Amazon Affiliate Link:
https://amzn.to/4pOBoKcPrice as reviewed: $109
NEEWER Mini V Mount Battery, 6800mAh 99Wh V Lock Battery, PD65W Fast Charging/D Tap/BP/USB A/Dual DC Port/OLED Display for Camcorder Video Camera Compatible with SmallRig BMPCC 4k 6k, PS099E
This V-Mount battery delivered D-tap and Bport power as expected, along with 8v and 12v plugs (max 3 amp). It exceeded it's specifications on the USB ports however. While the manual and listing states that it supports Power Delivery 65 watts, I was actually able to charge the device at a full 100 watts (20 volts @ 5 amps) rate.
I tested 60 watt PD output (I don't have a device to push it past that) but I wouldn't be surprised if the USB-C port could also export up to 5 amps at 20 volts. The listing states that if you use both USB A and USB C ports the voltage drops to 5 volts, but I was able to successfully power a laptop at 20 volts (30-60 watts) while simultaneously drawing 15 watts at 5 volts from the USB-A port, so it appears that the USB ports are better than the listing and manual state.
Capacity testing, it delivered 85 watt hours out of the USB-A port at 5 volts @ 3 amps. When testing the BP output at 6.5 amps, it only delivered 75-80 watt hours. Given efficiency losses in voltage conversions on the USB subsystem and the high discharge rate via the BP, this feels reasonable given that the capacity specification is 99 watt hours. It took 103 watt hours to recharge the battery from empty, so it is possible that the actual capacity is closer to 90-95 watt hours.
The battery has a single button that turns on the display and flips between two screens. The first screen shows the battery percentage and the voltages of each output port (if being used). The 2nd screen shows the battery voltage and the voltage and amp draw on each of the ports. The only feature I really missed from the screen is an "in" or "out" display to determine if a USB-C device is charging the battery or drawing power from it.
This battery is very much a direct competitor to the SmallRig VB99 battery, and as far as I can tell, it delivers basically the same feature and performance for almost half the cost.
SmallRig VB99 affiliate link:
https://amzn.to/4pKQEYx