K&F Concept KF-V99 SE review: 99 Wh for the rig and the plane

The battery has a capacity of 99 Wh at a nominal 14.8 V, which is 6700 mAh. Watt-hours are a more useful figure for comparison than milliamp-hours because they include voltage – and they are also what air travel rules are based on.

The manufacturer quotes dimensions of 104 × 74 × 50 mm and a weight of 525 g. It is therefore a compact design that adds less bulk to a cage, arm or tripod. The housing is fire-resistant polycarbonate in graphite black. On a camera, bear in mind that the battery will still shift the rig's centre of gravity towards the back.

Besides the V-mount plate, which powers a camera or light directly, the battery offers 100 W USB-C, 24 W USB-A, 2× D-Tap, a 12 V DC output (5.5 × 2.5 mm connector) and BP contacts. The ports work in parallel, so one battery can, for example, power a monitor via D-Tap while charging a phone over USB.

According to the manufacturer, the two D-Tap ports sit on the sides of the body, which helps with cable routing around a cage. The labelled diagram marks both D-Tap and the BP contacts as input and output; however, the manufacturer only gives a charging time for USB-C.

The USB-C port charges the battery and powers other devices, at up to 100 W in either direction. With an adapter of at least 100 W, the manufacturer says a full charge takes roughly 2 hours; a weaker adapter will take longer.

The battery supports common fast-charging protocols – PD 3.0, PPS, QC 3.0 and 2.0, AFC, FCP, SCP and Apple charging. In its graphic showing a phone and tablet charging at the same time, the manufacturer states a 100 W maximum, so the power is shared between ports. It can handle a USB-C laptop as long as the laptop does not demand more than 100 W.

You can estimate runtime simply: divide the 99 Wh capacity by the power draw of the connected devices. Conversion losses mean the real figure will be lower; as a rough estimate, allow for about 80% of the theoretical value.

A camera and monitor drawing 20 W together would theoretically run for 99 / 20 ≈ 5 h, realistically closer to 4 h. A 60 W LED light works out at 99 / 60 ≈ 1.6 h, realistically about 1 h 20 min. A laptop with its own 60 Wh battery can be recharged roughly once.

This is a calculation, not a measurement. Check the actual power draw in your devices' specifications.

Under IATA rules, the limit for lithium-ion batteries in air travel is 100 Wh. Passengers may carry spare batteries up to this capacity without airline approval, but only in hand luggage – they must not go in checked baggage. The terminals should be protected against short circuits, for example in the original packaging or a separate bag.

With 99 Wh, the KF-V99 SE falls below the limit, and the manufacturer describes it as suitable for carrying on board. Airlines may still set their own restrictions, such as on the number of batteries, so it is worth checking your carrier's conditions before you travel.

A BMS looks after the cells, with protection against overheating, overvoltage, over-discharge, overcurrent, overcharging and short circuits. On the back there is an emergency light, which the manufacturer says helps when fitting the battery in the dark.

The charge level is shown only by an indicator on the body. There is no display showing percentage, remaining time or current draw, so runtime has to be judged from the indicator and your own calculation. The box contains the battery, a USB-C charging cable and a manual; you will need your own USB-C adapter of at least 100 W.