Installation Manual

Page 88
© 2014 Magnum Energy, Inc.
Using a BMK: Setup
8.0 Using a BMK
This section discusses how to set up and monitor Magnum’s BMK (battery monitor kit) using the
menu options in the ME-ARC remote.
IMPORTANT: A BMK must be connected and communicating with the ME-ARC in order to set up
and/or monitor its operation. If the BMK is not communicating or no BMK is connected, “No BMK
Present” appears when accessing the METER: 05 BMK Meters and SETUP: 05 BMK Setup menus
(unless the TECH: 07 Show all Menus menu is set to “Yes”). Refer to Section 3.2.5 for more in-
formation on the TECH: 07 menu.
8.1 Setting Up the BMK using the ME-ARC
Use the BMK SETUP menus to establish your battery’s charge effi ciency and to set the capacity
of the battery bank (AH size).
SETUP: 05 BMK Setup
This section provides information about charge effi ciency and how to manually access/adjust this
setting and the amp-hour setting.
• 05A Charge Effi ciency – This setting allows the battery monitor to calculate the battery’s
charge effi ciency. The charge effi ciency can be calculated automatically using the Auto setting,
or can be calculated based on a fi xed effi ciency value determined by the user.
Default setting: Auto
Range: Auto, 50%-99%
What is charge effi ciency? When a certain amount of energy is removed or discharged from
the battery, this removed energy will need to be returned to keep the batteries at a 100% state
of charge. As batteries are being charged, they lose energy; either in the form of heat, or while
gassing. This loss of energy while charging means the battery will not be fully charged if you only
return the current that was removed. To compensate for the battery’s ineffi ciencies while charging,
a charge effi ciency setting is provided. The charge effi ciency setting compensates the METER: 05E
AH In/Out reading by ensuring the AH returned to the battery are greater than the AH removed.
Example: The 05E AH In/Out display reads 000 and you begin powering a 25-amp load for two
hours—the display will show -050. This indicates that you have discharged 50 AH (2 x 25) from
the battery. If the charge effi ciency setting is set to 95%, then as you begin charging and return
50 AH, the AH I/O reading will be less than zero, indicating that the AH removed have not been
fully returned. The 95% charge effi ciency setting requires 52.5 AH (50/95) to be returned before
the AH I/O returns to 0.
CAUTION: The factory default charge effi ciency setting is Auto, which allows charging
effi ciency to be automatically calculated. In most circumstances, this setting determines
the best charge effi ciency. If you do not know your battery’s charging effi ciency, leave
it at the factory default setting. If the setting is manually set but incorrect, the state-of-
charge information will become more inaccurate with every charge.
Adjusting the Charge Effi ciency Setting: The battery monitor is shipped with the charge ef-
fi ciency set to Auto. This allows the battery monitor to automatically calculate variables that affect
the charging effi ciency, such as battery type, battery age, and how the batteries are maintained—
which is not always constant. With the Auto setting, the effi ciency is recalculated each time the
batteries reach a 100% state of charge (SOC).
This setting can also be manually adjusted from 50% to 99% if the battery’s charge effi ciency is
known. With a setting other than Auto, the battery monitor uses the manual setting to calculate
the METER: 05E AH In/Out display. For example, if you set the charge effi ciency to 90% and 100
AH are removed from the battery, the AH In/Out display would read 000 only after 111 AH have
been returned to the battery. However, if the charge effi ciency is manually set and inaccurate,
the SOC information will be more inaccurate with every charge. Thus, continually monitor the AH
I/O reading (along with the SOC display) under the remote’s METER button.
After several charge and discharge cycles (below 80% SOC), the AH I/O reading should be slightly
positive when the SOC display reads 99%.