The M3528 series of chargers is a voltage limited current source used to charge higher voltage batteries, ultracapacitor or double layer capacitor energy storage strings. Variable frequency drive systems can require energy storage to back up power for mission critical or continuous processes. Any system requiring energy during a complete loss of input power need some type of energy storage device. These systems use batteries and ultracapacitors in strings with high voltage ranges at higher power ratings. Standard chargers typically do not have this voltage range, and are intended for use with batteries only. The M3528 Charger Module can charge battery or ultracapacitor strings from 200-600VDC.