mWH - mAH conversion

[guzfrie]

Dear Passmark,

I just used BatteryMon demo version to measure a Portege R380 battery performance. The result shows design capacity of 65668 mWH (6566 mAH) and voltage of 10.8 V. Since ampere is watt divided by voltage, the number in the bracket, which presents capacity in mili ampere, seems to be incorrect then.
To answer my curiosity, I did the same thing in my friend's laptop, Lifebook 6410. Unfortunately, the result was quite similar: 56160 mWH (4680 mAH), 12.56 Volt. The mWH - mAH conversion does not use the common formula. It became confusing then as I realized that the capacity information written on the battery are 5800 mAH and 5200 mAH for Portege and Lifebook respectively.

So, how does BatteryMon convert mWH to mAH?
Which is the correct information, the BatteryMon results or those are written on the body of the battery?
Thank you

[Tim (PassMark)]

Thanks for reporting this, it was due a precision error when calculating the mAh (voltage was being rounded down), there is a new build available at http://www.passmark.com/products/batmon.htm to correct this error.