Sealey bt2012 digital battery and alternator tester with printer 12v sealey bt2012 p this 12v battery tester from sealey provides a fast accurate diagnosis of battery and alternator faults with facility to print the results a large lcd display shows charging and starting system status and returns decision making information in seconds results need no interpretation and the tester will work on batteries with as little as 7 6v of residual charge p p test ranges br 100 800 cca din br