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abchopra2010
10-15-2008, 11:41 PM
I have a circuit in which i have 4 motors of 12v 40W and 1 motor of 12V 180 W. I dont know what kind of battery is needed to power this. How much ampere is needed for these battery. Please Help!

anilmaddala
10-16-2008, 06:51 PM
As far as i know, you can calculate the required current, when you know the power and current, from this
P=V*I
so for 12V 40W I=3.33a amp
for 12V 180W I=15amp

So for four 40W and one 180W total current required is I=4*(3.334)+15
=28.33 amps

So basically you can use a 12v lead acid battery, but for the ampere rating,
if you have a 30 amps battery, you can run it around 1hr, go for 60 amps - 2hrs and so on. Based on the current rating, the duration you can use without charging can be determined.
Mind this, it is not exact but approx

allbits
10-17-2008, 01:19 PM
That a huge motor!!
whats your application?

If you are sure thats the motor you want, and you want to run it in battery, you might have to use a battery PACK. How long do you want to run the motors, and what load are you planning to give?