Alpha Group OutBack Power FLEXmax Extreme Series User manual

FLEXmax Extreme Charge Controller
Owner’s Manual

About OutBack Power Technologies
OutBack Power Technologies is a leader in advanced energy conversion technology. OutBack products include
true sine wave inverter/chargers, maximum power point tracking charge controllers, and system communication
components, as well as circuit breakers, batteries, accessories, and assembled systems.
Grid/Hybrid™
As a leader in off-grid energy systems, which are designed around energy storage, OutBack Power is an
innovator in Grid/Hybrid system technology which provides the best of both worlds: grid-tied system savings
during normal or daylight operation, and off-grid independence during peak energy times or in the event of a
power outage or an emergency. Grid/Hybrid systems have the intelligence, agility, and interoperability to
operate in multiple energy modes quickly, efficiently, and seamlessly, in order to deliver clean, continuous and
reliable power to residential and commercial users while maintaining grid stability.
Contact Information
Address: Corporate Headquarters
17825 – 59th Avenue N.E.
Suite B
Arlington, WA 98223 USA
European Office
Hansastrasse 8
D-91126
Schwabach, Germany
T
elephone: +1.360.435.6030
+1.360.618.4363 (Technical Support)
+1.360.435.6019 (Fax)
+49.9122.79889.0
+49.9122.79889.21 (Fax)
Email: [email protected]
Website: http://www.outbackpower.com
Disclaimer
UNLESS SPECIFICALLY AGREED TO IN WRITING, OUTBACK POWER TECHNOLOGIES:
(a) MAKES NO WARRANTY AS TO THE ACCURACY, SUFFICIENCY OR SUITABILITY OF ANY TECHNICAL OR OTHER
INFORMATION PROVIDED IN ITS MANUALS OR OTHER DOCUMENTATION.
(b) ASSUMES NO RESPONSIBILITY OR LIABILITY FOR LOSS OR DAMAGE, WHETHER DIRECT, INDIRECT,
CONSEQUENTIAL OR INCIDENTAL, WHICH MIGHT ARISE OUT OF THE USE OF SUCH INFORMATION. THE USE OF
ANY SUCH INFORMATION WILL BE ENTIRELY AT THE USER’S RISK.
OutBack Power Technologies cannot be responsible for system failure, damages, or injury resulting from
improper installation of their products.
Notice of Copyright
FLEXmax Extreme Charge Controller Owner’s Manual © 2013 by OutBack Power Technologies. All Rights Reserved.
Trademarks
OutBack Power, the OutBack Power logo, FLEXpower ONE, and Grid/Hybrid are trademarks owned and used
by OutBack Power Technologies, Inc. The ALPHA logo and the phrase “member of the Alpha Group” are
trademarks owned and used by Alpha Technologies Inc. These trademarks may be registered in the United
States and other countries.
Date and Revision
June 2013, Revision A
Part Number
900-0150-01-00 Rev A

900-0150-01-00 Rev A 1
Table of Contents
Introduction................................................................................................................................................................. 5
Audience................................................................................................................................................................................................... 5
Features .................................................................................................................................................................................................... 5
Firmware................................................................................................................................................................................................... 5
Components and Accessories........................................................................................................................................................... 6
Battery Types..................................................................................................................................................................................... 6
Installation.................................................................................................................................................................... 7
Standards and Requirements............................................................................................................................................................ 7
Dimensions ........................................................................................................................................................................................ 7
Mounting the Charge Controller...................................................................................................................................................... 8
Installing the Fan .................................................................................................................................................................................10
Installing the AXS Card ......................................................................................................................................................................11
Wiring ......................................................................................................................................................................................................12
Grounding ........................................................................................................................................................................................12
Wiring Size and Requirements ..................................................................................................................................................12
Physical Requirements and Conduit .......................................................................................................................................13
PV and Battery Terminals ............................................................................................................................................................13
Accessory Terminals and Ports..................................................................................................................................................16
HUB/Display Port......................................................................................................................................................................16
Remote Temperature Sensor ...............................................................................................................................................16
AXS Card......................................................................................................................................................................................16
Fan Port........................................................................................................................................................................................16
Accessory Terminal Block ......................................................................................................................................................16
AUX Terminals .....................................................................................................................................................................17
Battery Sense Terminals ...................................................................................................................................................18
External Fault Terminals...................................................................................................................................................18
Power Up................................................................................................................................................................................................21
Setting the Nominal Voltage......................................................................................................................................................21
Resetting to Factory Defaults.....................................................................................................................................................22
Initial Operation ...................................................................................................................................................................................22
Status and Information..........................................................................................................................................23
LED Indicators.......................................................................................................................................................................................23
Modes of Operation ................................................................................................................................................................25
Bulk..........................................................................................................................................................................................25
Absorb....................................................................................................................................................................................26
Floating..................................................................................................................................................................................27
EQ.............................................................................................................................................................................................27
Silent .......................................................................................................................................................................................28
MATE3 System Display and Controller.........................................................................................................................................29
Battery Status Indicators..............................................................................................................................................................29
Charger Indicator ...........................................................................................................................................................................29
Charge Controller Soft Key .........................................................................................................................................................30
Status Screen .............................................................................................................................................................................30
Stats Screen......................................................................................................................................................................................31
Error Screen......................................................................................................................................................................................32
Temps Screen..................................................................................................................................................................................32
DataLog Screen ..............................................................................................................................................................................33

Table of Contents
2900-0150-01-00 Rev A
Graph Screens .................................................................................................................................................................................34
Programming the FLEXmax Extreme...............................................................................................................35
Menu Structure in the MATE3 .........................................................................................................................................................35
Charge Controller Settings...............................................................................................................................................................36
Charger..............................................................................................................................................................................................36
MPPT...................................................................................................................................................................................................37
Temperature Compensation......................................................................................................................................................38
Battery Equalize..............................................................................................................................................................................38
Grid-Tie Mode..................................................................................................................................................................................39
Auxiliary Output .............................................................................................................................................................................39
Auxiliary Mode Screens..........................................................................................................................................................40
Restart Mode ...................................................................................................................................................................................45
Calibrate............................................................................................................................................................................................45
Reset Charge Controller to Factory Defaults ........................................................................................................................45
Firmware Revision....................................................................................................................................................................46
Updating the Firmware ....................................................................................................................................................46
Device Data Logs .................................................................................................................................................................................47
Saving Data Logs for the FLEXmax Extreme.........................................................................................................................47
Data Log File Format .........................................................................................................................................................48
MATE/MATE2 Screens............................................................................................................................................49
Summary Screens................................................................................................................................................................................49
Status Screens.......................................................................................................................................................................................50
MODE Screens.................................................................................................................................................................................50
METER Screens................................................................................................................................................................................51
SETPT Screens .................................................................................................................................................................................52
LOG Screens.....................................................................................................................................................................................53
STAT Screens ...................................................................................................................................................................................54
Advanced Menus.................................................................................................................................................................................55
Accessing the Advanced Menus...............................................................................................................................................55
CHGR Menu......................................................................................................................................................................................56
CC ADVANCED Menu....................................................................................................................................................................57
EQ Menu............................................................................................................................................................................................58
AUX Menu.........................................................................................................................................................................................59
Troubleshooting ......................................................................................................................................................61
Specifications ............................................................................................................................................................63
Electrical and Mechanical Specifications.....................................................................................................................................63
Environmental Specifications..........................................................................................................................................................63
Regulatory Specifications .................................................................................................................................................................64
FCC Information to the User.......................................................................................................................................................64
Firmware Revision...............................................................................................................................................................................64
Temperature Range and Derating.................................................................................................................................................65
Default Settings and Ranges............................................................................................................................................................66
Applications...............................................................................................................................................................69
Array Design..........................................................................................................................................................................................69
Sizing Guidelines............................................................................................................................................................................69
Maximum-Power Voltage (Vmp).................................................................................................................................................69
Open Circuit Voltage (Voc) ...........................................................................................................................................................69
Weather Conditions ......................................................................................................................................................................70
Maximum Power Point Tracking ....................................................................................................................................................70
Three-Stage Battery Charging.........................................................................................................................................................71
Bulk .....................................................................................................................................................................................................71
Absorption .......................................................................................................................................................................................71
Float....................................................................................................................................................................................................72

Table of Contents
900-0150-01-00 Rev A 3
Equalize .............................................................................................................................................................................................72
Battery Temperature Compensation.......................................................................................................................................72
FLEXnet DC Battery Monitor (FN-DC) ...........................................................................................................................................73
Positive-Ground Systems..................................................................................................................................................................74
Networked Devices .......................................................................................................................................................................74
Non-Networked Devices..............................................................................................................................................................74
Grid-Interactive Settings ...................................................................................................................................................................75
Hydroelectric and Fuel Cell Applications Performance Optimization...............................................................................75
Auto Track Mode............................................................................................................................................................................75
U-Pick Mode.....................................................................................................................................................................................75
Definitions..............................................................................................................................................................................................77
Index.............................................................................................................................................................................79
List of Tables
Table 1Components Included ..................................................................................................................................................... 6
Table 2LED Indicators...................................................................................................................................................................24
Table 3Absorption Timer.............................................................................................................................................................26
Table 4Reasons for Silent Mode................................................................................................................................................28
Table 5Battery Status LED Indicators.......................................................................................................................................29
Table 6AUX Mode Functions......................................................................................................................................................40
Table 7Troubleshooting ..............................................................................................................................................................61
Table 8Electrical and Mechanical Specifications for All Models.....................................................................................63
Table 9Environmental Specifications for All Models..........................................................................................................63
Table 10FLEXmax Settings (MATE3)...........................................................................................................................................66
Table 11 Maximum Input Wattage Per Charge Controller..................................................................................................69
Table 12 Examples of Compensation .........................................................................................................................................73
Table 13 Terms and Definitions....................................................................................................................................................77

Table of Contents
4900-0150-01-00 Rev A
THIS PAGE INTENTIONALLY LEFT BLANK.

900-0150-01-00 Rev A 5
Introduction
Thank you for purchasing a FLEXmax Extreme Series Charge Controller. These charge controllers offer an
efficient, safe, multi-stage recharging process that prolongs battery life and assures peak performance from a
PV array.
Audience
This manual is intended for use by anyone required to install and operate this equipment. Be sure to review this
manual carefully to identify any potential safety risks before proceeding. Installers and operators must be
familiar with all the features and functions of this equipment before proceeding. Failure to install or use this
equipment as instructed in the manual can result in damage to the equipment that may not be covered under
the limited warranty. This product is only serviceable by qualified personnel.
IMPORTANT:
This manual provides safety guidelines and installation information for the FLEXmax
Extreme charge controller. It does not provide information about specific brands of PV
modules and supplies limited information on batteries.
Contact the supplier of the PV modules or batteries for additional information.
Features
The FLEXmax Extreme charge controller uses continuous Maximum Power Point Tracking (MPPT). This function
continuously seeks out the maximum power available from a PV array and harvests it. This power is used to
recharge the batteries. Without MPPT, the system can only harvest power at the level of the battery voltage.
See page 70 for a description of MPPT.
The FLEXmax Extreme has the following features:
Designed for FLEXgrid™ operation as part of an OutBack Grid/Hybrid™ system
Supports 12, 24, 36, 48, and 60 Vdc battery voltages
Performs voltage step-down capability allowing the use of a higher-voltage PV array configuration
Controls an equalization cycle manually or automatically
Capable of delivering full current without derating in temperatures up to 45°C (113°F)
Capable of full current without derating up to 55°C (131°F) when using optional fan kit
Rain-proof enclosure
Logs up to 128 days of operational data
Field-upgradeable firmware
Can be remotely monitored and configured (up to 300 feet or 100 meters away) using the optional MATE3
system display
Can be remotely monitored and upgraded using the optional AXS Card product
Firmware
This manual covers FLEXmax Extreme firmware revision 001.xxx.000.

Introduction
6900-0150-01-00 Rev A
Components and Accessories
Table 1 Components Included
1 x FM Extreme-150VDC
2 x Mounting Bracket 1 x Silicone Grease Package
2 x Ferrite Clamp, EMI Suppression (install on HUB/DEVICE port and RTS port; see page 16)
WARNING: Shock Hazard
This unit is not provided with a GFDI device. This charge controller must be used with
an external GFDI device as required by Article 690 of the National Electrical Code for the
installation location.
Figure 1 Features & Wiring Cover
Battery Types
The FLEXmax Extreme charge controller works best with lead-chemistry batteries intended for deep discharge.
These include batteries for marine, golf-cart, and forklift applications. They also include gel-cell batteries and
absorbed glass-mat (AGM) batteries. OutBack Power recommends the use of batteries designed specifically for
renewable energy applications. Lithium-based batteries and other advanced battery technologies may require
special considerations. Please contact OutBack Technical Support at +1.360.618.4363 before implementing
advanced battery technologies.
To remove the wiring compartment cover:
1. Using a Phillips screwdriver, remove the two
screws from the bottom of the compartment
cover. (See above.)
2. Grasp the lower edge as shown. Swing the
cover out while pulling downward.
Equalize switch
Status indicators
with universal symbols
Easily accessible
wiring
compartment
Rainproof
enclosure
Cover screws

900-0150-01-00 Rev A 7
Installation
Standards and Requirements
All installations must comply with national and local electrical codes. Professional installation is recommended.
A FLEXmax Extreme charge controller operating in unventilated or in other conditions where the ambient
temperature exceeds 45°C (113°F) will have a derated power output. See page 65 for more information.
If damaged or malfunctioning, the FLEXmax Extreme should only be serviced by qualified personnel.
Please contact the local renewable energy dealer/installer for assistance.
Dimensions
Figure 2 FLEXmax Extreme Dimensions
Width 8.8” (22.4 cm) Depth 6.0” (15.2 cm)
Height 18.6”
(47.1 cm)
Wiring box
height 4.4”
(11.2 cm)
Wiring box opening width 6.9” (17.6 cm)
For height with optional fan installed, see page 10
Side Plugs:
3.27” (8.3 cm)
Bottom Plugs:
3.3” (8.4 cm)

Installation
8900-0150-01-00 Rev A
Mounting the Charge Controller
The FLEXmax Extreme must be mounted upright on a wall or similar flat upright mounting surface. It must be
mounted at least 36” (91.4 cm) above the ground or floor. No other mounting positions are allowed. Installation
in shade is recommended.
Clearance requirements are a minimum of 6“ (15.2 cm) above and below the controller.
Two mounting methods are available. The first method uses keyhole slots on the back of the controller for
hanging directly on a wall. This method is useful for a standalone installation.
Figure 3 Mounting the Charge Controller (keyhole)
To mount using keyhole slots:
1. Use two slotted #14 wood screws. The mounting surface must be
strong enough to support the weight of the FLEXmax Extreme.
NOTE: OutBack is not responsible for damage resulting from
inadequate mounting hardware or preparation.
2. Mark the locations where the screws will be inserted on the surface.
Space them according to the keyhole slot locations (see below).
NOTE: The brackets included with the controller have holes with
the same spacing which can be used as a marking template.
3. Using the appropriate tools, set the screws into the surface
(see below). The heads should protrude by 1/8” (0.3 cm).
4. Hang the FLEXmax Extreme by placing its back against the
mounting surface and aligning the keyhole slots with the screws.
Settle the controller so that the screws are seated in the narrow end
of each slot.
5. Secure the base of the controller to the surface by inserting two ¼”
hex head lag screws into the holes shown to the left.
Slot spacing 7.9” (20.1 cm)
Hole spacing 5.5” (13.9 cm)
Distance
16.9” (42.9 cm)
Keyhole slots
Securing holes
Mounting is complete. Proceed to charge controller wiring or other installation steps.

Installation
900-0150-01-00 Rev A 9
The second mounting method uses brackets on the top and bottom of the controller. This method is useful
when mounting the controller next to an OutBack inverter system, as the conduit openings will align. It is also
useful for mounting without making advance measurements. The FLEXmax Extreme controller comes with two
identical brackets.
Figure 4 Mounting the Charge Controller (brackets)
To mount using brackets:
1. Using two ¼” hex head lag screws, mount the lower
bracket with the tabs facing upward. The mounting
surface must be strong enough to support the added
weight of the FLEXmax Extreme.
NOTE: OutBack is not responsible for damage
resulting from inadequate mounting preparation.
2. Lower the FLEXmax Extreme onto the bracket as
shown to the left. The bracket tabs can be inserted in
one of two positions: forward or rear.
To mount the controller flush against the wall,
insert the tabs in the forward slots as shown below.
To mount the controller 0.83” (2.1 cm) from the
wall to align with an OutBack mounting plate,
insert the tabs in the rear slots as shown below.
NOTE: The charge controller can rest on the lower
bracket for the rest of the procedure, although it will
need at least one hand to steady it.
3. Insert the upper bracket into the same set of slots as
were used with the lower bracket (forward or rear) as
shown to the left.
4. Using two ¼” hex head lag screws, attach the upper
bracket to the mounting surface as shown to the left.
Mounting is complete. Proceed to charge controller
wiring or other installation steps.
Forward
slot
Rear
slot
Rear
slot
Forward
slot

Installation
10 900-0150-01-00 Rev A
Installing the Fan
An optional fan is available for the FLEXmax Extreme to provide additional cooling. The fan is mounted on the
bottom of the charge controller. The total unit height with the fan attached is shown below. See page 65 for
information on the fan’s effects on unit performance.
Figure 5 Installing the Fan
To install the optional cooling fan:
1. Place the fan against the base of the FLEXmax Extreme.
T
he fan is equipped with two locking tabs. Two of the heat sink
fins have holes which receive the tabs. Align the tabs with
these fins (see below).
2. Press the fan straight along the fins until the tabs snap into
the holes.
3. Insert the fan connector into the fan
port in the controller’s wiring box. It
may be necessary to remove the rear
plug and insert a bushing. (See
illustration to the left; also see page 16.)
Installation is complete. The fan will
operate automatically based on the
FLEXmax Extreme internal temperature.
See page 32 to read the temperature using
the MATE3 System Display. This page also
lists the temperatures at which the fan
turns on and off.
Height
with fan
22.06” (56 cm)
Heat sink fins
Tab

Installation
900-0150-01-00 Rev A 11
Installing the AXS Card
An optional AXS Card enables Ethernet access to the FLEXmax Extreme using the Modbus protocol. (The AXS
Card is identical in function to the OutBack AXS Port product. See the AXS Port SunSpec Modbus Interface Owner’s
Manual for more information. NOTE: The AXS Port product is not interchangeable with the AXS Card and
cannot be used in this compartment.
Figure 6 Installing the AXS Card
To install the AXS Card:
1. Remove the factory-installed blank
compartment cover from the FLEXmax
Extreme. The cover is held in place with
two Phillips screws.
Installation is complete. See the
A
XS Port SunSpec Modbus Interface Owner’s Manua
l
for information on use.
Screws
2. Insert the AXS Card onto the rails
on each side of the compartment.
Slide it in until the card presses
firmly onto the connector at the
rear of the com
p
artment.
3. Install the alternate compartment cover
which was included with the AXS Card.
Use the Phillips screws which were
removed from the blank cover.
Insert
Screws

Installation
12 900-0150-01-00 Rev A
Wiring
This section provides instructions on installing PV array wiring into the charge controller. See page 69 for more
notes on PV array sizing. All wiring must comply with local and national codes.
Grounding
This product is intended to be installed as part of a permanently grounded electrical system. This is shown in the
wiring diagrams in this book. Grounding methods must comply with local and national codes.
The FLEXmax Extreme equipment ground is marked with this symbol:
IMPORTANT:
Article 690 of the NEC requires ground-fault protection such as the OutBack GFDI.
It is recommended to bond one of the DC conductors to the ground on the battery
side of the system.
The DC conductor is connected to the ground as a result of installing the OutBack
GFDI. They should not be bonded separately. If a separate bond is already present
in the system, it should be removed. If present, it will defeat the GFDI protection.
(See page 19.)
Bonding the negative and ground is most common. However, the FLEXmax
Extreme can be used normally in either negative-ground or positive-ground
systems. Page 14 shows examples of both types of system wiring. See below for
restrictions on positive grounding. Also see page 74.
CAUTION: Equipment Damage
The FLEXmax Extreme can be used in a positive-ground system when networked with
one OutBack inverter. This requires a HUB Communications Manager. (See page 15.)
It cannot be networked in a positive-ground system with multiple inverters. For use of
the FLEXnet DC Battery Monitor or other devices in these applications, see page 74.
Failure to follow these instructions can damage the controller and other devices. This
damage is not covered under warranty.
The following important restrictions apply unless superseded by local or national codes:
The grounding conductors must be routed separately from all battery conductors.
The battery conductor (positive or negative) must be bonded to the grounding system at only one point.
Wiring Size and Requirements
IMPORTANT:
Wire sizes must comply with local and national codes. Input conductors and circuit
breakers must be rated at 1.56 times the short-circuit current of the PV array (per NEC).
OutBack 100% duty continuous circuit breakers only need to be rated at 1.25 times the
short-circuit current.
Please refer to the NEC and other electrical codes for PV array cable sizing, cable length, and cable ampacity.
Use #4 AWG (25 mm2) wire (minimum) for the output between the FLEXmax Extreme and the battery bus
bar conductors. Smaller cables can reduce performance and possibly damage the unit.
The output can accept up to #2 AWG (35 mm2) wire. Larger conductors will reduce losses and ensure
highest performance of the FLEXmax Extreme.
Install properly sized overcurrent protection devices. The required AIC rating of the device is 4000 Adc.

Installation
900-0150-01-00 Rev A 13
The largest PV array must have a rated short-circuit current of 64 amps or less under STC (Standard
Test Conditions). The output current limit of the FLEXmax Extreme is 80 amps.
DC battery overcurrent protection must be used as part of the installation. OutBack offers both circuit
breakers and fuses for overcurrent protection.
Physical Requirements and Conduit
IMPORTANT:
Conduit hubs must connect to the conduit before connecting to the FLEXmax Extreme.
WARNING: Burn Hazard
The heat sink can become hot when the charge controller is operating. Use caution
when touching it during operation.
All wire lugs and ground terminals are to be tightened to a torque value of 4 Nm (35 in-lb).
Use copper wiring only. Wiring must be rated at 90°C or higher.
If installing in a wet location, any conduit hubs must comply with the requirements of UL 514B.
Run positive and negative cables side by side.
~Tie or twist cables together as much as possible to allow the inductive currents to cancel.
~Ensure paired cables pass through the same knockout and conduit fittings.
PV and Battery Terminals
WARNING: Shock Hazard
When a PV array is exposed to light, it immediately generates a voltage. Make sure all
DC circuit breakers are OFF (open) BEFORE making any wiring connections. Open both
the battery disconnect devices and the array disconnect devices to ensure isolation of
the controller. Use a DVM to check for voltage on all wires.
CAUTION: Equipment Damage
Each FLEXmax Extreme requires its own PV array. DO NOT PARALLEL PV+ and PV-
TERMINALS OF MULTIPLE CONTROLLERS ON THE SAME ARRAY!
The negative (-) PV and negative (-) BAT terminals are connected internally. Only one wire is needed to connect
to the negative (-) wire lugs if the negative (-) PV and BAT conductors are bonded at the negative bus bar.
See Figure 8, Figure 10, Figure 16, and Figure 17 for sample wiring diagrams.
Figure 7 Wiring Compartment
DC TERMINALS
PV + PV - BAT - BAT +
DC
Terminals Ground
Bus

Installation
14 900-0150-01-00 Rev A
Figure 8 Wiring Diagram – Single Charge Controller with PV Array
Figure 9 Wiring Diagram – Single Charge Controller (Positive-Ground)
NOTE: Ground Fault and system-specific
wiring not shown
NOTE: Ground Fault and system-specific
wiring not shown

Installation
900-0150-01-00 Rev A 15
Figure 10 Wiring Diagram – Charge Controller with PV Array and Inverter
CAUTION: Equipment Damage
The FLEXmax Extreme can be used in a positive-ground system with one OutBack
inverter as shown above. It cannot be used in a positive-ground system with multiple
OutBack inverters. For other devices or configurations, see page 74.
NOTE: Ground Fault and system-specific wiring not shown

Installation
16 900-0150-01-00 Rev A
Accessory Terminals and Ports
Figure 11 Wiring Compartment
HUB/Display Port
This is an RJ-45 port for a CAT5 cable to connect OutBack system displays or communications managers. A
ferrite clamp (see page 6) should be installed on this cable inside the compartment.
Remote Temperature Sensor
An optional battery Remote Temperature Sensor (RTS) is recommended for accurate battery charging. A ferrite
clamp (see page 6) should be installed on this cable inside the compartment.
When the system includes an OutBack HUB Communications Manager and a system display, only one RTS is
needed for multiple inverters and charge controllers. Specialized temperature compensation is available.
See page 38 for more information.
AXS Card
This is the location for the AXS Card, which is available as an option for the FLEXmax Extreme. See page 11.
Fan Port
This is the connection for the FLEXmax Extreme cooling fan. See page 10.
Accessory Terminal Block
This block of terminals has connections for the AUX output, for the Battery Sense function, and for the External
Fault function. The terminals accept wire from 16 AWG to 24 AWG.
Figure 12 Accessory Terminal Block
External
Fault
AUX
Battery
Sense
AXS Card
(optional)
Accessory Terminal Block
Fan Connector
Remote
Temperature
Sensor (RTS) Port
HUB/System Display Port

Installation
900-0150-01-00 Rev A 17
AUX Terminals
The AUX (Auxiliary) output is a small power supply that provides a 12 Vdc output current to an isolated load. The
AUX output can respond to many criteria and control many functions. These include cooling fans, vent fans,
load diversion, fault alarms, and automatic generator control. The AUX can only control one function at a time.
Terminals and are the + and – terminals for the AUX output. These terminals are colored gray (–) and
brown (+) for easy reference. The terminals can supply up to 250 mA at 12 Vdc (3 W). The AUX circuit contains
electronic overcurrent protection, which resets after being overloaded. No additional fuses are required for the
AUX terminals.
The AUX LED illuminates when the output becomes active. (See page 23 for an illustration of LED indicators.)
Figure 13 AUX Vent Fan
Figure 14 AUX Diversion Control
In this example, the AUX output directly drives a
12-volt vent fan. The – and + wires on the fan are
connected to terminals and , the AUX– and
AUX+ terminals.
In this example, the AUX output drives a relay that
diverts wind power. The relay’s coil is connected to
terminals and , the AUX+ and AUX–
terminals. When the AUX output closes the relay
(based on battery voltage), the relay diverts excess
power to a water heating element.
Relay
Element
Turbine
NOTE: Relays and elements shown are examples only and may
vary depending on the installation.

Installation
18 900-0150-01-00 Rev A
Battery Sense Terminals
The remote Battery Sense terminals are used for accurate voltage monitoring. These terminals connect directly
to the batteries. Using the controller’s main battery cables for voltage sensing is less accurate. This is due to
voltage rise caused by charging currents on the battery conductors.
Terminals and are the – and + terminals for the Battery Sense function. These terminals are colored
black (-) and red (+) for easy reference. A twisted-pair cable is recommended. (See wire sizing on page 16.)
IMPORTANT:
The MATE3 display shows the system voltage as measured at the battery terminals of
various devices. (See Figure 26 on page 29.) This voltage is used for generator starting
and other functions.
If no other devices are present, it will show the reading of the FLEXmax Extreme.
If OutBack inverters are present, the inverter voltage replaces the FLEXmax
Extreme as the system voltage reading.
If the FLEXmax Extreme Battery Sense terminals are in use, this reading replaces
the inverter or the regular charge controller readings as the system voltage.
The FLEXnet DC Battery Monitor is the highest priority and will replace the
Battery Sense reading as the system voltage.
The Battery Sense reading is still shown on the Charge Controller screen. (See Figure 27
on page 30.) This reading is still used to adjust the FLEXmax Extreme charging.
This function operates automatically when it detects a voltage within 2 volts of the battery voltage reading at
the charge controller’s main terminals. If the reading varies by more than 2 volts, the Battery Sense function is
disabled. The assumption is that the terminals are not connected. (If the terminals are connected, there may be
a wiring problem.)
The MATE3 allows the user to calibrate the battery meter at the charge controller’s main terminals. (See page 45
and the MATE3 manual for more information.) This calibration does not affect the Battery Sense function. If
Battery Sense is in use, calibration changes can be made, but will have no effect until Battery Sense is disabled.
Figure 15 Battery Voltage Sensing
External Fault Terminals
The External Fault terminals are used to make connections to the OutBack Ground Fault Detector/Interruptor
(GFDI) product. A single wire is run from one of the yellow terminals ( or ). A second single wire is run
from one of the purple terminals ( or ). Terminals and are the most commonly used. These wires
are connected to a normally-open set of contacts on the OutBack GFDI. Figure 16 and Figure 17 show terminals
to without the rest of the control terminal block.
NOTE: Overcurrent protection is
not shown. Recommended
protection for sense conductors is:
Fast-acting device
80 Vdc or greater
1 A or smaller
Cold resistance 10 ohms or less