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### Topic: Power Consumption (Read 495 times)previous topic - next topic

#### AbhayHM

##### Oct 24, 2018, 07:09 am
I have 3 micro controllers of power ratings 5v 40mA, 5v 20mA and 5v 50mA i have a battery of power rating 12v 2.5Ah , if i use dc to dc 12v to 5v converter to power up all the three micro controllers, how long will the battery last?

#### Grumpy_Mike

#1
##### Oct 24, 2018, 08:41 am
Add up all the currents 40+20+50= 110 mA
So in theory with a 2.5Ah source you will get 2.5 / 0.11 = 22.7 hours.
But in practice you are only likely to get half of that.

You can get more battery life if you use a switching converter sometimes called a buck regulator to convert the voltage.

#### mauried

#2
##### Oct 24, 2018, 08:43 am
Around 50 hours , assuming 90% efficiency for the buck converter.
Battery is 12V 2.5 AH.

#### AbhayHM

#3
##### Oct 24, 2018, 09:02 am
Thank you so much!

#### MarkT

#4
##### Oct 24, 2018, 12:55 pm
If you let the battery over-discharge, even briefly, its capacity will drop dramatically, note.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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