BATTERY CONDITION TABLE
Specific Gravity
Measured by
State of
Hydrometer
Open Circuit Voltage
Discharge @ 80° F
12 Volt System 24 Volt System
1.265
12.6 or more
25.2 or more
Fully Charged
1.225
12.4
24.8
25 % Discharged
1.190
12.2
24.4
50 % Discharged
1.155
12.0
24.0
75 % Discharged
1.120
11.7 or less
23.4 or less
100 % Discharged
* Note: Wait at least 5 minutes after charging or discharging before checking
specific gravity or open circuit voltage. The battery’s voltage needs to stabilize in
order to get an accurate reading.
Troubleshooting Your Battery System
If your battery will not accept or hold a charge, one of the following conditions may
exist:
1. A BAD BATTERY. You may have a battery with an open or shorted cell, a battery
without any “life” left. Check by charging the battery until all cells have a specific
gravity of 1.225 or greater at 80° F. If you are unable to obtain 1.225 in each cell,
replace the battery.
2. A BAD BATTERY CHARGER. If the battery open circuit voltage is low and/or the
hydrometer indicates your batteries are low, the battery charger should be providing
current to the batteries. If it is not, check the input fuse and check to see that you
have charging voltage on the output with no battery attached. Note: You will not get
an accurate voltage reading on the output of the charger with no batteries attached.
This is checked merely to ensure that you do not have an open circuit on the output.
The battery charger has a thermal power reduction circuit to protect the charger
from overheating. If you suspect this is the case, refer to the INSTALLATION section
for information about proper charger location. See also Cooling Fan on page 21.
3. ELECTRICAL LEAKAGE. You may have a previously unsuspected source of
current drain from the battery. To check for a leakage of this sort, disconnect the
battery ground cable and connect an ammeter between the negative battery post
and ground. If you have a reading over .1 amp, there is a source of current drain
from the batteries which must be located and removed.
IX) REFERENCE APPENDIX
* For more information about boat wiring to conform to U.S. Coast Guard regulations,
write to:
Superintendent of Documents
Request : 33 CFR 183 Subpart I
Government Printing Office
Washington, DC 20402
* For information about American Boat and Yacht Council recommendations for
boat wiring, write to:
American Boat and Yacht Council
3069 Soloman’s Island Road
Edgewater, MD 21037
Request: Standards and Recommended Practices for Small Craft.
AC systems: Section E8
DC systems: Section E9
A-20: Battery Charging Devices.
* For additional installation instructions, refer to:
ANSI NFPA 302
30
31
All manuals and user guides at all-guides.com
all-guides.com