Depending on your location or region, your sources of such products
can vary in both quality &/or quantity. Most will not be like the original
exactly, because the official sources aren't making them for Apple.
Usually I've always been on the look-out for original products where
they may appear; such as 'second hand stores' where used ones
can appear & so I look around, for items I may need eventually...
And so I have some duplicate original Apple adapters + other parts.
APLPBI65W NewerTech (65W )AC Power Adapter (100~240v 50/60hz auto switch-
ing) for all models Powerbook G4 12/15/17 AL Ti, Apple iBook G3/G4 (Dual USB).
For a new generic product (like above, a used one I was given) the
'newertech' brand sells a good model. But this does not indicate any
level of charge on the DC-plug that goes into the PPC portable Mac.
Example of one for travel that uses automobile power 12V. from same
vendor (and elsewhere) adapts PowerBook/iBook to car power. See:
APLPBIBAUTO NewerTechCar/Auto 12V Charger for PowerBook
G4, iBook G4/G3... NewerTech60w
These can be available in other regions through their reseller network
The power plug is of correct shape, output is good & theirs will work.
{Clones of the original Apple power adapters for white G3/G4 iBook
and PowerBook models may do OK; but the quality varies a lot.}
Seems this same item has been referred to as example of replacement here:
Re: Have lost the charger cord for my old iBook 12/1, Where can I find a new one
Sometimes retail stores such as WalMart may offer a cheap
copy of some power adapter that could work for a time.
Good luck & happy computing! 🙂