These replacement batteries charge really quickly via USB-C which is super convenient since I can use the same cable as my phone or laptop. They hold a charge just as well as the original Panasonic batteries and fit perfectly in my camera without any wobbling. Having two in the pack means I always have a backup ready, and the USB-C charging lets me top them up anywhere without needing the bulky camera charger when traveling.

The batteries look good in my three Panasonic LUMIX cameras (S5D, S5iix and S9). They are recognized without grumbling and, in my opinion, correspond to an original battery in terms of the battery life that can be achieved with it.

It is practical that the batteries themselves are equipped with a USB-C charging port, which allows you to charge them directly with a suitable USB power supply (e.g. from a smartphone or notebook/laptop) without having to charge them in the camera or with a separate charger. Although I usually still use a 3-slot charger to be able to conveniently charge several batteries at the same time, it's a great thing, especially when you're out and about, if you don't have the charger with you. The camera also remains usable while you charge the other battery.

In my opinion, the batteries are a good choice and an alternative to DMW-BLK22 for Panasonic LUMIX S cameras.

I took the 2-pack K&F CONCEPT compatible DMW-BLK22 (2520 mAh) because I wanted a simple solution: always have batteries ready without going crazy with proprietary chargers or strange sockets. And on this, the strong point is very clear: USB-C charging. Plug in a cable (power bank, phone charger, car, PC) and off you go. For those who travel or take long photo/video days, it's an enormous convenience.

Performance and autonomy
The autonomy is good and, in real use, it behaves consistently: I have not noticed sudden drops or 'strange' behavior. Obviously, compared to the originals (it depends a lot on the camera body and how you record: 4K, stabilization, always-on screen, etc.), there may be a difference, but like spare batteries they do exactly their job: they allow you to continue shooting when the original leaves you on foot.

USB-C charging changes everything
The real advantage is management:
- no mandatory charging base - recharges everywhere

- perfect for backpacks and trips
If you do events, trips, excursions or work where you can't stop, it's a very sensible solution.

Build quality and reliability
The batteries are solid, well finished and do not give the idea of a “cheap” product. Insertion and removal in the chamber ok, without strange games or joints. The fact that they are in double packaging is then the classic smart purchase: you use one, the other is ready or charging.

Things to know (without beating around the bush)
- Don't expect 'miracles': they are great as alternatives/backups, but if you are super picky about the duration identical to the original in every scenario, the original remains the original.
The convenience of USB-C is so great that, for many, it more than makes up for any small difference.

Verdict
If you need a reliable, comfortable spare kit designed for those who move a lot, K&F CONCEPT DMW-BLK22 2-pack USB-C is a good buy. Ideal for travel and long days: less stress, more shots.

Camera sessions used to end far too quickly thanks to batteries running dry, but having these on hand changes the game. They charge fast enough to keep up with busy days and feel sturdy in the camera, giving confidence that they won’t drop power mid-shot. Fit is precise and secure, and they hold charge well even after a few uses. No strange overheating or unexpected quirks, just reliable energy when it matters. Having a pair makes longer shoots much less stressful, and swapping them out is simple and straightforward. Only minor note is remembering which one was used last, but that’s on me rather than the battery.

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.