K&F CONCEPT NP-FZ100 dual-slot fast charger, Micro USB and Type-C dual interface, compatible with battery Sony Alpha A7 III, A7R III (A7R3), A9, a6600, a7R IV, Alpha a9 II USB data cable battery charger

I got these in a very secure package. I opened the packing and found a charger Almost the same as the original fuji charger and the batteries are very durable. So far they hold a good life of shooting. I would say I went out yesterday and spent about 6 hours in the field and the battery lasted. it was not constant use, However it was used pretty much for shooting and BTS 4k video( which uses up battery fast) So far so good. I recommend these over any 3rd party battery.

A good value third party charger. Small and neat, decent build quality. Charging time good, does exactly what its meant to do.

These 3rd party batteries are almost like the original that came with my X-T5. Out of the box, they were already 75% charge. Nice.

Physically, they are identical except for one thing, as far as I can tell. The ends of these batteries are not completely flat. If you place one on its end, you can rock it back and forth. About a third of the ends has a slight bevel. Nonetheless, these batteries go in and out of the camera without any issues. Another oddity is that the orange covers can only snap into place in one orientation. And the reason I find this odd is because the covers have a battery shape cutout that you can use to identify whether the battery is charged or not by the orientation the cover is attached. These covers don’t fit the original Fuji battery, because its ends aren’t beveled.

Weight wise, original=80g, these=78g. Close enough.

Electrically, these batteries seem to perform the same as the original, despite the 0.2V higher output voltage and 0.2Wh higher capacity specs. They don’t generate more heat nor have any side effects, as far as I can tell. The X-T5 was even able to read the age of these batteries (yes, as new.)

Unscientific methods show that the discharge and charge times between these and the original are roughly the same. Using the included cradle and the 5V,3A AC adapter that came with my X-T5, charging a single battery from near 0% to 100% took about roughly 4 hours. The cradle regulates the power output to 8.4V, 700mA for one battery and 8.4V, 500mA for two batteries. K&F specs an AC adapter capable of at least 5V, 2.1A , and using a more powerful adapter probably isn’t going to help with charge times.

Each of these batteries (at the time of this review) is about 1/3 the price of the Fuji’s, which given how they perform, is a great deal. I can’t tell yet how they perform in the long term, but given the price, I don’t think I can complain regardless.

This is a very handy, compact battery set for Fuji cameras. I personally have a Fuji X-T4, and that is the camera I tested these batteries with.
The negative aspects of the unit: The unit doesn’t come with a power plug—it only comes with a USB-A to USB-C cord, which would allow you to plug the unit into some other USB power device that then plugs into the wall. The only other thing is that the LED display of the charger is on the bright side, and might need to be covered up with another item or some light dimming stickers, especially if you’re traveling with this charger in a small hotel room.
This unit is very compact in size and would be very easy to travel with. The base of the charger is only slighter in surface area than if you were to lay the two batteries flat on a table next to one another. The batteries plug into the unit vertically, though, as the “butt” end of the battery makes a connection with the charging prongs of the charger. Also, the mobile charger appears to have two power inputs: A USB-C one (which would work natively with the USB-C cable included with the unit) AND a micro USB connector! This flexibility is ultra handy if you have extra micro-USB cables lying around and you need to poach that valuable USB-C cable for some other device you’re traveling with. (Note: I have not tested charging batteries in the unit with the micro-USB interface. If I do and I have issues with it, I will come back and update this review.). Also, there are animated LEDs that describe the status of charging each battery, independently of one another. This feedback is nice to be able to see how close you are to a full charge.
The batteries that come with this unit feel pretty solid and comparable to Fuji stock batteries. Comparing the battery to the Fuji battery that came with my XT-4, the only notable difference I see on the label of the battery is that the voltage and Watt hours of the batteries are slightly different. (The authentic battery that came with my camera reports 7.2 V, 2200 mAh, and 16 Wh. The sticker on these batteries indicate that the batteries output are 7.4 V, 2200 mAh, and 16 .2 Wh. This would mean that the batteries that come with this charger are nominally higher voltage, though this doesn’t seem to make a difference to my camera.) Like the authentic Fuji batteries, the (2) batteries that come in this package are also Lithium Ion. I have tested these batteries in my camera and so far, they appear to operate identically to the stock Fuji battery of my camera.
Overall, I’m very satisfied with this product, and would recommend it to anyone who has an X-T4 or any other type of Fuji camera that uses these batteries.

So far works as expected as the original Fujifilm NP-W235 batteries. No warning in the camera indicator, no heat-up, and they last as long as the original ones.
The charger is also beneficial since no external charger is included in the camera kit. It provides much convenience when traveling and you need to charge more than one battery at the same time.

I waited a bit before writing this review to see if there would be any issues that crop up. Fortunately, the charger works perfectly (charges OEM Sony batteries also). The fact you can connect it to a power bank is a massive bonus for me especially when out in the woods with no AC outlet options.

It does what it do

Works well

The charger and batteries that replace the Sony NP-FZ100 are great, and cost half as much. They fit my camera like an OEM battery and work really well. I can't imagine paying full price for a Sony battery. There's no noticeable difference.

I ordered this product for two reasons.
1. I wanted additional batteries, of course
2. I wanted an external charger.

The batteries have exactly the same power and capacity as the original battery. I have felt the same way so far and can't tell so far that these batteries run out faster.

The charger is extremely light (plasitk) and really fits quickly in your pocket, it fits in the photo bag or backpack. It has a display showing the charging status of the batteries (1-4/5 bars). You can connect the charger anywhere, it has 2 interfaces, either via a micro USB cable (included) or with a USB-C cable (not included). This is convenient, of course, since one of them usually has everyone somewhere, and even in the car above the cigarettes lighter with charger, they can be charged without any problems.

The original battery charges the same as K&F Concept's, so everything I assumed has been fulfilled.

The price is of course another extra point, considering that a single Sony battery cost around €65 and you get 2 here including a charger.