Outback Power Integration Guide

REV042920
SimpliPhi Power, Inc. | 3100 Camino Del Sol | Oxnard, CA 93030, USA | [phone] | [e-mail]| SimpliPhiPower.com
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CAUTION: Not all grid-tie inverters (including micro-inverters) successfully AC Couple with
battery-based inverters. Some grid-tie inverter manufacturers require specific updates to
their equipment (via their Support staff) when configuring an AC Coupled system. Make sure
to contact the relevant grid-tie inverter manufacturer regarding the feasibility of AC Coupling
prior to an AC Coupled installation using OutBack equipment and SimpliPhi batteries.
CAUTION: Radians operate in Grid Tied or Generator modes only when AC Coupled; they do
not operate in Mini Grid or Grid Zero modes when AC Coupled. SkyBox AC Coupling allows
for inverter operation in additional modes. For more information on this, refer to the above
linked AC Coupling Application Notes or contact OutBack Power: [e-mail].
Sizing for Maximum Instantaneous Charge Rate (AC Coupled)
Minimum Battery Quantity per inverter calculation results are listed below. These calculations assume that the AC
Coupled grid-tie inverter used in the system fulfills the maximum allowable rating according to OutBack’s AC Coupling
guidelines. When AC Coupling to a grid-tie inverter with a rating lower than described in the table below, or when using
more than one inverter in a system, PHI Battery bank sizing is more precise when the calculation described in the
example above is used instead of the following table.
48V Inverter Model
Inverter Power
Rating (kW AC)
MAX AC Coupled GTI
Rating (kW AC)
PHI 3.8-51.2V
nom
MIN Battery Quantity
PHI 2.9-51.2V
nom
MIN Battery Quantity
OutBack Radian 8048A 8 7.6 4 5
OutBack Radian 4048A
4
3.8
2
3
OutBack SkyBox 5
5 (non-UL1741SA
compliant) or up to 7.6
(UL1741SA compliant
inverters only)
4 6
3.4 – Overall Battery System Sizing
Size the PHI battery bank so that the minimum number of batteries in the bank is the greater of the two figures
obtained from the Discharge and Charge calculations. For example, a system that requires 5 PHI Batteries to
ensure that the battery bank does not over-discharge and 3 PHI Batteries to ensure that the battery bank does
not over-charge, should include a final minimum quantity of 5 batteries. Failure to do so will destroy the PHI
batteries and will Void the Warranty.
Note that these sizing guidelines and program settings outlined in Section 4.0 – Program Settings for PHI
Batteries assume that solar PV charging and charging via the inverter/charger do not occur simultaneously. If
there is a possibility that these two charging sources might be active at the same time in your system, please
consult OutBack Power (
[e-mail]).