> How large have you made the R1/R1 combination and still gotten decent
> voltage tolerance over "room" temperature range?
>
> The input bias current is rated at 2 to 4 uA +- 0.8 to 2.5 uA over
> temperature range 0 - 70.
>
> Lots better than a zener but maybe would drain the battery fairly
> quickly unless the R1/R2 pair was very high and then input bias current
> shift eats away at accuracy.

His app is a charger.
Power will be on most of the time and even if off is not going to
cause vast problems over charger residency type periods.

18650 LiIon are about 2000 mAh + .

1 mA drain at 24 hours  =3D a bit over 1% capacity.
100 UA - ~0.1%
10 uA ...

In order to avoid thinking about temperature compensation I suggested
he move the voltage back another 0.1 V to 4V.
This reduces capacity but (probably) allows simple float and greatly
improves cycle life.
Also avoids having to do current tail level triggered charge termination.

 R
--=20
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