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Dual Battery Use Question

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Four R's

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Just picked up our boat today (2012 leftover 2275 GCW). I had the dealer install a dual battery with a switch. During the demo ride, the guy told me to start the motor with both batteries and to run it on 2 batteries until I reach my destination. Then, if I want to use the radio while anchored, I should switch it to one battery. On the trip back, he suggested going back to both batteries? I was always under the impression that I should use just one battery but to change to the other one each successive time? His reason was that it keeps both batteries charged? What say you?
 
He is giving good advice. Also never switch the engine starting battery off while the engine is running. Lots of bad things will happen. When running you want to be at 1+2 position to charge both batteries. There are automatic controllers that do it but this is a cheap effective way to handle it. We have two batteries and most of the time i leave it on 1+2. We only have the radio on and usually at low volume while floating. If i was going to blast the music for a long time i would switch to 2 only. When done for the day I will switch to off just to be safe. You will lose the radio presets but we can only get one country station on the water so it is no big deal.
 
Two batteries are usually needed only when you're running a big sound system with sub woofers and numerous energy sucking amps. Or if your boat is equipped with the power steering assist with the SeaStar.

If you're just talking about running the standard OEM sound system, they don't use very much power at all. Switching back and forth between batteries after sitting around an hour or two is not really required.

Most people don't need two switched batteries, but they're nice to have when needed. I just carry a set of jumper cables, as we are just about always in sight of other boaters in the area.
 
Mine is equipped with 3 batteries. One dedicated to running the refrigerator that is connected to shore power. The I have two AGM batteries for the motor and all other accessories. My dealer told me the AGM's only charge when the motor is running, and that when running the motor have the switch set to charge both AGM's. When floating and listening to tunes, running lighting, etc switch to battery one and keep battery two for starting the motor when it comes time to fire up the motor.

I would have thought that shore power would have charged all 3 batteries, but the dealer claims no. Does anyone here disagree with that position?
 
Four Rs - I have this:

http://www.amazon.co... charging relay

It does exactly what your dealer says you should do in your post, only it does all the switching automatically. When the motor runs, it connects the batteries together (after a short time delay) so they both charge. When you shut the motor off, it disconnects the two batteries from each other (I think there's a short time delay on this as well). Each battery still works, but one will ONLY start the motor, and the other will ONLY run the house electronics. It's really, really nice to have. Foolproof.

You can add a switch to the charging relay to turn off the batteries at night if you want, but I just have the charging relay with no switches. For the way I use the boat, I don't see a need to have a switch buried somewhere where it's hard to get at, or cut a hole in a lounger to make it easy to get at.
 
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Manitowish1 said:
Mine is equipped with 3 batteries. One dedicated to running the refrigerator that is connected to shore power. The I have two AGM batteries for the motor and all other accessories. My dealer told me the AGM's only charge when the motor is running, and that when running the motor have the switch set to charge both AGM's. When floating and listening to tunes, running lighting, etc switch to battery one and keep battery two for starting the motor when it comes time to fire up the motor.

I would have thought that shore power would have charged all 3 batteries, but the dealer claims no. Does anyone here disagree with that position?
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It is possible to wire it either way, so I think it just depends how yours are set up. There may be a standard, or typical, way this is done from the factory, and someone else will have to comment on that.

I would think you'd have to have a pretty big charger to charge all 3 batteries...
 
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kaydano said:
Four Rs - I have this:

http://www.amazon.co... charging relay

It does exactly what your dealer says you should do in your post, only it does all the switching automatically. When the motor runs, it connects the batteries together (after a short time delay) so they both charge. When you shut the motor off, it disconnects the two batteries from each other (I think there's a short time delay on this as well). Each battery still works, but one will ONLY start the motor, and the other will ONLY run the house electronics. It's really, really nice to have. Foolproof.

You can add a switch to the charging relay to turn off the batteries at night if you want, but I just have the charging relay with no switches. For the way I use the boat, I don't see a need to have a switch buried somewhere where it's hard to get at, or cut a hole in a lounger to make it easy to get at.
Click to expand...
Kaydano,

How easy, or difficult was this to install?
 
Not terribly bad. You will have to drill some holes in your boat... :)

If you have some basic DC wiring knowledge, and are half handy, you can do this yourself. I didn't find it hard.

You will need to buy some heavy battery cables and fuse holders to hook it all up safely. The instructions that come with it are good. I think you can download them off the Blue Sea website. I have to go, or I'd go find the link. Maybe later.
 
With all the things available for your battery systems, I would never go through the pita of switching batteries back and forth. Steve
 
Manitowish1 said:
Mine is equipped with 3 batteries. One dedicated to running the refrigerator that is connected to shore power. The I have two AGM batteries for the motor and all other accessories. My dealer told me the AGM's only charge when the motor is running, and that when running the motor have the switch set to charge both AGM's. When floating and listening to tunes, running lighting, etc switch to battery one and keep battery two for starting the motor when it comes time to fire up the motor.

I would have thought that shore power would have charged all 3 batteries, but the dealer claims no. Does anyone here disagree with that position?
Click to expand...
You can easily have shore power do all three, I started looking into this for mine (only a 2 bank system ). Here is the one Gerry has in his pics

http://www.dualpro.c...ucts/sportsman/

It looks pretty good.

I also had found one at Cabela's and bass pro shop. They're pretty easy to come by, just look for one that has 3 banks for charging and your good to go. A lot of them you can even tell the charger what type of battery is on that bank so it charges correctly (agm,flooded etc)
 
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Well thanks to all for your insight. It appears that the information that I received from the dealer was correct and I will follow his suggestions.
 
SEMPERFI8387 said:
I was just looking at that as Bass Pro on Saturday, and wondered if ot was a decent set up ..... guess so if your dealer used it. Might have to pick it up next time I'm there.
Click to expand...
How much was it at Bass Pro Devil?
 
Four R said:
Well thanks to all for your insight. It appears that the information that I received from the dealer was correct and I will follow his suggestions.
Click to expand...
Yes, your Dealer gave you good info, and you can operate that way however, with less than $80 and 15 minutes of work you can add an automatic charging relay as mentioned by others above. Here's how it would connect up:

cobiner_zps5bfcff52.jpg


This shows the Yandina C100 which would connect directly to your Dealer installed switch and have one wire connecting to ground. The only other change needed is to move the house wiring ( shown above as DC Panel, yours is currently connected to common along with the outboard motor wiring) to terminal 2. No holes to drill, just one or two screws to mount the Yandina to the deck. That's it! Just leave the switch set to Battery 1, and you have separate House and Battery connections, run accessories on the hook as long as you like secure in the knowledge that you have a fully charged battery available for starting. The only time you need touch the switch would be to turn off the batteries for storage, or in the unlikely event that your starting battery failed, to switch to Battery 2 to start your engine.
 
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kaydano said:
Four Rs - I have this:

http://www.amazon.co... charging relay

It does exactly what your dealer says you should do in your post, only it does all the switching automatically. When the motor runs, it connects the batteries together (after a short time delay) so they both charge. When you shut the motor off, it disconnects the two batteries from each other (I think there's a short time delay on this as well). Each battery still works, but one will ONLY start the motor, and the other will ONLY run the house electronics. It's really, really nice to have. Foolproof.

You can add a switch to the charging relay to turn off the batteries at night if you want, but I just have the charging relay with no switches. For the way I use the boat, I don't see a need to have a switch buried somewhere where it's hard to get at, or cut a hole in a lounger to make it easy to get at.
Click to expand...
My set up comes with a switch that offers battery #1, battery#2, both 1 and 2 and off. Based on what you wrote, there's no need for me to switch anything? I should leave it on 1 and 2 and never turn it off? Does the same battery always start it automatically? Why would I have the different options if everything happens automatically.Thanks,.
 
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Four R said:
My set up comes with a switch that offers battery #1, battery#2, both 1 and 2 and off. Based on what you wrote, there's no need for me to switch anything? I should leave it on 1 and 2 and never turn it off? Does the same battery always start it automatically? Why would I have the different options if everything happens automatically.

Thanks,.
Click to expand...
What Jim_R showed is adding an automatic switch to the manual setup. With it you leave the switch on 1 and the switch handles isolating the house battery with motor off and charging both batteries when running. i have the same manual switch as you. When I get in the boat I turn the switch to 1-2, this gives me both batteries for starting and both batteries charge when running. Downside is that when you sit and play the tunes you are discharging both batteries. If you have a big stereo setup you would want to switch to 2 to save your starting battery. Jim_r switch handles it without you touching the manual switch. We only have the stock stereo and never play it loud so I leave both batteries on all the time.
 
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I'm also new to all this...I have a new Benny with a dual battery set-up. Let's just say that while I was cleaning the boat, I had the radio on a bit too long and killed the battery. How do I know which is the starting battery? I have a battery tenner, but not sure which battery to begin with? Thanks for any assistance.
 
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