charging 2nd battery question

w&w

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New to this forum, hope I am not not violating any protocols, yet. We are enjoying our new 2020 208 Adventure and needless to say, feeling a little overwhelmed being a life long small boat sailor. My power boat experience (besides being a guest) is back in the 60's with a 13 ft Whaler. Please have pity ;)

Anyway, I am not clear if battery 2 is being charged while the switch is on 1 (and visa versa).

If both batteries are not being charged while the switch is on a single battery, what is the proper procedure to charge a battery that has been drawn down by use at mooring (let's say not enough juice in that one to start engine)

Being new to this all, I am not sure what electrics the boat came with. The switch (if that matters) is a Blue Sea Systems 6007

And if this has been discussed before, please point me to the appropriate thread.

thanks
-w
 

wspitler

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Normally only the selected battery gets charged. However, if you have a newer Yamaha, there is an isolator cable you can add that will charge another (unselected) battery as the alternator, through the voltage regulator, has that capability. Highly recommended.
YAMAHA 68F-81949-01
 
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DennisG01

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Generally speaking, whatever # the switch is on... is the battery being used and charged when the engine is running. HOWEVER, your engine may have an aux charging wire in which case both batteries are always being charged (older Yamahas have this, too). I can't tell you if it does/does not have that - that's something you have to physically verify. You might call your dealer and just ask them, if you're not sure what you're looking at.

On a mooring... Your bilge pump should be wired with a float switch, making it an automatic bilge pump. And, the float switch should be wired directly to one of the batteries - which means you can turn the battery switch to OFF and the bilge pump will still work.
 
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wspitler

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You can start the engine on one of the batteries and switch while it is running to charge the weaker one, but a word of caution. Never go thru "off" on the battery switch with the engine running as it can damage the charging system.. Always turn the switch thru the 1+2 position to go from #1 to #2, never thru off.
 
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w&w

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Thank you all.

I will ask the dealer about the isolator cable.

And if not, I now know the correct proceedure to switch to the "weaker" battery. I was curious about that.

And, BTW, it has been made clear to me by the dealer that the bilge pump bypasses the switch.
 
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Bloodweiser

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Or you can instal a blue seas automatic charging relay and not worry about it .
 

seasick

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On my 208, I select one battery and alternate which one randomly (or by the date, even date battery 2, odd date battery 1)
I run on that battery most of the outing but may switch to BOTH for the trip back to the dock assuming it it takes longer than 15 minutes or so. That helps top off both batteries.
There are good reasons to start and run on one battery: By starting on one battery you are in effect testing it. If it is dead or weak, you will know. If you start on BOTH, you may not know that you have one or two weak batteries.
When running on two batteries, if you run them down as might happen when anchored and enjoying the music or whatever, you will be dead in the water. Running on one leaves the other charged battery available in a pinch
With respect to an ACR or other type of charge isolater , they are nifty devices but if run on BOTH, you can still run down BOTH.
When BOTH is selected but you are not running the motor, it is possible for one battery to be discharged by the other for various reasons.( different battery conditions and/or characteristics.

Note also that if you can not start your motor unless you select BOTH, something is amiss and needs to be fixed.
 

SkunkBoat

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For the life of me I don't understand why they would sell a boat with 2 batteries and not hook up the AUX charging wire. The circuit is in the motor just for that reason.

I just got new Suzukis and I had to request the charging cables. They sounded like nobody ever asked for that before. You think they would suggest it....since most people don't even know its an option.

I have 4 batteries. Each motor charges its own starting battery and both motors charge the House with the Aux cables. All of my batteries are always charging.
 
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ScottyCee

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Mostly they all are always fine, and that's how I treat them too.

My new boat with twin F225 is the first one that in a dead battery situation I won't be able to pull out the starter rope and be fired up in 30 seconds. That leaves me with an uneasly feeling...
 

SkunkBoat

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I always ran on 1+2. Load shared, both charging...

The only time you should run in "Both" is when you have a problem and can't start with a single battery.

If you have a weak or dead battery and you put it in BOTH the bad battery will run donw your good battery.
 
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