Xantrex Prosine PS2.5 Installation And Operation Manual

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Xantrex Prosine PS2.5 Installation And Operation Manual Manual pdf 86 page image

Prosine 2.5/3.0 Installation & Operation Guide 69Section 7: BatteriesSealed Gel CellAnother type of deep-cycle battery construction is the sealed gel-cell. They donít use removablebattery caps. The electrolyte is in the form of a gel rather than a liquid. The sealed construction allowsthe batteries to be mounted in any position without spilling. The advantages are no maintenance (tothe battery itselfóthe system will still require routine maintenance), long life (800 cycles claimed)and low self-discharge. The disadvantages are high initial cost and the possibility of damage fromovercharging.While there are many manufacturers of quality flooded batteries, there are only a few manufacturersof suitable gel-cells. Donít confuse gel batteries with maintenance free batteries. The latter is typicallya standard liquid electrolyte type battery without caps for adding water, and if the electrolyte gets low,you replace the battery.AGM (absorbed glass mat) batteries are similar to gel-cells and deep-cycle types may be used ininverter applications.EnvironmentFor long life and good performance, batteries need to be located in protected, ventilated enclosureinsulated from extremes in temperature.LocationBatteries should be located in an accessible location with access to the battery caps and terminals. Atleast six inches of clearance above is recommended. They must be located as close as possible to theinverter, but can not limit the access to the inverter and the inverterís over-current protection device.Do not locate the inverter in the same space as the batteries, unless the batteries are of the sealed gel-cell type.EnclosuresBatteries must be protected inside a ventilated enclosure. The enclosure should be ventilated to theoutdoors from the highest point to prevent accumulation of hydrogen gasses released in the chargingprocess. An air intake should also be provided at a low point in the enclosure to allow air to enter theenclosure to promote good ventilation.TemperatureThe effective capacity of a battery is reduced when cold. This phenomenon is more significant withlead-acid type batteries compared to alkaline types. When the internal temperature of a lead-acidbattery is 32°F (0°C) the capacity can be reduced by as much as 50%. This effectively reduces the sizeof the systemís ìgas tankî, requiring more frequent ìrefuelingî by the charger. This should beconsidered when designing the system. If extremely cold temperatures are expected at the location ofa system, a heated equipment room should be considered.If the system is located in an unheated space, an insulated enclosure is highly recommended for thebatteries. During the charging process, the batteries release heat due to the internal resistance of thebattery. If the batteries are insulated, the heat can be kept in the batteries to keep them warmer. Thiswill substantially increase the performance of the system.