Magnum Energy ME-ARC50 Owner'S Manual Download

Page: 96 / 139

2014 Magnum Energy, Inc.

Page 89

Using a BMK: Monitoring

To view the SOC display:

Access the

METER: 05B Battery SOC

display. If the

AH I/O

reading

is below 000 (negative number) when the

SOC

display reads 99%, then increase the charge ef-

ciency setting. If you

nd that the

AH I/O

reading is substantially above zero when the

SOC

display reads 99%, then decrease the charge ef

ciency setting.

• 05B AmpHour Size

– This setting is used by the battery monitor to calculate the battery’s

SOC. The AH size represents the amount of energy the battery can deliver.

Default setting:

400 AH

Range:

200-2500 AH

Note:

It is important that the

AmpHour Size

setting is correct or else the calculations used to

determine the battery’s SOC display will be inaccurate.

Where do I set the AmpHour Size setting?

Select the setting based on the 20-hr AH capacity

of your battery bank. Refer to the battery manufacturer for the 20-hr AH capacity of your par-

ticular batteries.

How do I determine my Battery Amp-Hour capacity?

The batteries should be a deep-cycle

type and rated either by AH or reserve capacity in minutes.

• Amp-hour (AH) capacity is a measurement of how many amps a battery can deliver for a

speci

ed length of time (usually 20 hours) until the voltage achieves 1.75 VDC/cell at 80°F.

• Reserve Capacity (RC) is a measure of how many minutes a battery can deliver a certain

amount of current (usually 25A) and maintain a voltage above 1.75 VDC/cell at 80°F. If us-

ing the Reserve Capacity (25A), the 20-hour AH capacity can be estimated by multiplying

‘minutes reserve capacity’ by 50%.

Note:

For batteries in parallel strings – add the AHr capacity of each string (Ex.: three 250AH

batteries in parallel = 750 AH); for batteries in series – use the amp-hour capacity of one battery

(Ex.: three 250 AH batteries in series = 250 AH).

8.2

BMK Operation/Monitoring with the ME-ARC

This section explains how the ME-BMK (Battery Monitor kit) battery monitor works, and how to

use the ME-ARC to obtain battery bank information. It also covers the various LCD displays that

are related to the battery monitor and the status of the sense module’s LED indicator.

8.2.1

How does the BMK Battery Monitor Operate?

The ME-BMK uses a precision resistor—known as a shunt—to measure current

ow into and out

of the battery. The shunt provides a small voltage to the BMK sense module that is proportional

to the current

ow. When the battery current starts

owing, the sense module measures the

amount of current removed from and returned to the battery. The amount of current (or AH)

removed or returned is displayed as the

METER: 05E AH In/Out

value. This

AH In/Out

value is

compensated by the

SETUP: 05A Charging Ef

ciency

value that accounts for energy loses while

charging, and is one of the factors used to determine the battery’s State Of Charge (SOC).
The battery’s state of charge—which is the best indicator of the condition of the batteries—is

indicated on the

METER: 05B Battery SOC

display. This display shows that the batteries are fully

charged (i.e., SOC = 100%) once the following three conditions have been met:

1. The charging voltage has stabilized over a period of time (see Figure 8-1).
2. The charging current has decreased to a low % of the AHr capacity—normally less than 2%.
3. The AH that were removed from the battery are within 1% of fully being returned.

When the BMK sense module is

rst connected, the batteries will need to be fully charged (i.e.,

SOC = 100%) at least once to establish a SOC reference point. While this reference point is being

calculated, the

METER: 05B Battery SOC

display shows “

Think’n

” to indicate that the SOC refer-

ence point is calculated. After the batteries are fully charged, the display changes from “

Think’n

”

to “