BVM300(System of 31 BVM units) which is a 0~5VDC and 0~20VDC 1mv resolution .1% accuracy daisy chained 31 channel voltage datalogger. This integrates with the Torkel controller to give cell by cell voltage measurement. This means if the battery string fails a load test the individual battery that is the culprit can be easily identified. These two instruments combineed together meet the test standards IEEE450, IEC896-1, IEEE 1188-1996 & IEC896-2.