VANNER
Incorporated
Installation Instructions
Ruggedized Battery Equalizer OWNER’S MANUAL
10
Wire Size and temperature rating
Cables connecting the equalizer to the batteries must be sufficiently sized to prevent unwanted voltage
drops. To properly maintain battery voltage balance, the voltage drop (loss) must be less than 0.05 VDC
between the equalizer +24 volt terminal and the battery +24 volt terminal (Battery B positive terminal);
less than 0.10 VDC between the equ12 volt terminal and the b12 volt terminal (the jumper
between Battery A and Battery B); and less than 0.05 VDC between the equalizer GND terminal and the
battery ground terminal (Battery A negative terminal that is connected to chassis ground). In most
installations, the equalizer terminals are wired directly to the battery terminals (reference fault protection)
to prevent voltage loss that could occur in switch contacts, connections, and long wire runs.
Wire and Fuse Size Chart
Wire Size
AWG
Max wire length, in feet, between equalizer and battery to keep voltage drop under 0.1 volt. The
chart assumes the wire carries no other load and wire temperature is below 80ºC.
71 Series
2 X 71 Series
#4
3.5
XXX
#2
5.2
2.6
#1
6.5
3.3
#1/0
8.3
4.1
#2/0
10.5
5.3
Fuse F1
125 amp
250 amp
Fuse F2
80 amp
150 amp
Verify Equalizer Operation
Before testing the equalizer, be sure all battery connections are good and that fuses F1 and F2 are good.
Equipment Required
•
VoltMeter having 0.01 volt resolution. (Fluke Model 87 Multimeter recommended). (Use two
multimeters if it is desirable to see the voltages of Battery A and Battery B at the same time.)
•
Clamp-on amp meter (Fluke Model 36 Clamp-on Meter recommended).
The equalizer is working properly if:
1. The 12 volt DC loads are being operated continuously and are within the rated capacity of the
equalizer and;
2. Battery A voltage is lower than Battery B by no more than 0.05 to 0.10 volts, measured at the
equalizer’s +24, +12 and GND terminals.
