Installation Guide

975-0691-01-01 Revision B 3-35

To display the mid-point voltages on the Battery Monitor, press the right arrow

key until the AUX Voltage label is shown. The voltage display on the LCD display

will alternate every 5 seconds between VA1 and VA2 voltages.

Trending Mid-point Voltages in Data Logs

By keeping track of the mid-point Va1 & Va2 between the two battery strings, it is

possible to know if both strings are remaining balanced during charge and

discharge cycles. The most obvious differences can be observed when the

battery is in the range of 70-50% SOC. The effect gets more pronounced as the

cell voltage nears the knee voltage common with lead-acid batteries (i.e.

discharge voltage of the battery after which there is little energy capacity left).

Typical voltage difference of less than 0.5 V to 1 V are acceptable, but when

voltages start to differ beyond 1.5 V for two center taps of a parallel battery

string, it usually means the cells of one string have diverged and need periodic

maintenance (a visual check, water top-up, or equalization, etc.)

Va1

Va2

Va1Vm

Va2

2x 2AT fuse

2AT fuse 2AT fuse

2AT fuse

Method 1:

Method 2 (parallel battery banks):

Each battery icon represents a 6 V cell.

Figure 3-6 Mid-point sensing configurations