The EIS-BM part helps to prevent battery failures that can occur when the audio system is used for an extended period while the vehicle is off. Part EIS-BM will connect in line with the power going to audio, video or game systems to monitor any vehicles battery voltage level when the vehicle ignition is off. The EIS-BM will automatically turn that device off when the vehicles battery voltage drops below 11.5 volts for four seconds or more. With the addition of a high-amperage relay (not included) EIS-BM can also be used to monitor the voltage in a multi-battery system and alternate charging between primary and secondary batteries.



