The circuits in this thread are not for the purpose of charging Li-Ion batteries directly. The circuits in this thread rely on the
mobile device' in-built charging circuitry. For direct charging of batteries, these circuits could be dangerous or damage your battery,
because 5V is not used for these batteries. They require some special considerations, including very accurate charge termination.
A 7805+"proper protection circuits" won't cut it.
For information on what is required to charge them, see a Li-Ion charger IC datasheet, e.g.
this one.
Personally I would use a dedicated charger IC for the specific battery chemistry, unless you are really sure you knew what you are
doing. And even if you knew what you were doing, I would think twice. I've seen what happens when things go wrong with charging
(not specifically with Li-Ion chemistry, but I'm not curious in that respect).