How much horsepower is your alternator using?
Using Ohms Law: The formula to find power (watts) using Ohms Law is P = I X E or Power = Current X Voltage I = 50 amps (alternator rating) E = 14.9 volts (set voltage of alternator when engine is running) 50 amps X 14.9 volts = 745 watts
Assuming 1 horsepower is equal to 746 watts, we can calculate lost horsepower as follows: HP=745 watts / 746 watts HP=1.0 (approx.)
The amount of power it takes to drive a 50 amp CVR Propower Alternator to its full rated power is approximately 1.0 HP. Which means if your batteries are fully charged and in good condition, your alternator will not have to work that hard, will pull only fractional horsepower on demand, and will produce enough at idle speed where it does not matter if horsepower is drawn.
Caution: Always use good fully charged deep cycle batteries. Your alternator is designed to maintain your battery not be a battery charger. Never install an alternator on a battery that is not fully charged.
Tech Tip: We do not recommend switching one wire alternators off/on while the engine is running. This causes severe internal spikes in the alternator which will cause damage.
Tech Tip: Never disconnect the battery when the engine is running to see if the alternator is charging. Excessive load or voltage spikes on alternator will damage internal components or any on-board computers in the vehicle. Always use a multi-meter.
Sizing Up Your Alternator
Accessories Amp Draw
|Trans Brake||10 – 20|
|Throttle Stop||5 – 18|
|On Board Computer||0.2 – 0.3|
|Electric Fans||5 – 18|
|CDI Ignition||5 – 30|
|HEI Ignition||5 – 10|
|Nitrous Solenoid (each)||5 – 15|
|Electric Fuel Pumps||3 – 9|
|Electric Water Pumps||5 – 12|
|Instrument Panel||1.5 – 3|
|Brake Lamps||3 – 5|
|Running Lights||3 – 5|
Charging Cable Gauge Size
|Amps||Up to 4′||4′-7′||7′-10′||10′-13′||13′-16′||16′-19′||19′-22′||22′-28′|