By leaving it on both, the batteries aren't "charging" each other, their is no such thing. They are pooled together and will both be drawn down.

The only thing that charges your batteries are a running alternator or a battery charger. 
When you jump 2 batteries, you are connecting them in parallel.
You are taking stored electricity from the stronger battery and applying it to the weaker battery. This of course, draws down the stronger battery.

The combiner takes all the work out of it.

Combines them automatically to charge when there is a charge source. When that charge source goes away, the batteries are seperated from one another.

Kill the house battery and the starting is still fully charged.

Start the engine and both batteries charge.

Why would you want a manual switch that has to constantly be in the correct position, when for $50, you have a reliable device that does it for you?


Nick, not only is your setup (which cam e from the factory I am sure) is 5xs more expensive to implement, it is 100xs more work to deal with.
$50 combiner, install it with battery and never have to think about it again.

Period!

[Luna Sea 5]

the way they set mine up is confusing, I will show you this season.  Usually you have 2 batteries with 1 switch.. I have 2 switches.  If I have them set correctly, one battery starts 1 of the engines of the boat, the other works the electronics and the second engine.  If I forget the electronics on and kill the battery, I only kill 1 battery and not both, so I always have a one battery back up.  If I was to put both sets of switchs on ALL, they both will charge together with the alternator, when the engine is running.  If I put the first set of switch on ALL, I still won't be able to access the second battery unless I put that switch on battery 1. 

Remember, its like nothing I ever seen before, so I am sure you can use the basic rule that your stating, out of the question. 

[mboy]

Too confusing.

For Turbo Dan (and myself) the Yandina combiner is the way to go. Cheapest, easiest and most reliable solution.
He can always add an on/off switch between battery(s) and the house circuits if he wants ( I am not going to bother).

Just one more thing to get in the way.

[Luna Sea 5]

If I have them set correctly, one battery starts 1 of the engines of the boat, the other works the electronics and the second engine.  If I forget the electronics on and kill the battery, I only kill 1 battery and not both, so I always have a one battery back up.

With this said.  Lets say I leave the electronic on.  I will be killing 1 battery and obviously 1 engine will not start because of it.  At that point, I start the other engine.  Once that engine is started and runs for a while, that alternator will charge my dead battery which operates my other engine, hence, I will get the other engine started.  The battery can't charge if the engine isn't running.  Thats why they set mine up where 1 battery is strictly for 1 engine and nothing else, hence there should be nothing to kill that battery, even if I leave all my lights one, pumps, wells, everything... nothing will kill that battery.  I think the set up is confusing, but very safe.

[mboy]

If it works as you say, then it is a viable setup.
However, those switches are easily 50 each + another $30-50 fr all the extra wire to connect 2 switches to the 2 batteries (and each other) and you still have to play around with switching them.

TruboDan spends $50 (+ $5-10 on a negative lead to connect both batteries - together) on the combiner and never thinks about it again.

[Luna Sea 5]

Mike, I agree with you. Remember, mine was done from the dealer and you know as well as I, they never like making things easy for the customer.

Mine was defiantly done in a sophisticated level, a level that I am sure I would never need it to be.  With that said, if I had to do it from scratch, I wouldn't do it that way. I just thought I would share the way mine was done, and if others like it, then they can do it that way.  Me personally, I wouldn't go through the headache.

[TurboDan]

Too confusing.

For Turbo Dan (and myself) the Yandina combiner is the way to go. Cheapest, easiest and most reliable solution.
He can always add an on/off switch between battery(s) and the house circuits if he wants ( I am not going to bother).

Just one more thing to get in the way.

Sounds like that could be the way to go.  Only problem is that there's only space for one battery in my boat.  The battery's in one of the stern consoles, next to the oil canister.  Can you have one battery back there and one, say, in the center console?

[Luna Sea 5]

Too confusing.

For Turbo Dan (and myself) the Yandina combiner is the way to go. Cheapest, easiest and most reliable solution.
He can always add an on/off switch between battery(s) and the house circuits if he wants ( I am not going to bother).

Just one more thing to get in the way.

Sounds like that could be the way to go.  Only problem is that there's only space for one battery in my boat.  The battery's in one of the stern consoles, next to the oil canister.  Can you have one battery back there and one, say, in the center console?

you can, but further they are from each other, more wire you have to run, and also bring the price up a bit.

[SouthPaw]

the way they set mine up is confusing, I will show you this season.  Usually you have 2 batteries with 1 switch.. I have 2 switches.  If I have them set correctly, one battery starts 1 of the engines of the boat, the other works the electronics and the second engine.  If I forget the electronics on and kill the battery, I only kill 1 battery and not both, so I always have a one battery back up.  If I was to put both sets of switchs on ALL, they both will charge together with the alternator, when the engine is running.  If I put the first set of switch on ALL, I still won't be able to access the second battery unless I put that switch on battery 1. 

Remember, its like nothing I ever seen before, so I am sure you can use the basic rule that your stating, out of the question. 

I think my boat is set up the same way as your,LS3. I get confused with were I should put the switches. I usually leave them on both, Which I know drains both the batteries when the engines aren't running. That is why I carry a jumper pack all the time. How ever Mike, I looked at the wiring diagram for a dual engine/ dual battery setup with the combiner and they show several switches in the system. This is confusing to me. How does this work?

[mboy]

You sure can. The combiner comes with 25' leads I believe. You can not shorten them, but you can lengthen them if you want (you wouldn't have to).
I would def keep my starting battery where it is now and get yourself a deep cycle, place in cabin/helm and conect your fuse block/circuit breaker panel to that.

You will need to tie both batteries grounds together with a black cable, the attach 1 read from combiner to each of the batteries +. That's it!

[mboy]

the way they set mine up is confusing, I will show you this season.  Usually you have 2 batteries with 1 switch.. I have 2 switches.  If I have them set correctly, one battery starts 1 of the engines of the boat, the other works the electronics and the second engine.  If I forget the electronics on and kill the battery, I only kill 1 battery and not both, so I always have a one battery back up.  If I was to put both sets of switches on ALL, they both will charge together with the alternator, when the engine is running.  If I put the first set of switch on ALL, I still won't be able to access the second battery unless I put that switch on battery 1. 

Remember, its like nothing I ever seen before, so I am sure you can use the basic rule that your stating, out of the question. 

I think my boat is set up the same way as your,LS3. I get confused with were I should put the switches. I usually leave them on both, Which I know drains both the batteries when the engines aren't running. That is why I carry a jumper pack all the time. How ever Mike, I looked at the wiring diagram for a dual engine/ dual battery setup with the combiner and they show several switches in the system. This is confusing to me. How does this work?

Depends on how your switches are set up. My father has the 2 batteries 1 switch setup and I am helping him add the combiner this year.

Here is the setup without switches (exactly what I am doing except they show trolling motor here. Pretend trolling motor = fuse panel:

[mboy]

In the setup here:
http://www.yandina.com/acrobats/C100Data.pdf

You would connect the house panel to terminal 2 on the switch and starter to # 1.  You would always leave the switch on # 1 (both batteries will get charged via combiner no matter what and the house panel will run off of 2 without having to be switched on #2). If for some reason you starting battery dies (which should neve happen if battery and engine are healthy), you can switch to both to give your starting battery a jump).

That is how I will connect my father's this year since he already has a switch.

if starting from scratch (which I am), I do not want or need the switch.

Dan COULD add an on/off switch between the house panel + and the battery positive if he wanted to make sure the house panel is disconnected from the battery while away from the boat, but there is NO need in my opinion (and I am opting not for my setup).

This combiner REALLY takes all the work out of dual battery setups.

Really slick, even if you have an existing switch, just have to do a bit of rewiring (easy).

[SouthPaw]

What about the second engine? Look at the schematic for dual engines one starting battery under the combiner 150. It confuses the sh*t out of me.