Outback Power Systems FLEXpower ONE One Fully Pre-Wired Single Inverter System Installation Manual - Manual (Page 55)

Specifications
900-0095-01-00 Rev A
53
Renewable Energy Input & Storage
PV Sizing
Single charge control systems can support photovoltaic arrays with the following specifications. Dual
charge controller systems can handle 2 arrays with the following specifications.
Maximum Array Size
 4,000 W
STC
on 48 Vdc system, 2,000 W
STC
on 24dc system
 145 Vdc (150 V
OC
including local temperature correction factor per NEC 690.7)
 64 A I
SC
maximum PV array current per NEC 690.8
A PV string-sizing tool is available on the following website link:
 http://outbackpower.com/resources/string_sizing_tool/
Battery Bank Sizing
In general, the size of the loads (watts) and the required backup period (hours) will determine best size
(amp-hour capacity) for the battery bank.
Running Time and Size
The battery bank’s size determines the length of time the inverter can supply AC output power. The
larger the bank, the longer the inverter can run and the longer the recharge time.
Depth-of-Discharge
The battery bank should be designed so the batteries do not discharge more than 50-60% of their
capacity on a regular basis. Discharging up to 80% is acceptable on a limited basis, such as a
prolonged utility outage. Totally discharging a battery can reduce its effective life or permanently
damage it. Consult the battery manufacturer for specific depth-of-discharge recommendations.
Days of Autonomy
Days of autonomy may vary depending upon the availability of the charging source(s), the critical
nature of the load and other factors. If the system is to be powered by renewable energy sources such
as solar, determine the appropriate number of days of autonomy by allowing for cloudy weather as
well as other seasonal variations in available energy.
Back up power systems which use utility power for recharging should use the estimated number of
days of maximum power outage for determining days of autonomy.
Amp-Hour Requirements
Amp-hour requirements will vary with each installation depending on the loads that are connected
and the desired amount of time for those loads to be supported in the event that utility power is
unavailable
Amp-hour Capacity
Deep cycle batteries have a capacity measured in amp-hours. Amp-hours are a measure of current
flow over time. An amp-hour figure is derived by multiplying current (amperes) by the amount of time
the current flows (hours). This applies equally to the amount you take out of a battery (discharging) or
the amount you put into it (charging).