Mobile Phone Batteries

[imported_rod]

I'm thinking of building a USB mobile phone battery charger, and I'm just wondering if anyone knows anything about mobile phone batteries (especially Li-ion ones) and charging them.

I know some Li-ion batteries have built-incircuitry which controls charging, and all they require is a clean dc voltage. Do Mobile Phone batteries behave like this, or do they require charging circuitry and the like???

Thanks all
RoD

 

[imported_rod]

No-one's replied, so im posting this in General Hardware.