Concerned with dual battery readings on AR240

[subysti]

I'm starting to wonder if the readings are correct on the connext screen or there is a wiring problem somewhere. I have checked all the wiring at the batteries and have the parallel switch turned off. Both batteries started at 12.7VDC and at the end of the day both are reading 12.0VDC. It seems that there is a connection somewhere in the system between the 2 batteries that is draining both equally. I repair X-ray generators and linear accelerators for a living so I'm familiar with wiring just a tad. Does anyone have a schematic of the 2015 electrical systems?

 

[Murf'n'surf]

When you say "at the end of the day" ...does that mean after running the boat out on the water all day using the stereo etc?

If so, I would assume you have used more energy than the charging systems have replaced during your run.

 

[subysti]

I agree but the house battery should have been used more than the starting battery. The starting should basically still have a full charge as then engine were only started a couple times. The house battery should have been lower but they both read the same on the display.

 

[txav8r]

@subysti , getting a grasp of how the switch and dvsr works is good. It isn't as involved as what you work with, but if your not understanding it, it can mislead you. Batteries that are paralleled when they are not equal will level between each other. I have said a thousand times, that we don't all boat the same way. If you are starting and stopping often, every time you do, the engine charge placed on the start battery is sufficient to close the dvsr and let them combine. Enough time doing that and they will level out with each other. So as @Murf'n'surf said, if your running the stereo hard, you may be using more than you think, and draining the house battery. But the repeated starts will give opportunity to level the two batteries. Sounds pretty normal to me.

 

[subysti]

well according the manual its not working correctly. The only time the DVSR should close is when there is a voltage of 13.4VDC applied to the charging battery then after a 5 second delay it will combine the batteries for charging. Anything below 12.8VDC and the DVSR should disengage. So while just anchored and listening to the stereo the house battery voltage should drop but not the starting battery, but they always seem to drain equally. Just with our engines running they don't put out 13.4VDC they need to be around 4500RPM to get this voltage out from the stators. there is an option for a remote charging LED that shows when the DVSR is closed to combine the batteries that I think I'm going to install. I'm also going to attach my DVM to the batteries to see if what the display shows is actually what is happening on each battery. When we were out yesterday, we launched the boat and drove 10 miles and anchored, hung out and listened to the stereo for a few hours and headed back. I cant see how the starting battery would drop from 13.5 V to 11.9 by the time we got back to the dock when the only time they should be combined is when there was a charge voltage over 13V applied. BTW my stereo is just the 4 cabin speakers and a wet sounds HT-6 amp, nothing crazy.

 

[txav8r]

@sysinu , the batteries combine when your cruising that 10 miles to and from anchorage. It isn't totlalky linear. While 4500 rpms may be the engine speed that turns the magneto fast enough to produce charging voltage, it may produce it lower or even higher. Also, the Dvsr has set limits but they too are not exact. The hard part for some to understand, is that the charge isn't selective. Some say it charges the start battery first. This isn't true, it charges the lowest battery first. And your charging system can't produce as much as a fully charged battery can produce. So the fuller starting battery can literally dump its load into the lower house battery because it is the bigger flow than the charging system. All of that said, doesn't mean you don't have an issue sonewhere, but batteries will level in the scenario you described. How big are your batteries? Stock in every way? Condition? Do you keep them on a smart dual charger when but in use? What charger? Have you checked the electrolyte levels?

 

[subysti]

Batteries are brand new. First time out on the boat. I have a pro mariner gen 3 dual bank smart charger connected when not in use. That's something I need to get used to doing. Never used a charger on my I/O except during off season.

 

[OperationROL]

This was the same issue I reported in another thread. Mine behave exactly as you described. I am going to do some more investigating when I get the boat out again. Unfortunately, I have no idea when that will be.

 

[MikeyL]

I agree but the house battery should have been used more than the starting battery. The starting should basically still have a full charge as then engine were only started a couple times. The house battery should have been lower but they both read the same on the display.

@subysti ......... Excellent question .......... However here is my take:
I also keep my brand-new Interstate batteries on a Minn-Kota on-board VERY Smart Charger, as long as the boat is on the lift.
When we are out on a ride or cruise, we do stop and start a few times.
We play our music (Audio amps not yet connected up).
I DO have the SAME results as you do.
I would no longer be concerned whatsoever about this. Personally, I think you're fine.
Well, I don't know if you're "Fine" or not, (kidding) but I do not feel you have a worry here.
Best Wishes, Mikey Lulejian

 

[MrMoose]

I hope that Yamaha is paying attention to subysti's observations and MikeyL's confirmation, because MAYBE that's not how Yamaha intended the system to perform. Maybe it would be a good idea if subysti contacted Yamaha directly with his observations and shared any reply that he gets with the forum.

 

[MikeyL]

I hope that Yamaha is paying attention to subysti's observations and MikeyL's confirmation, because MAYBE that's not how Yamaha intended the system to perform. Maybe it would be a good idea if subysti contacted Yamaha directly with his observations and shared any reply that he gets with the forum.

Please help me as now I am confused. You leave the dock with 2 charged batteries.
You are running the engines which are also CHARGING the already fully-charged batteries.
The CONNEXT System says they both have the same voltage.
This makes sense to me. I am sure now I do not understand something.
What am I missing ?

 

[subysti]

Ok today we left the dock with both batteries charged. When anchored and listening to music both batteries display that they are both draining it seems. When we left the place where we were anchored both batteries displayed 12.1 volts. I ordered the yamaha service manuals to try and trace the connection. I'm thinking the connext system might be linking the batteries somehow.

 

[MikeyL]

How many of the battery switches do you have turned to "ON" ?

 

[subysti]

Just the house and start battery. Emergency parallel is off.

 

[MikeyL]

OK> I still think you are fine.
You most likely have deep-cycle marine batteries.
The audio system (stock) does not draw very much current at all.
I'ld simply wait and see how it develops. I feel you are fine.

 

[subysti]

Actually the dealer installed 2 marine starting batteries. Go I going to swap the house battery for an optima blue top deep cycle marine. I still don't think they should be draining at the same rate though.

 

[Murf'n'surf]

I think your assumption of the Connext linking the two batteries is correct.

You should be able to do a simple continuity test to prove this.

 

[MikeyL]

To me there is a simple and inexpensive test.
Do whatever you wish with your boat.
WHEN you are ready, stop the boat, turn both battery switches off, and use a $ 15 digital voltmeter from Harbor Freight, Home Depot, etc and MEASURE what you have.
See if your meter agrees with your Connect.
Then you'll know for sure.

AND: You'll have substantive facts to discuss with Yamaha, if necessary.
Good Luck, Mikey Lulejian - Lake Oconee, GA

 

[subysti]

That's exactly what I'm going to do tomorrow. Charging the batteries tonight and testing tomorrow.

 

[Murf'n'surf]

I'm betting the Yamaha engineers already know where a diode needs to be wired in to stop the circuit from completing.