Model 3328 50 amp

Patent Pending

GPU Starting Unit Model 3328 50 amp
  • GPU Starting Unit Model 3328 50 amp
  • GPU Starting Unit Model 3328 50 amp
  • GPU Starting Unit Model 3328 50 amp

The 3328 is a full 28.5 Volt unit that will give faster, cooler starts on all turbine engines. The 50 Amp power supply is large enough to power various systems such as inverters, avionics and GPS. Always recharge after use until the green charger light appears. Once charged, leave the unit plugged in. Avoid fully discharging the batteries as damage to the cells may result.

The Model 3328 GPU is a combination power supply and battery pack.


  • 52 Amp hours @ a 10 Amp rate
  • 28.5 Volt DC; 30.5 Volts at rest
  • 2800 Amps peak current

Power supply/charger

  • AC Input: 110 Volts OR 220 Volts (specify)
  • 50 Amps DC continuous output @ 28.5 V
  • Battery recharge time: 6 hours


  • L 38” x W 21” x H 20”/ 97cm x 53cm x 51cm
  • Handle height: 48”/ 122cm
  • 241 Lbs./ 109.31 Kilos complete

When operating the continuous power supply unplug the battery disconnect. Although this unit is equipped with 28.5 Volt batteries, it will actually read 30.5 Volts at rest. Leaving the disconnect connected will deplete the batteries nearly 50% before their voltage reaches 28.5 Volts. Thus, only one-half of the battery capacity will be available for engine starting. By keeping the batteries separated from the continuous power supply, you will have full battery capacity for engine starts. If you need more than 50 continuous amps, using the battery disconnect will enable the batteries to make up for any amperage needed.

There are approximately thirty 110 volt and thirty 220 volt NEMA plugs in use. Also, customers have various receptacle at their hangars and MRO facilities and may require specific AC cord length to meet their requirements. Due to these facts, we do not automatically provide AC power cords. If you provide the NEMA plug number and specify the AC power cord length you require we will build a cord to be shipped with your unit for a small fee.


For technical assistance, contact Jim Wurth, chief engineer, directly at (928) 231-4536 or at


All Start Pac™ products come with a 1-year warranty on workmanship and materials. Batteries are cycle-dependent and therefore are not covered under this warranty.

Please handle this unit in a responsible manner. Start Pac™ is not responsible for damages caused by misuse or neglect.