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I received a report of a battery failure from alleged overcharging.  The battery was swollen and disfigured from an appearant overcharge situation created by the battery charger.  In this case a simple Victron Energy Blue Power waterproof model was used and was rated at 12 volt/15 amps.  The battery was an Energy1 battery of type AGM and group 31 spec.  Attached to the system was a Nanopulser Battery Conditioner.  Initial voltage test of the system showed 14.6VDC at begining of the charge cycle.  Providing 13.3 amps of charge.  End of day check after 8 hours of charge showed 13.6 VDC and .3 amps.  At some point in the cycle the battery vented and the smell of Hydrocloric Acid was overwhelming.  The system was shutdown for safety reasons.

First received was the Bluepower charger.  This unit will be set up for testing on a known good battery.  Terminal voltages will be checked as the charger goes through the charge cycle and recorded.  Report stats wil be provided upon completion.

Once the system was connected readings were taken and battery static voltage was 12.88 VDC.  The voltage at the battery after the charger was connected was 12.87 VDC.   The check after 1 hour was the same at 12.87 VDC.   After the 4 hour check voltage output remained at 12.87 VDC.

 Next Day-Removed charger and connected the new charger to the same battery.  On connection the charge voltage went to 14.82 VDC.   The 1 hour check showed the charge voltage at 13.7 VDC.  this charger is acting in accordance with the specs at this point. At the 2 hour check the voltage output was 13.71 VDC.   5 hours into the test the charger was sitting at 13.7 VDC.   At the end of an 8 hour cycle the charge voltage was still 13.7 VDC.

The next morning the battery charger was reconnected and the results were the same as the day before.

Finally some presumptions:
The original charger had gone bad and provided no charge at all.  The replacement charger acted as it should.  When the battery was returned with the system it was totally discharged.  After many hours on a trickle charge the battery displayed a terminal voltage of 12.0 VDC.  It is believed that light sulfation had occured at this point.  When the battery was connected to a standard charge cycle the sulfation flaked off the plate and caused a dead short between the plates.  Seeing the short as a load, the charger went into absorbtion mode and consequently the battery totally failed.

The charger was returned to the customer with a new battery and no further issues have been reported.