I use the original Pentax charger for the K-5 and the original charger of Panasonic for the Lumix.
The reserve batteries of both are Pantonas, no problems yet. The Pantonas give less shots than the Pentax ones, and most likely will last half as long, but they cost a fraction of the original batteries from Pentax and Panasonic (the same with my IBM/Lenovo Thinkpad notebook).
But my old Lumix (also bought used) came with a cheap chinese charger (without the 3rd contact) and caused all kind of problems. I finally replaced it by the Panasonic charger (at a hefty price), but no problems anymore.
The original chargers may be produced in the same chinese factories as the cheap ones, but they will have an approved electronic design and a tight quality control
Last edited by RKKS08; 09-19-2018 at 02:47 PM.
Reason: Typing