Coulomb, mA and mAh


I am sure I will forget all this later, so...

A Coulomb (C) is defined as 1A * 1sec. This implies 1A = 1C/sec.

In the previous example, we have a 4V/2600mAh battery driving a 1K resistor. Through the LTC4150, we are measuring consumption of 0.614439C in 150.8s,

    Load = 0.614439C / 150.8s = 0.004075C/s = 4.075mA
    Therefore battery should last 2600mAh/4.075mA = 638 hours

What if you have varying loads? eg.

    (1) Load = 0.614439C for 180s = 0.00341C/s = 3.41mA for 3 mins
    (2) Load = 0.614439C for 60s = 0.01024C/s = 10.24mA for 1 min
    (Repeat)

Then the average load is:

    Average load = 2 * 0.614439C for 240s = 0.00512C/s = 5.12mA
    Therefore battery should last 2600mAh / 5.12mA = 507.8 hours

Comments

Popular posts from this blog

Adding "Stereo Mixer" to Windows 7 with Conexant sound card

Attiny85 timer programming using Timer1

Hacking an analog clock to sync with NTP - Part 5