Available now: View & Order

The Prolong™ Battery Module Load Tester enables quick & easy load testing of each module in a hybrid battery pack.  It uses any standard automobile H4 headlight bulb.  By easily and reliably identifying failed modules for replacement, a better battery rebuild can be performed, with significant reduction in the likelihood of another post-rebuild cell failure.


How to use Load Tester to identify failed modules:

1) Install any H4 automobile headlight bulb into the load tester
2) Connect load tester to a single module as shown in the image above
3) Record voltage before starting test
4) Turn load tester on for exactly 120 seconds
5) Just before turning load tester off at 120 seconds, record the module voltage
6) Calculate the drop in voltage by comparing starting and ending voltage values

The modules that display a significant voltage drop when compared to the rest of the pack should be replaced.  This can easily be done with a pencil & paper, or with a computer spreadsheet.  Here is an example of a 2007 Prius after module load testing:


Here is another example provided by one of our customers when testing after each discharge cycle: