HCS908LL16/36/64, Battery Capacity, Battery Life Calculation Tool.

[Eng8492]

Where is the authoritative source that gives an AA alkaline cell a capacity of approximately 2800mAh with a 1mA constant load? What did Freescale use for a cutoff voltage?  This is the value predicted by the Freescale battery life calculation tool. A competitor's tool gives AA capacity as 2850mA.

I have read the Energizer and Duracell technical manuals and they do not give battery life or capacity for a 1mA constant load.

The charts start at 10mA load.

[bigmac]

Hello,

For an AA alkaline cell, a load of 10mA would be considered a light load - it is with much heaver loads that the capacity would begin to reduce appreciably.  For a primary cell, such as an alkaline type, the unit to unit variation of capacity would probably be subject to a wide tolerance, so the difference between 2800 and 2850 mAh would be negligible.

For a 1mA constant current load, I suggest that you use the manufacturer's discharge period for a 10mA load, and simply multiply by 10.  The number of hours would then represent the mAh capacity to the particular discharge voltage that you require.

Regards,

Mac