New Battery Powered Grease Gun features:

• Develops 6,500 psi
  
• 3-way loading - 14 oz. cartridge
  
• 3' flexible hose extension
  
• 5.25 oz. / min @1,000 psi delivery stroke
  
• Includes 120v charger and 1 or 2 12v batteries
  

One fully charged battery delivers up to 6 cartridges of grease
http://www.maintenanceproductsdirect.com/Products_Grease_Guns/ALE-575.htm