The NRG Symphonie iPack charger is used to charge the battery in Symphonie iPacks before field installation. The charger is a wall mount power supply that includes 4 different plugs compatible with most wall socket types found around the world. The charger’s intelligent charge controller allows the iPack to remain plugged in indefinitely without damaging the iPack or the charger. All lead acid batteries will lose their capacity over time. If the iPack battery remains at low capacity for an extended period of time, the battery will no longer accept or maintain a charge. Therefore, the battery must be recharged if an iPack is kept in storage or is unused for any period of time.