Hallo Robert,

charging batteries has become a 'sience' today. You must have a look at those various acpplication notes published by Maxim! Have a look for instance at:

http://www.maxim-ic.com/appnotes....number/680

or

http://www.maxim-ic.com/quick_vie...1666/ln/en

But there are many others...

In former days NiCd batteries were mostly charged by C/10 for 14 hours. But today fast charging techniques are used, taking the change rate of cell voltage as an indication of progress of charging. These modern sophisticated charging methodes are so complex that you need an integrated chip containing all the necessary stages. So, finally you will end up using one of the special chips from Maxim (or others).

Kai