> The suggestion to use a higher V cell with dropping diodes
> still isn't an option though.
>
> The circuit takes 1.6V at 85nA, which I think is ideal for
> alkalines. The 4 diodes in series with a lithium cell will use
> just as much power (0.136uW) as the circuit itself


The milliamp hour rating of 85 nA  is 85E-9A * 8765 Hour/year *1000  mA/A
mAH
= 0.75 mAH/year
10 years = 7.5 mAH !

This will give you a full 10 year shelf life off all but the very smallest
Lithium cell.
Same for an Alkaline cell but with a reduced shelf life (5 years?)
Working backwards from an incomplete battery table, even a tiny "230" cell =
6mm x 4mm probably has a capacity of 10 to 30 mAH depending on chemistry.

A similar charging current is not liable to do any damage (or quite
possibly, I suspect,  have any significant charging action) on practical
batteries.


        Russell McMahon

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