DEMO Unit - was used for photos and got scratched up a bit but has never been used. 
 
 
48 Volts DC | 100 Amps | 4.8 KW
 
When wind or solar power is not available, or you need to take batteries offline, this DC generator/alternator can be part of your power backup solution.  
 
ALTERNATOR FEATURES
 
• Internal Voltage Regulator (adjustable voltage)
• 7/8" Key shaft
• No brushes, no brush springs
• One moving part, no moving electrical parts
• One-piece bearing housing
• Permanent bearing alignment 
• Oversize lubrication reservoir
• Gass Filled TFE Fluorocarbon steal (Teflon)
• Air-cooled 7.3" diameter advanced desgin 

ALTERNATOR BENEFITS 
 
• Strong, compact reliable power
• Exceptional bearing life
• Simple inspection and maintenance procedures
• Bi-directional rotation
 
What size engine is needed to use this?
When you convert power from one form to another, there is always some loss in the process. Where does this power go? The loss comes from the heat generated by combustion and friction of the engine.   An alternator or generator is only 80- 90% efficient. When deciding what size motor or engine will drive your alternator or generator, you should consider the loss in your calculations.
 
Horse Power
Horsepower is a unit of measurement of power.
 
1 HP is approximately equivalent to 746 watts, below.
 
• 1 kW = 1.34102 HP
• 2 kW = 2.68204 HP
• 3 kW = 4.02307 HP
• 4 kW = 5.36409 HP
• 5 kW = 6.70511 HP
• 6 kW = 8.04613 HP
• 7 kW = 9.38715 HP
• 8 kW = 10.7282 HP
• 9 kW = 12.0692 HP
• 10 kW = 13.4102 HP