Just wondering usually how long does CMOS battery last on a regular motherboard?
I read that motherboard leakage current of about 3 - 6 micro ampere. I did a calculation below but I believe that i may have missed something. What is the minimal voltage required for a motherboard's date/time function to work correctly?
Life of battery (down to 0V):
Normal Case (leakage current = 4 µA).
Battery capacity = 225 mAH / 4 µA
= (225 x 10^(-3)) / (4 x 10^(-6)) hr = 56250 hrs
One year has 24 x 365 hrs = 8760 hrs
Total battery life (from 3V -> 0V)
= 56250 hrs / 8760 hr per year = 6.42 years