Hallo Steve,

I aggree with you. What things complicate even further is, that in such application it cannot be excluded that some time Ayman exchanges his battery to one of the wrong chemistry. Then he will not benefit of a well designed circuit that was well matched to the 'original' one with it's well know chemistry.
Just think of situation that Ayman puts into his application which is designed for using NiCd battery, an alkaline cell, because he has no NiCd types on stock...

By the way, some weeks ago in Austria (Europe) a built-in Nokia cellphone battery exploded and caused a damage like a small bomb. Happily cellphone was not just in hand of user. It was reported in tv. It was assumed that charging circuit has failed...

Bye,
Kai