Outback Power Integration Guide
Table Of Contents
REV042920
SimpliPhi Power, Inc. | 3100 Camino Del Sol | Oxnard, CA 93030, USA | (805) 640-6700 | info@simpliphipower.com| SimpliPhiPower.com
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In the case where the inverter’s AC Power Output rating exceeds the connected loads’ actual power draw (i.e. the
inverter is rated at 5 kW but all loads amount to 3 kW of maximum instantaneous power draw),
SimpliPhi still
expects that the proper additional precautions be made to ensure that the PHI Battery bank is not over-
discharged. This typically involves the installation of an additional overcurrent protection device between the PHI
Battery bank and the inverter to ensure that the PHI Battery bank does not discharge beyond its maximum
instantaneous power rating. Failure to do so will destroy the PHI batteries and Void the Warranty.
ℎ
=
(
)
×
(
ℎ
)
Example: Two PHI 3.8 kWh-51.2V
nominal
batteries must be installed with an additional 75 ADC-rated breaker
between the battery bank and the inverter.
(
ℎ
)
= 2 × 37.5 = 75
Minimum Battery Quantity per inverter calculation results are listed below. When using more than one inverter in a
system, PHI Battery bank sizing is more precise when the calculations described above are used instead of the following
tables.
48V Sizing for Maximum Instantaneous Discharge (Load Rate)
Only 51.2V
nominal
PHI Batteries can be paired with 48V-rated OutBack equipment.
48V Inverter Model
Inverter Power
Rating (kW AC)
Inverter
Efficiency
Load
Rate (kW
DC)
PHI 3.8-51.2V
nom
MIN Battery Quantity
PHI 2.9-51.2V
nom
MIN Battery Quantity
OutBack Radian 8048A 8 93% 8.6 5 6
OutBack Radian 4048A 4 93% 4.3 3 3
OutBack SkyBox 5 97% 5.2 3 4
OutBack VFXR 3648A 3.6 93% 3.9 3 3
OutBack FXR 3048A 3 93% 3.2 2 3
24V Sizing for Maximum Instantaneous Discharge (Load Rate)
Only 25.6V
nominal
PHI Batteries can be paired with 24V-rated OutBack equipment.
24V Inverter Model
Inverter
Power
Rating
(kW AC)
Inverter
Efficiency
Load
Rate (kW
DC)
PHI 3.8 -
25.6V
nom
MIN Battery
Quantity
PHI 2.9 -
25.6V
nom
MIN Battery
Quantity
PHI 1.4 -
25.6V
nom
MIN Battery
Quantity
PHI 730 -
25.6V
nom
MIN Battery
Quantity
OutBack VFXR 3524A
3.5
92%
3.8
4 4 6 11
OutBack FXR 2524A
2.5
92%
2.7
3
3
4
8
12V Sizing for Maximum Instantaneous Discharge (Load Rate)
Only 12.8V
nominal
PHI Batteries can be paired with 12V-rated OutBack equipment.