Li-ION Battery selection

[Bjtpower_magic]

Hi Everyone,

I have microcontroller circuits and requirement is "Circuit shall give 0.5 hour of Back up Time''

Microcontroller and its around circuitry (Opamp, i2c chip, EEPROM, Optocoupler ic, SPI Communications, SDCard and SRAM) consumes 0.7A and all are powered with 3.3V.

Can you help me for selecting Li-ion battery selection of capacity (Ampere hours)

Marx

 

[KlausST]

Hi.

Ampere x hours = amperhours.
I'm sure you can do this math on your own.
**********

May I ask what consumes 0.7A ?
...similar applications maybe draw 35mA.

Klaus

 

[Bjtpower_magic]

Hi Klaus,

In my application, we have certain sections which consumes 700mA at worst case.

so 700mA*0.5=3500mAH at 4.0V would be sufficient i guess.

Now charging condition-> It will charge by C/10 or C/20

Now C=3500mAH, Then charging would be basically 350mA*1hour for C/10 and similarly for C/20.. Correct??

 

[ZASto]

With 350mA you will charge the battery in 10 (Ten) hours
Li-ion batteries need CC/CV charging, not like NiXX batteries that are charged only CC.

 

[KlausST]

Hi,

so 700mA*0.5=3500mAH

use a cacluator.

Klaus