I am a long time K&F Concept customer and have spent hundreds of dollars on their products. Why? because I have found them to be of high quality and a good value for the money. This is the first time I recall being less than 100% satisfied with one of their products.

Before testing, I wanted to ensure the batteries were fully charged, so I popped them into the included battery charger and hooked it up to a fancy PD 3.0 USB charger. I came back after some time and was surprised to see the indicator meters on the battery charger were still flashing (and that they were desynchronized), as pretty much every camera battery I’ve ever gotten has arrived with close to full power. Thinking the issue might be an incompatibility with the PD charger (some “dumb” devices just don’t like it), I switched to a bog-standard USB charger. Came back after a bit and the indicators were still flashing. Came back after several hours and one indicator had gone out (which I assume meant “fully charged”), the other was still flashing.

Wondering if the issue lay with the batteries builtin charging protection circuit or the battery charger, I popped the batteries in another brand’s charger. After a few seconds, the indicator’s stabilized—one battery showing fully charged, the other as still charging. I then tried both batteries in my camera, which reported a 100% charge level on both of them. From evidence, I must conclude that one of the battery’s charging protection circuit is defective and I am concerned that, given how unusually long it took for the other battery to report “fully charged,” that it may have issues too.

The batteries are correctly sized: they fit in the camera without any issue. As they seem to be functioning just fine (apart from the afore mentioned charging oddities, which I think warrants at the very least a 1 star deduction), I’m going to give them a decent rating. I’ll update this review if any other issues arise.

[Disclosure: I received this product for “free”—in quotes because the IRS considers the item’s retail value as taxable income for federal income tax purposes. This review is my personally written—not AI generated—honest opinion, and is uncensored by the seller.]