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Old 02-25-2020, 01:02 PM   #12
katy
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Location: Red Deer, Alberta
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Default Re: I wish I would have waited

Quote:
Originally Posted by 30 Closed Cab PU View Post
Correct the below if I am wrong.


The math


Assume the starter draws 40 amps at 6 volts (probably not correct but used for comparison of 6v vs. 12v)


6V: R (Resistance) = Volts (E)/Current (I), 6/40 = .15 ohms
W (Power Watts) = I x E, 6 x 40 = 240 Watts


12V: R does not change, same starter as above = .15 ohms
I = E/R, 12/.15 = 80 amps
P = I x E, 80 x 12 = 960 Watts


So when going from 6 Volts to 12 volts using the same starter, Current doubles and Power quadruples


Running a 6 V starter under load continuously like a motor at 12 Volts would destroy the starter . Since it is only used intermittently for a few seconds, it does not heat up dangerously and is allowed to cool off even at 12 Volts.
You got it!!
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