It works for my a7rv and I'm happy. I needed the extra 3 batteries and being able to charge up to three batteries at a time is the best.

Batteries in line with the description, perfect for Sony a7 IV

I bought the K&F Concept NP-FZ100 battery set (pack of 3) for my Sony ZV-E1 and A7IV because I often do long shoots and photo sessions and don't want to be tied to the charger all the time. After several weeks of use, I can say: The batteries deliver very good performance and are hardly inferior to the original battery.

Runtime & performance
The batteries last a very long time, almost as good as the originals from Sony. With the ZV-E1, I use them for video recordings in 4K, and I easily get several hours of use - depending on the recording settings. It's a similar story with the A7IV, especially for photography, one battery is enough for a complete session.

Workmanship & fit
The batteries fit perfectly in both cameras and in the charger. No wobbling, no problem with detection - the camera shows the battery level correctly. This is important because some third-party batteries sometimes have problems here.

Price-performance
For the price you get three batteries, which is a real bargain compared to the Sony original. Sure, Sony batteries are probably slightly better in terms of efficiency and lifespan, but if you film or take photos a lot, you'll be absolutely happy with these.

Conclusion
If you're looking for a cheap but reliable alternative to the original batteries, you can go for this one without hesitation. Long runtime, no compatibility problems and great value for money. I'll definitely get some more if I need them!

Obviously they run out of battery sooner than the original ones, but I mainly use these for every shooting I go on.
Rather than using (and therefore “ruining”) the original Sony ones quickly, I prefer to use these and in the worst case scenario buy new ones in a year, given the very low price

I recently picked up the K&F Concept NP-FZ100 replacement batteries for my Sony A7 IV, and I have to say, I’m really impressed! These batteries hold a charge surprisingly well, almost on par with the original Sony batteries. I was able to shoot for hours without worrying about running out of power.

The included dual charger is a nice bonus—it’s compact, charges via USB-C, and allows me to charge both batteries at the same time. Perfect for travel or on-the-go shooting.

For the price, these batteries are a fantastic value. If you need reliable backups or extra power for long shoots, this is a great choice. Highly recommended!

✅ Pros:
✔️ Long-lasting battery life
✔️ Dual charger with USB-C
✔️ Great value for the price

Must have additional batteries for Sony camera when doing longer day shoot. Charge lasts long. Charging station is also of good quality and shows the percentage of battery being charged.

They work perfectly, just like the originals. They may last a little less time, but for the price you can't ask for more. I'm delighted with them.

Use for photography and video bargain can’t complain for price charges quick if you need it

very good performance of the batteries, no less than the original

One of the three batteries lost capacity faster than the others, the support sent me a replacement.

I have extensively tested the two batteries that worked well from the start and am impressed with their performance; there is hardly any difference to the original battery for a fraction of the price.