I wanted to calculate total allowed number of cranks until the starter not enough current to crank or battery dead. My battery capacity is 35Ah. Assume the power of the starter is 800W.
Assume fully charged battery : 12.6V
Calculation : P = VI
800W = (12.6V)(I)
I = 63.5A
so,
35Ah/63.5A = 0.55h
0.55h x 60 = 33minutes
33minutes x 60 = 1984seconds
If assume 5seconds for each crank, 1984seconds/5seconds = 396 times
According to calculation, the starter can be cranked for 396 times until battery is dead, nearly impossible. As I've heard, the starter can only be cranked 15-20 times maximum before the starter not enough current to crank or battery dead.
Is there anything wrong with my calculation ?
I can see that the voltage drops with every starter motor cranking. The current will increase if the voltage drops, I understand this concept. Using this concept, how I could calculate total number of times can be cranked ?
Kindly note : I'm doing a project on engine start/stop system during traffic light stop. Thats why I'm calculating the total number of times can be cranked. Please give your suggestions. TQ.
Assume fully charged battery : 12.6V
Calculation : P = VI
800W = (12.6V)(I)
I = 63.5A
so,
35Ah/63.5A = 0.55h
0.55h x 60 = 33minutes
33minutes x 60 = 1984seconds
If assume 5seconds for each crank, 1984seconds/5seconds = 396 times
According to calculation, the starter can be cranked for 396 times until battery is dead, nearly impossible. As I've heard, the starter can only be cranked 15-20 times maximum before the starter not enough current to crank or battery dead.
Is there anything wrong with my calculation ?
I can see that the voltage drops with every starter motor cranking. The current will increase if the voltage drops, I understand this concept. Using this concept, how I could calculate total number of times can be cranked ?
Kindly note : I'm doing a project on engine start/stop system during traffic light stop. Thats why I'm calculating the total number of times can be cranked. Please give your suggestions. TQ.