The Act meter algorithm used for calculating the AH Capacity of lead acid batteries is not valid for all designs and brands of batteries and the true way of testing a battery for Ah capacity is to run a proper load test. Whilst Power Sonic does not endorse the meter, this app will make adjustments to the Act algorithm and final reading to help provide a more accurate result for Power Sonic batteries. Some hand held portable battery testers claim to use specific battery characteristics and algorithms to determine ‘Absolute Ah Capacities’ within a few seconds. In fact, testers that claim to measure Ah capacity across different brands of batteries may create more problems than they resolve. Fire and security alarm installers be aware! False or inaccurate readings can indicate a battery is at the end of its service life when its service life may have actually only just begun.