What is Power Fade?
Power Fade, part of the BMS, is a proprietary system DesignLine has put in place to protect the batteries from being deeply discharged, causing life reduction. It involves the VMS monitoring the battery SOC. Should SOC drop below predefined levels, it will progressively reduce the power systems available on the bus to preserve SOC. Power Fade starts with non-critical loads, such as Air Conditioning and entertainment systems. If this is still not sufficient to allow for adequate APU recharging, Power Fade will progressively reduce the power output from the drive system until the bus is in a limp home mode, with only a very low level of power available. The DesignLine Power Fade system is performed over a long time period. Once initiated, the driver is advised and has sufficient time to respond correctly. The Power Fade system is in place largely to prevent the driver from ignoring the alarms and permanently damaging the battery pack.
