Renewable Energy; Battery Bank - Outback FX Series Installation Manual

Planning

Renewable Energy

The inverter cannot connect directly to PV, alternators, or other DC sources. The batteries are the
inverter's primary source of power. However, if the DC sources are used to charge the batteries, the
inverter can use their energy by drawing it from the batteries.
A renewable source is always treated as a battery charger, even if all of its power is used immediately.
The renewable source must have a charge controller, or some other regulation method, to prevent
overcharging. OutBack Power's FLEXmax family of charge controllers can be used for this purpose, as
can other products.

Battery Bank

When planning a battery bank, consider the following:
 Cables: Recommendations for battery cable size and length are shown on page 18. The maximum length will
determine the placement of the battery bank. Local codes or regulations may apply and will take priority over
OutBack recommendations.
 Battery Type: The FX inverter/charger uses a three-stage charge cycle.
~ The cycle was designed for lead-chemistry batteries intended for deep discharge. These include batteries for RV, marine,
golf-cart, and forklift applications. They also include gel-cell batteries and absorbed glass-mat (AGM) batteries. OutBack
Power recommends the use of batteries designed specifically for renewable energy applications. Automotive batteries
are strongly discouraged and will have a short life if used in inverter applications.
~ Lithium-based batteries and other advanced battery technologies may require special considerations. Please contact
OutBack Technical Support at +1.360.618.4363 before implanting advanced technologies.
 Nominal Voltage: These inverters are designed to work with specific battery bank voltages, which are different
depending on inverter model. Before constructing a battery bank, check the inverter model and confirm
nominal battery voltage.
 Charger Settings and Maintenance: A vented battery enclosure may be required by electric code and is
usually recommended for safety reasons. It may be necessary to use a fan to ventilate the battery enclosure.
Batteries must be regularly maintained according to the instructions of the battery manufacturer.
 Bank Size: Battery bank capacity is measured in amp-hours. Determine the required bank specifications as
accurately as possible, beginning with the items below. This avoids underperformance or wasted capacity.
These ten items are obtainable in different places, summarized in Table 2 on the next page. Some of the
information is specific to the site or application. Some can be obtained from the battery manufacturer.
Information on OutBack products is available from OutBack Power Technologies or its dealers.
A. Size of load:
B. Daily hours of use:
C. Days of autonomy:
D. Application: This often helps define or prioritize the previous three items. Off-grid systems often require enough
capacity to last for an extended period before recharging. Grid-connected systems frequently need only enough
capacity for short-term backup during outages.
10
IMPORTANT:
Battery charger settings need to be correct for a given battery type. Always follow
battery manufacturer recommendations. Making incorrect settings, or leaving them at
factory default settings, may cause the batteries to be undercharged or overcharged.
CAUTION: Hazard to Equipment
Batteries can emit vapors which are corrosive over long periods of time. Installing
the inverter in the battery compartment may cause corrosion which is not covered
by the product warranty. (Sealed batteries may be an exception.)
These are the most basic and
essential factors used to
determine bank size.
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