I have a Lumix and I always carried the official charger plus cables and adapters, it was a pain. With these K&F I simply stick the batteries and a USB-C cable in the backpack and that's it, problem solved.

The measured voltage matches a new OEM battery that I have, which gives me confidence. I used cheap batteries before that gave less voltage and caused my camera to fail so now I always check this. These passed the test without problems. The integrated USB-C charging is the product's strong suit. I can charge from any USB power source, whether it's a wall adapter, car charger, powerbank or laptop. Very versatile for different situations. The charging time is around 2.5 hours with a good USB charger, although it can be slightly longer if you use a basic 5V source. The LED indicator helps to know the status without complications.

Safety certifications (CE, FCC, RoHS) and overload and temperature protections provide peace of mind during use. The case is made of lightweight but well-fitting plastic, perhaps not as robust as the original ones but perfectly functional.

A detail to keep in mind is that due to their universal design they do not fit standard Lumix chargers, you have to use only USB-C charging.