11.8 volts

Status
Not open for further replies.
G

Greg

I installed a new battery at the beginning of the season due to one of them being bone dry and dead as a door nail. After installing the new battery every thing seems to work fine but the meeter at the nav station reads only 11.8 volts. the GPS confirms this because it reads the same thing. Is this normal due to using power at the time? The boat has a automatic charging system to keeps them charged when plugged into shore power, but the batteries never seem to get fully charged.
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
voltage loss

Lots of possibilities here, but first I would consider where you are taking the voltage reading from. If your volt meter is attached to a hot lead, anywhere beyond the battery switch, you are getting a reading after instruments and whatever else is turned on are drawing current, which does give you a voltage drop, although shouldn't be that much. Also, if you have the normal analog type of volt meter, they are not known for accuracy. Get a digital volt meter, and take your readings at the battery. This way you know if the battery is fully up and you are or are not loosing voltage somewhere in the system.
 
Aug 9, 2005
772
Hunter 28.5 Palm Coast, FL
A filly charged battery should read 12.6 to 12.8..

volts. Your battery charger should put our at least 14 volts, If it doesn't you charger may be bad.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Bad battery?

Voltage State of Charge 12.6+ 100% 12.5 90% 12.42 80% 12.32 70% 12.20 60% 12.06 50% 11.9 40% 11.75 30% 11.58 20% 11.31 10% 10.5 0% You may want to pull your battery and put it on a stand alone charger. If it does not come up to 100%, take it back to the shop where you purchased it for their evaluation. If you can pull 12.6v from another charger, you may want to consider replacing the charger or having it evaluated.
 
Oct 3, 2006
1,016
Hunter 23 Philadelphia
"State of charge" ??

I was alwyas taught that, if yu want to check your battereis state of charge, have someone monitor the voltage at the battery, while you turn your starter over. If it holds greater than 9.5 volts (while cranking), your battery is in good shape. (This is for a lead-acid car battery). It's a pretty good test if you've got electric start...
 

GuyT

.
May 8, 2007
406
Hunter 34 South Amboy, NJ
Not exactly Steve

Steve, you cant make a correlation between battery volage and state of charge unless it is an open circuit voltage measurement - i.e. no load connected. If there is load connected, you need to know the discharge current. Your numbers may work for you but not for others. And BTW the numbers you posted do not jive for open circuit measurements. Greg, you may have an undersized charger. What is your chargers current capability? What is the size of the battery? Also, how much current are you using from your battery when at the dock?
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
The quick way

Since your GPS and volt meter are in agreement try this to see the real battery voltage quickly. Turn off everything and read the voltage on the volt meter. With no current flowing the voltage at where ever the voltmeter is attached will be the same as at the batteries. If it still reads 11.xx then you either have a charging problem or more likely a serious connection problem. Try cleaning the battery posts. If it reads something normal try turning on something that draws 4-5 amps. If it goes back to 11.x volts then you have a connection problem. 99.44% of all low voltage problems are the connection at the battery. All that acid you know.
 
G

Greg

OOPS!

Sorry guy's, my mistake. I was looking around for the possible problem and realized that the charge was not even working. I started flipping some switches and the charger lit up like a christmas tree (DUH. The switch was labeled inverter. We just bought this boat in May and still trying to figure out what the previous owner did. Now the meeter reads 12.9 volts. Thanks to everybody that tried to help.
 
May 14, 2004
99
Catalina Capri 22 Town Creek, MD
Wish everything was that easy to fix

Would that electrical gremlins disappeared with the flick of a switch.
 
Status
Not open for further replies.