REV070219
SimpliPhi Power, Inc. | 3100 Camino Del Sol | Oxnard, CA 93023, USA | (805) 640-6700 | [email protected] |
SimpliPhiPower.com
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2.1
– Discharge Calculation: Inverter Power Bank Sizing
To optimize the PHI Battery bank and protect against over-discharge (voiding the battery Warranty), the
PHI Battery bank should be sized at least double (2x) the kW rating of the inverter.
Discharge Example: B
#Inv
≥ Inv
kW
/ Bat
kWh
•
Inverter is rated at 8 kW
•
PHI Battery is rated at 3.8 kWh, therefore the C/2 load rating is 1.9 kW
B
#Inv
≥ 8 kW / 1.9 kW = 4.21
A properly sized PHI Battery bank based on maximum discharge would have a minimum of 5 PHI
Batteries.
This ensures no greater than C/2 battery load. If the PHI Battery bank has fewer batteries than
calculated, special care must be taken with the inverter settings to limit the load below the specified rating
of the PHI Battery. These settings are described in the following sections of this Integration Guide.
2.2
– Charge Calculation: Charge Controller Power Sizing
To optimize solar harvesting, a properly sized PHI Battery bank should be able to accept the maximum
PV charge current. To determine the minimum number of PHI Batteries required to optimize PV, divide
the output of the
charge controller(s) by the “max continuous charge current” per PHI Battery. Be sure to
verify the “max continuous charge current” for the PHI Battery model that you’re using, because it may
differ from C/2 depending on the model.
Charge Example: B
#PV
≥ I
PVChrgMax
/ I
BatChrgMax
•
Maximum continuous charge current for PHI 3.8 kWh 48V = 37.5A
•
PV charge controller max = 80A
B
#PV
≥ 80A/37.5A = 2.13
A properly sized PHI Battery bank based on available PV charge would have a minimum of 3 PHI
Batteries.
This maximizes the use of available PV while ensuring the PHI Batteries are never stressed by
overcharging. If the PHI Battery bank has fewer batteries than calculated, special care must be taken with
the inverter settings to limit the charge rate below the specified rating of the PHI Battery. These settings
are described in the following sections of this Integration Guide.
In summary: When comparing the same system using these two calculations for sizing the PHI
Battery bank, the minimum number of PHI Batteries should be the greater of the two results
(Discharge Calculation & Charge Calculation). In this example, this translates into 5 PHI Batteries
in the system.
3.0
– Victron BMV-700 Installation & Setup
The BMV-7xx series products will follow the general installation and settings in this section. The BMV-700
is used as a specific example here. Other products in this series have additional capabilities (i.e., the
BMV-702 has the capability to monitor an additional PHI Battery).
The BMV-
700 is a precision battery monitor that functions as a ‘fuel gauge’ and indicates time remaining
in the PHI Battery bank. The remaining PHI Battery capacity depends on the ampere-hours consumed,
discharge current, temperature and the age of the PHI Battery. Ampere hours consumed are calculated
by integrating the current flowing in or out of the PHI Battery. Complex software algorithms are utilized to
take all these variables into account for an accurate reading. The monitor tracks several parameters
regarding the state of charge of the PHI Battery which can be used to evaluate usage patterns and
battery health.
