Batteries die on the water

[Richey rich]

So I have a ll new batteries this year and I stay plugged in all week
At the Dock. I go out on the lake maybe once a week , normally just For a short ride. This weekend I started the boat ,went for an hour ride, stopped and had lunch for about 2 hours and when I came back my motors would not turn over. I had to use the emergency start to get them going. I came back to the dock and plugged in over night , then took the batteries to west marine and had them tested. They all test 100% and had a 100% health rating. What could my problem be?​

 

[Fred]

Since your boat has at least 4 batteries in sets of two each for port and starboard, are the two new batteries being used as a pair?

 

[Richey rich]

There are 4 batteries running in sets of 2. All 4 batteries are brand new.

Since your boat has at least 4 batteries in sets of two each for port and starboard, are the two new batteries being used as a pair?

 

[ZZ13]

Might have a dead alternator. Both sides dead after a run or only one bank? What do the volt meters read when underway?

 

[Mike Blake]

There are 4 batteries running in sets of 2. All 4 batteries are brand new.

New is not necessarily good.!! Ask me!

 

[Fred]

Well New fully charged batteries should easily start your boat after two hours at anchor. Perhaps you have a marginal ground connection.
I would monitor the amp draw at anchor and the charging voltages when running as well as when plugged in at the dock.
It is possible to for a battery to test OK and still be bad but you could not start either engine without using the emergency start.

 

[Richey rich]

So it seems that normally it was just might port side that I had the problem with, but this last time port and starboard would not start. Normally when I'm under way my voltage is running at about 14

Might have a dead alternator. Both sides dead after a run or only one bank? What do the volt meters read when underway?

 

[Richey rich]

I agree, that is why I took them to be tested. But all test show that the batteries are good

New is not necessarily good.!! Ask me!

 

[Richey rich]

I wish the batteries were ran so that two of them were for starting the motors and two of them were running the house. That way you could just turn off the two batteries to the engine and still run all of your electrical, without having to worry about starting the motors after running your stereo and lights for a couple hours at Anchor.

Well New fully charged batteries should easily start your boat after two hours at anchor. Perhaps you have a marginal ground connection.
I would monitor the amp draw at anchor and the charging voltages when running as well as when plugged in at the dock.
It is possible to for a battery to test OK and still be bad but you could not start either engine without using the emergency start.

 

[Steve Craig]

Get a DC voltmeter across the battery terminals next time you have the engines running. You should see about 13.6V at idle, up to 14.2V at higher RPM.
Anything less than about 12.8V, you'll need to diagnose charging system issues.

 

[Richey rich]

Thanks, I'll be out on Tuesday and I will do that. I'm also going to check the ground and the alternators.

Get a DC voltmeter across the battery terminals next time you have the engines running. You should see about 13.6V at idle, up to 14.2V at higher RPM.
Anything less than about 12.8V, you'll need to diagnose charging system issues.

 

[Bt Doctur]

He may not even have separate charging systems either. That class of boat should have a generator
He needs to find out what works and what dosent work on each battery.Then have the battery cables and battery switches rewired to have dedicated engine starting batteries and nothing else.
Anything else goes to house battery system

 

[Mike Blake]

I just went through this with my 3 optimas. One drew tested to 9V one tested to 11, and the third was 12V. So I just went and got 3 new ones. Problem solved. I thought I had a bad port starter but was the battery. Always test the batteries first!

 

[JimT]

So I have a ll new batteries this year and I stay plugged in all week
At the Dock. I go out on the lake maybe once a week , normally just For a short ride. This weekend I started the boat ,went for an hour ride, stopped and had lunch for about 2 hours and when I came back my motors would not turn over. I had to use the emergency start to get them going. I came back to the dock and plugged in over night , then took the batteries to west marine and had them tested. They all test 100% and had a 100% health rating. What could my problem be?​

If all of the batteries were dead I don't see how the emergency start would work.

 

[Richey rich]

The the emergency start parelals two batteries for a combined cranking power. One battery did not have enough juice to start but when you parelal two batteries (emergency start) it had enough(barely) to get them going.

If all of the batteries were dead I don't see how the emergency start would work.

 

[Richey rich]

UPDATE....
so i took all the batteries in to west marine and they all tested good, so i let them sit unconnected to see if the would lose a charge. After 3 days i tested them and none of them lost juice. I took them back out to the boat hooked them all up disconected from shore power as if i was on the lake and turned on all my cabin lights on and ran my stereo for almost 4 hours while i was relaxing. once an hour i would start the boat and just let it run for a few minutes then shut back down. Basicly i was TRYING to kill my batteries. I left that night and went back the next evening(still not plugged in and just running a few accessories, and low and behold the damn thing starts right up. Go figure! maybe i just had a loose battery connection. Oh well, for now i will call it FIXED.

 

[Dawn Norakas]

Well, I was hoping you were going to solve my problem. We have 7 blue top optima batts. 5 of which are new this year 2 new last year. We are having the same issue. We too found a loose connection and thought problem solved....NOPE! We had the 2 older batts tested, they tested fine. So my next thoughts are, batt isolator, or battery charger. The week we found the loose connection she wouldn't start in our slip after sitting on shore all week. We are getting 14v when under power. My next move is to put an ohm meter on the isolator to see what it's putting out. We have a 3 bank 49amp battery charger. Maybe it just got tired and gave up.

Thoughts?
Dawn
1998 400 Sea Ray DA
Lake Texoma, Texas

 

[Island Express]

any thoughts on rewiring to have 2 house batteries and one for each engine? I want to put all stereo equip on the house batts and leave starting batts alone.
I think I have a cable problem that joins the batteries together on one side. they just don't last very long and wont start the starboard eng unless run the port to charge.
thoughts?