Prolong Battery Discharger Operating Instructions 

The Prolong Battery Discharger is very simple to use.  For best results, follow these easy instructions:

1) Charge the hybrid battery with your Prolong Battery Charger until the battery voltage levels off & stops rising, then for an additional 4-6 hours.
2) Disconnect the Prolong Battery Charger from the vehicle car harness and connect the Prolong Battery Discharger.
3) Plug the Prolong Battery Discharger into AC power and power it on.
4) Press the button for the desired discharge termination voltage.  (Be sure to fully charge the pack between each discharge cycle).

The Prolong Battery Discharger will display a solid red LED for the termination voltage selected and begin the discharge process, safely draining the battery until the discharge termination voltage is reached.  The amp meter will display the current being drawn from the battery during the discharge process.  When the discharge is complete the LED will flash red for seven minutes as the discharger system cools itself down.  Once the cool down is finished, the idle LED will come on and the alert buzzer will sound.  NOTE: The battery voltage will ‘rebound’ or rise after the discharge process is complete.  This is normal and should be expected.

5) After the discharge is complete, reconnect your Prolong Battery Charger and charge the battery again until the voltage levels off and stops rising.  We recommend allowing the Prolong Battery Charger to run for 4-6 hours after the voltage stops rising to top balance the battery cells.

Discharge Termination Voltage Table:

Recommended vehicle specific discharge termination voltage:

Single Cell 99-03 Prius 04-15 Prius 06-15 Camry Hybrid 12-20 PriusC (Aqua)

00-06 Insight

03-05 Civic Hybrid

05-07 Accord Hybrid

06-11 Civic Hybrid 06-13 Highlander Hybrid

Chevy Silverado/ Tahoe Hybrid

Lexus RX/
GS Hybrids

Number of cells in battery pack One 228 168 204 120 132 240
First Discharge 0.8V 182V 134V 163V 96V 105V 192V
Second Discharge 0.6V 137V 101V 123V 72V 79V 144V
Third Discharge 0.5V 114V 84V 102V 60V 66V 120V


Turn buzzer on and off:

While the Prolong Discharger is in idle mode hold the stop/reset button for five seconds.

Technical Specifications

Maximum ambient temperature: 100 degrees Fahrenheit (38 degrees Celsius)

AC INPUT: 88-264VAC; 47-63Hz
0-360VDC, 1.5A (depending on version)

1: 12VDC, 2.9A
2: 0-540 W

Prolong Battery Charger User Guide