K&F Concept KF-V99 Pro and KF-V50 Review – Budget-Friendly V-Mount Batteries

Battery Review

by Marcel Klien15 days ago

Chinese manufacturer K&F Concept is an established and well-known brand with affordable options when it comes to filters, cameras, and other videography/photography equipment. This time, we are taking a closer look at their V-lock 50Wh and 99Wh batteries, the K&F Concept KF-V99 Pro and KF-V50. Keep reading for a full review!

Before we get started, in case you missed it, I also reviewed their affordable Mini Matte Box, which you can read up on here. So, let’s jump right in and clarify some of the terminology used in this article.

What is V-lock/V-mount?

A V-lock battery is a rechargeable battery that uses a V-shaped locking mechanism to attach to professional equipment like cinema cameras, monitors, and lights. It’s designed for high-performance and high-power usage in film, broadcast, and photography applications.

The rumour says that a Chinese engineer who worked for Sony invented the V-lock battery standard in 1993 because Sony wasn’t open to paying the patent for Anton Bauer’s Gold Mount. The Gold Mount is another cine standard, but is mostly used in North America. Some would say it’s better because of its presumably better locking system, but honestly, that’s just more hearsay than actual proof.

What makes V-lock/V-mount a standard in the industry?

• 12V–14.4V output or higher, depending on the battery model.
• Output support (USB-A/C, DC barrel jack, and D-Tap).
• An easy and fast way to swap.
• Supported by professional gear like field monitors, cine cameras, wireless transmitters and receivers, and LED lights.

K&F Concept KF-V50 and KF-V99 Pro

Both batteries are built equally and are packaged the same, so we will get into mentioning their differences later. First, let’s concentrate on the build quality and what you get for your money. Here is an overview of what you get straight out of the box:

KF-V50:

• KF V50 V-Lock/V-Mount
• 240W USB-C Charging Cable
• Manual

KF-V99 Pro:

• KF V99 Pro V-Lock/V-Mount
• 240W USB-C Charging Cable
• Manual

First impressions

The batteries are made of a mix of aluminium and fireproof polycarbonates (PC), or in other words, durable plastic. They feel durable, and the aluminum keeps them sturdy and bump-proof. The front side, however, feels less “high-end” as the glare surface easily collects fingerprints and scratches. 

On the left side, you have a button to activate the small TFT color screen that’s on the front side, and with it, one can monitor the charge and power output on the different outputs. It is a great feature to easily check if every accessory gets the needed power. Unfortunately, when opening it, the upper lid that protects the USB and barrel connectors broke on the V99 Pro. A sturdier mechanism instead of the rubber lid would be something to consider in the future, so this doesn’t happen to users. Both the KF-V50 and KF-V99 have an LED light built into the V-lock; it can be activated by pressing the power button for three seconds. This feature was missed in their older model, so it’s nice to see K&F Concept steadily improving their V-lock/V-mount batteries!

The USB-C cable included with the batteries is a sleeved 240W cable — far more powerful than the batteries require. However, K&F Concept explained that they chose this cable so users could also use it with other accessories that have higher power demands.

Additionally, both batteries are “travel safe”, meaning you can carry them in your hand luggage. Generally, a common rule for V-lock/V-mount batteries is that everything under 100Wh is allowed to be carried onboard. Though some airlines do limit how many batteries can be carried in your hand luggage, so keep that in mind when you’re traveling!

BMS (Battery Management System)

Both batteries use a standard BMS, and it’s impressive to see BMS technology implemented even in small batteries like these. But what exactly is a BMS? A BMS, or Battery Management System, is an electronic system that manages and protects a rechargeable battery pack. Whether it’s a small camera battery or a giant electric vehicle battery pack, you can think of the BMS as the “brain” that monitors and safeguards the battery cells.

So, what does a BMS actually do? This is where our small TFT screen comes in handy — it helps display key information about the BMS’s functions. Here’s a brief overview of the core tasks a BMS performs:

1. Monitors battery health

• Checks voltage, current, and temperature of each cell or the entire pack.
• Ensures all cells are operating within safe ranges.

2. Protects against damage

Prevents:

• Overcharging
• Over-discharging
• Overheating
• Short circuits
• Excessive current draw

3. Cell balancing

• Ensures that all cells in a multi-cell pack have the same voltage level.
• This maximizes battery life and performance.

4. State of charge (SoC) estimation

• Tells you how much power is left (like a fuel gauge).
• Helps predict runtime and when to recharge.

5. State of health (SoH) estimation

• Tells you how much life the battery has left.
• Useful for long-term battery monitoring and replacement planning.

6. Communication

• Sends data to a display, charger, or external device.
• Used in EVs, drones, or high-end cameras to report battery stats.

To see BMS in two of the most affordable V-lock/V-mount batteries we’ve ever tested is truly a very pleasant surprise.

K&F Concept KF-V50

The KF-V50 with its 50Wh and 3400mAh capacity is on the smaller end of the spectrum when it comes to V-lock/V-mount batteries. This can be a limitation if you’re powering large cameras or running multiple accessories. However, its compact size and lightweight design make it an excellent solution for smaller DSLR or mirrorless rigs, handheld monitors, and similar setups.

Outputs

The V50 has the following four outputs to power accessories:

• USB-C: 65W
• USB-A: 24W
• DC Barrel Jack: 12V – 3A
• BP/D-Tap: 11.2V – 16.8V, 8A

Having this many outputs for such a small battery is impressive, and I can tell no compromizes were made here.

Inputs/Charging

Charging the KF-V50 works like any standard V-lock/V-mount battery: simply plug it into a V-mount charger. Charge time to 100% is about two hours, depending on the charger used. Unfortunately, the company does not currently offer V-mount single or dual chargers in their product lineup.

Beyond traditional charging, the KF-V50 can also be charged via USB-C and D-Tap. This flexibility means you can top it up on the go using a phone charger or a more affordable D-Tap charger — an especially handy feature on busy sets. Still, we’d love to see K&F Concept offer some dedicated charging solutions in the future.

 Specifications

• Model: KF-V50
• Type: V-Lock/ V-Mount
• Weight: 397g
• Rated Capacity: 14,8V | 3400mAh | 50Wh
• Total Output Power: 65W (Max)

Input:

• USB-C: 20V- 2,25A | 45W (Max)
• BP/D-Tap: 16,8V 2,5A (Max)

Output:

• USB-C: 5V-3A | 9V-3A | 12VV-3A | 15V-3A | 20V-3,25A | 65 W (Max)
• USB-A: 5V-3A | 9V-2A | 12V-2A | 24W (Max)
• DC: 12V-3A
• BP/D-Tap: 11.2–16.8V, 8A (max)

K&F Concept KF-V99 Pro

Now, let’s look at the V99 Pro. This model offers more capacity and higher output at the cost of slightly more weight and size. With 99Wh and up to 100W output, the V99 Pro is perfect for mid-sized cameras like the Sony FX6 or for handheld rigs that require longer run times. Despite its increased performance, it remains relatively lightweight at 645g, especially considering its extensive range of inputs and outputs.

Outputs

The V99 Pro has 5 outputs with a combined maximum output of 100W:

• USB-C1: 100W 
• USB-C2: 65W
• USB-A: 24W
• DC Barrel Jack: 12V-3A
• BP/D-Tap: 14,8V-12A 

The standout feature here is the 100W USB-C1 port, which can power MacBooks, fast-charge iPhones, and handle demanding accessories. Having a second USB-C port increases your flexibility, but keep in mind the total combined output is capped at 100W, so the available power per port may vary if you use multiple outputs simultaneously.

Inputs/Charging

Charging the V99 Pro is similar to the V50, but only the orange USB-C1 port supports charging. Thanks to its 100W USB-C input, you can fully recharge the 99Wh battery in around 2 hours — impressive for a battery of this size.

Specifications

• Model: KF-V99 Pro
• Type: V-Lock/ V-Mount
• Weight: 645g
• Rated Capacity: 14,8V | 6,7Ah | 99,16Wh
• Total Output Power: 100W (Max)

Input:

• USB-C: 20V-5A 100W (Max) 
• BP/D-Tap: 7A (Max)

Output:

• USB-C1: 15V-3A | 9V-3A | 12V-3A | 15V-3A | 20V-5A 100W (Max)
• USB-C2: 15V-3A | 9V-3A | 12V-3A | 15V-3A | 20V-3,25V 65W (Max)
• USB-A: 15V-3A | 9V-2A | 12V-2A 24W (Max)
• DC: 12V-3A
• BP/D-Tap: 14,8V–12A

Final thoughts

We already mentioned that the build quality of the protective rubber lid isn’t that great, and this counts for both batteries. When I tested the V99 Pro, the rubber lid ripped off while working with it. In a busy situation on set, for example, switching batteries seconds before we must roll the camera, I need to be sure that I can easily plug in cables without having the struggle to open a lid where the connectors are, or take the extra attention not to just rip the rubber cover off. Many other brands fixed that issue with a hard plastic lid. I would’ve loved to see such a solution on a battery that is labeled “Pro”, too.

Mostly, when you must implement V-lock/V-mount into a workflow, you have to spend a lot of money on chargers and batteries. Both the V50 and the V99 Pro are a great start into the world of V-lock/V-mount. They’re simple to understand, offer a lot of charging/powering flexibility, and have enough capacity for powering different accessories for a long period of time.

Both the KF-V50 ($99.99) and KF-V99 Pro ($119.99) are good, affordable choices when you can overlook the drawbacks of the rubber lid and glossy frontplate. I would love to see K&F Concept upscale their game with higher capacity products like 150Wh or 200Wh batteries, as those will be a great alternative for bigger cameras like the Alexa Mini or LF.

What do you think about the new K&F Concept batteries? Do you see yourself giving them a try? Please share your thoughts with us in the comment section below