To determine if either of the popular Battery Minder devices provided any benefit in restoring sulfated batteries, a series of tests were performed on Eclipse 500 batteries manufactured by Enersys. Battery Minder units 244CEC1-AA-S3 and 24041-AA-S3 were used for the tests.
For these tests to determine if Battery Minder has any effect in reducing internal resistance (increasing capacity), 4 marginal performance batteries were selected for testing.
For the first test, 2 batteries would be used. Battery voltage and internal resistance were measured each day. Initial testing lasted 21 days with daily measurements taken with specialized calibrated equipment. The results of those tests are recorded in the Tables below.
The results from testing on battery A031 indicate no reduction in battery internal resistance after 21 days of Battery Minder 244CEC1-AA-S3 use.
The results from testing on battery A017 also indicate no reduction in battery internal resistance after 21 days of Battery Minder 24041-AA-S3 use.
Examining the measured battery internal resistance over the 21 day testing period, the data demonstrates that the Battery Minder delivered no measurable reduction in battery internal resistance.
As the battery's internal resistance is the key to battery capacity, this test demonstrated that the Battery Minder product delivered no benefit over a 21 day period.
After the 21 day Battery Minder charging/conditioning period, a battery capacity check was performed on each battery per the Eclipse 500/550 Aircraft Maintenance Manual. The results of the post-Battery Minder capacity check were nearly identical to the pre-Battery Minder capacity tests, and the batteries did not meet the requirements for return to service.
To validate the results from the testing on the first two batteries, a second set of tests were performed on two additional batteries. The same equipment and conditions used in the first two tests were used on the validation tests. As this was a validation test only, readings were only taken every other day and the test was only conducted for 18 days.
As with the previous test, no reduction in internal resistance was noted. Similarly, the 2 validation batteries also failed post-Battery Minder capacity checks.
These tests validate the widely held view of battery industry professionals that once sulfating has set in (hard sulfation), it cannot be reversed and the only option is to replace the affected battery.