Outback Power Systems FLEXmax Extreme Owners Manual - Manual (Page 75)

Applications
900-0150-01-00 Rev A 73
The FLEXmax Extreme controller, when equipped with the Remote Temperature Sensor (RTS), will compensate
for temperature. The RTS is attached to a single battery near the center of the bank. When charging, the RTS will
increase or decrease the charge voltage by 5 mV per degree Celsius per battery cell. This setting affects the
Absorbing and Float set points. Equalization is not compensated in the FLEXmax Extreme.
There can be side effects to temperature compensation. During cold weather, a battery often requires a higher
charging voltage. Some inverters might not accommodate these higher voltages and can shut down during
charging, cutting off power to their loads. In addition, some battery manufacturers specify not to exceed a
certain voltage due to the risk of battery damage.
To accommodate these problems, the FLEXmax Extreme has adjustable compensation limits. It also has an
adjustable rate of compensation (“slope”) to meet the requirements of certain batteries. The default slope value
is 5 mV per degree C.
When the system includes an OutBack HUB Communications Manager and a system display, only one RTS is
needed for multiple inverters and charge controllers.
See page 38 for more information on these items.
Table 12 Examples of Compensation
Cells (volts) Slope Value Temp 25° ± Calculation Total Compensation
6 (12V) 5 mV 8°C -17 6 x 0.005 x 17 +0.5 Vdc
12 (24V) 3 mV 36°C +11 12 x 0.003 x 11 -0.4 Vdc
18 (36V) 5 mV 26°C +1 18 x 0.005 x 1 -0.1 Vdc
24 (48V) 6 mV 0°C -25 24 x 0.006 x 25 +3.6 Vdc
30 (60V) 2 mV 37°C +12 30 x 0.002 x 12 -0.7 Vdc
FLEXnet DC Battery Monitor (FN-DC)
The OutBack FLEXnet DC will work normally if it is networked with the FLEXmax Extreme and OutBack inverters.
This requires a HUB Communications Manager.
If the FN-DC is networked exclusively with FLEXmax Extreme charge controllers and a HUB product, the FLEXmax
Extreme AUX– terminal must be connected to the battery negative conductor. (This item is terminal on the
Accessory Terminal Block.) The FN-DC will not function until this is done.
Any devices connected to the AUX+ and AUX– terminals should be electrically isolated. (Examples include, but
are not limited to, coil relays, optical isolators, or fans.)
CAUTION: Equipment Damage
Using non-isolated devices in this application can damage the controller and other devices.
This damage is not covered under warranty.
Figure 64 Adapting for the FN-DC
Connect to
battery
negative