Battery overcharging - The Hull Truth

Joe W · 07-24-2002, 03:30 PM

I have a dual battery setup. One battery charges normal at 13 to 14.5 volts. The other battery charges at 16 to 17 volts. I'm not sure what this means. Does this battery have to be replaced.I am measuring the voltage from my Garmin fishfinder (digtal) and the analog voltmeter on the boat.

Any advice is appreciated.

Joe

Tyee 2 · 07-24-2002, 04:31 PM

I'm interested in a reply to you're question as well Joe. Before an outing last weekend I tested both battery voltages with my portable digi voltmeter. 12.81v on starting batt( full charge?)
Once on water running, dash guage read 16+ volts?
I'm used to seeing the same as you.( 13.5-14v ).

Gil Morgan · 07-24-2002, 05:05 PM

Sounds more like you have an open circuit from the engine charge circuit to the battery. Are you sure your Bat switch is OK? How about with the bat switch set on ALL, what voltage do you read?? While the dash-guage is reading the 16v plus, put your voltmeter across the actual Bat terminals and see what voltage you have there. If you read that voltage at the battery, it is either very fully charged or No Good. Unusual for a battery to go bad that way unless the battery water in one or more cells is currently missing or was missing in the past and refilled.

Joe W · 07-25-2002, 07:59 AM

Gil,

Thanks for the reply, I did not get a chance to really check this out. I plan to check all the cells and do a voltage check at each battery. I do suspect that the battery will need to be replaced.

Thanks

Thom · 07-25-2002, 09:26 AM

Since when did bad batterys start putting out more volts than good ones? Rethink your dicision to automatically replace the battery.

Thom

"I command thee, O fish of the ocean, rise to my bait"

usual suspects · 07-29-2002, 02:02 PM

mine do the same,but only underway(full speed),at idle all is normal.

sevenx · 07-29-2002, 05:30 PM

Maybe a bad voltage regulator on on of your motors if you're running twins otherwise who knows?

sevenx

Bruce Braunstein CCP
sevenx@bellsouth.net

Mumblerone · 08-01-2002, 06:52 AM

Quite an interesting problem...I'll bet it's the gage that's now broke. I have twin 175 Evinrude Ocean Pros (1996)...the port gage showed a 18 plus volts till it broke (actually it would never zeroed, even when off...stayed at about 11.0 volts). Then the starboard did the same thing. I replaced both this spring...no problem. I still wonder what caused this. Over voltage from? I like to hear a good reason. [img]/infopop/emoticons/icon_frown.gif[/img]

Gil Morgan · 08-01-2002, 10:17 AM

Mumblerone, that vintage OMC guage was the pits and I am surprised they lasted as long as they did. Be happy with your new guages.

Mumblerone · 08-01-2002, 03:48 PM

Gil Morgan - nice to hear. Thought I originally had an electrical problem. The new ones are Teleflex and believe it not ...'Fog Free'. I can't imagine why all gauges are not. Makes me want to replace them all. I'll just wait till they all break. [img]/infopop/emoticons/icon_rolleyes.gif[/img]

Montauk Joe · 08-01-2002, 05:12 PM

If you can verify that one battery is taking 16 to 17 volts, it might be bad and have a high resistance to charge. Take the voltage after it has been left alone for a while (overnight) and see if it 12 volts or less. If so, then it is not charging or talking a charge. If you have a single motor, then I would not think it was a voltage regulator problem, if dual then maybe. You can "cook" a battery if the charge is too high. Swap batteries and see if the problem follows the battery or not.