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I need a help for power recommendation


#1

I need a help for power recommendation.
I want use FEZ Cerb40 II to control a RF module.
The RF module need 5V input and the peak Current Consumption is 600mA.
Any recommendation for my purpose?
I think some approaches.

  1. 3*AAA battery + lm1577 step-Up Voltage Regulator to output 5V.
  2. Li-iON (Li-ion) or (Li-Polymer)+ lm1577 step-Up Voltage Regulator to output 5V.
  3. What battery has lowest Self-discharge? I hope the battery can work maybe put 3 years.

Please give me any advice, thank you very much.


#2

I’d actually ask are you sure that the RF device needs 5v, or will it work down to say 3.2v with a single cell Li-ion battery.

Self discharge. Are you saying that you need to run for 3 years without charging? You haven’t said how you’ll need it so a scenario like switching it off for 30 minutes at a time, on for 4 secs, off again, will give a small consumption and therefore make a difference in how large a battery you need. Without really understanding what the power loads over time are, we may not be able to give you relatively useful advice.


#3

YES, this RF device needs 5v, peak current 600mA.
My application is an event alarm system. I design a Mechanical mechanism for power switch(such as Vibration switch), so the system is power off usually. When the event happened, the Mechanical mechanism force the power switch to switch on the power to power the system.
The event may not happens for 1-2years. So the battery should live for long time.
The MCU+RFModule + battery need to be embedded in a diameter 3.5*20 cm PVC tube, so the size is also important.

Thanks


#4

It sounds like their is some interesting stuff to showcase here Tzu. What are you messing with? Where is the PVC tube going?


#5

Sorry, before it published, I can’t tell more detail. It is a real engineering application.
I will show here if this project get success.

Thanks


#6

Alkaline has a discharge 2-3% / year, Lithium can go to 2-3% month and NiCad even more. Another factor which is important for battery choice is the operating temp, bellow 0 or above 40C makes very great differences.