Magnum Energy Integration Guide

REV070219
SimpliPhi Power, Inc. | 3100 Camino Del Sol | Oxnard, CA 93030, USA | [phone] | [e-mail] | SimpliPhiPower.com
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3.1 – Discharge Calculation: Inverter Power Bank Sizing
To optimize the PHI battery bank and protect against over-discharge and voiding the battery Warranty,
the PHI battery bank should be sized at least double (2x) the kW rating of the inverter.
Discharge Example A
This example uses the following calculation:
B
#Inv
≥ Inv
kW
/ Bat
kW
This example assumes the following:
• Inverter is rated at 4.4 kW
• PHI 3.8 48V battery has a load rating of 1.92 kW (37.5 Amps DC x 51.2 Volts nominal)
The calculation and assumptions correspond to:
B
#Inv
≥ 4.4 kW / 1.92 kW = 2.29
So, a properly sized PHI battery bank based on maximum discharge of the inverter would have a
minimum of 3 batteries.
Discharge Example B
This example uses the following calculation:
B
#Inv
≥ Inv
kW
/ Bat
kW
This example assumes the following:
• Inverter is rated at 4 kW
• PHI 3.8 24V battery has a load rating of 1.15 kW (45 Amps DC x 25.6 Volts nominal)
B
#Inv
≥ 4 kW / 1.15 kW = 3.48
In this example, a properly sized PHI battery bank based on maximum discharge of the inverter
has a minimum of 4 batteries. This ensures no greater than C/2 battery load.
If the PHI battery bank includes fewer batteries than calculated, either:
A) Install additional over-current protection between the battery bank and the inverter to prevent the
batteries’ over-discharge.
B) Configure the inverter’s Auto Generator Start device settings for the generator to power the loads
when loads’ draw exceeds the PHI battery bank’s maximum continuous discharge rating. These
settings are described in more detail in the following sections of this Integration Guide.