12EXB Battery Monitor
 Designed by boaters for boaters, the 12EXB will provide many years of service with little or no maintenance.

There are many methods of determining the remaining capacity of a 12V battery. The most
complicated systems measure the current going in and out of the battery and calculate the remaining
capacity. An accurate indication can be impossible due to  many variables such as age of the
battery, temperature, inter cellular specific gravity  differentials, charge method and load
conditions just to name a few. Most of these systems are costly and their accuracy will be compromised
 by the above cited conditions. Although direct measurement of specific gravity with a hydrometer or refractometer is the most accurate measure of battery condition, It is not a task you will want to do on a daily basis, although it should be performed quarterly at the least. Since specific gravity readings can not be  performed on sealed batteries a reliable  method of determining voltage is the closest we can come. An accurate expanded scale meter and a little battery knowledge and experience will tell you what you need to know.
Expanded Scale Mode
The 12EXB is an expanded scale voltmeter designed to give you a detailed view of battery system  voltage. The
difference between a fully charged battery and a dead battery can be as smallas 0.500 V.  It would be very costly to design a meter that could display all of the digits in a 12.500 V reading. In the expanded scale mode the 12EXB removes the 12V from the display and allows a reading of .001V.  For example: 12.789V would display 0.789V in the expanded scale mode and the
reading 11.500V would show -0.500V. With brief use, you will begin to understand how your batteries behave under various conditions. If you have multiple batteries, with selective switching, you can compare the reading to determine which battery is stronger.
Maximum Hold
When the 12EXB is in this mode, the meter will store the highest voltage reading measured. This information tells you
how high the battery voltage rose during charging, which in turn tells you whether or not your charging sysytem is completely charging your batteries.
Back Light
The back light will brightly light when the button with the "sun" symbol is pressed. To conserve energy, the
backlight is only lit when the button is pressed.
Using the 12EXB
The 12EXB can be used as a valuable tool to troubleshoot various problems in the electrical system.

Charging - When the alternator or other charger is on, voltage should slowly increase and should then stabilize when the battery is charged. In the case of a programmable 3 stage regulator or charge controller, voltage should incease to the bulk/absorption value, typically 14.4-14.6 volts with flooded batteries and then drop to float, typically 13.1-13.3 volts. If this sequence is observed you know your charger/regulator system is functioning as it should. This information is especially valuable with AGM batteries as the lower voltages required to prevent dangerous thermal runaway can be accurately set(assuming variable voltage settings are available on the charging system) and monitored.

Loads - As various loads are turned on, a voltage drop will be seen. A water pump can drop voltage 1.0 V while an overhead light may create only a  0.2  volt drop.. If there is a short or other problem or you forgot to turn off the engine room lights the voltage  will drop more than normal. For Example: A higher than normal voltage drop could tell you that your water
pump has a bad bearing. Voltage - The best time to determine the full charge voltage is with no load or charge input on the battery for 10 or more minutes. This voltage can be used as a reference point. A good time to look at this voltage
is when you first turn on power when your about to go boating for the weekend. If the battery voltage is lower than normal you should check the battery and electrical system for problems.

Face dimensions;3 .75" long x 1 .75" tall

Minimum depth required with out considering panel thickness 2.5"

Cutout; 3.3125 (3 5/16) " long x 1.625 (1 5/8) " tall

Screen dimension; 1.75 " long x 1.125 (1 1/8) " tall

LCD characters; slightly over 1/2" tall, very readable.


Warranty and Repair
The 12EXB is warranted to be free from defects for one year from the date of purchase. If the 12EXB
needs repair send it  and a copy of the receipt to:
Service & Repair
Shoreline Electronics, Inc.
2102 Walsh Ave. Suite F
Santa Clara, CA 95050

If you have trouble installing or have questions about
the 12 EXB please contact;
DC Dynamics Div.
Southeast Marine Services, LLC
800-487-0610
info@semarine.com

Detailed instructions with each meter