This Box Charges EVERYTHING – USB PD + USB PPS Explained (feat Sabrent Voltik)
This box is kinda magic. Between those four USB C ports and four USB A ports this thing can power 252 watts worth of stuff, and more importantly it can power ANYTHING between 3.3 and 21 volts. Pretty sweet right? I think so, but I think the coolest thing is HOW it does that, so while we will take a look at this bad boy, I want to focus on how it works, so let’s get into it.
What this is is Sabrent’s Voltik 252W 8 port charger, complete with four USB C ports capable of delivering 100W, or 125W between a pair, or 250 watts between all four. It has a built-in display to show you what each port is doing, or get details on specific ports, and importantly, this is a very smart charger as each port can be doing something different – well each USB C port anyway. Amazingly the USB A ports on here can actually be set to 18 watts per port, or 36 watts per pair, with some amount of PD control apparently possible. As for input, this takes a two pin AC power cable in, which explains why this little brick is so damn heavy.
The true magic here though is the two USB standards that make this truly smart, USB PD (power delivery), and USB PPS (programmable power supply). Let’s start with the more popular former, PD. The USB Power Delivery standard came about because people really wanted to have one cable to rule them all. Well actually it’s because we’ve been using USB A and B ports to power stuff since the dawn of time, although if anyone remembers old external hard drives that needed both a USB B cable AND an external power supply, that’s pretty much what USB PD is meant to fix. Instead of the power supply just dumping 5 volts and generally no more than two amps (for 10 watts total) indiscriminately, USB PD asks you to add a chip to both the charger and the device and do a bit of a dance – a handshake, if you will – to work out what the device needs. USB PD has a fixed set of voltages, generally 5V, 9V, 12V, 15V and 20V, and the amount of current available at each level varies depending on the power supply. This Voltik can do 3 amps at any voltage level, or 5 amps at 20 volts to be able to reach that 100 watt limit.
There’s a subtle but pretty massive shift in the way things work there – up until USB PD, power supplies are all pretty fixed. Like, a USB A port gives you 5V. That doesn’t change. It can’t. Your laptop’s charger, the barrel jack type anyway, likely provides somewhere between 15 and 20 volts and doesn’t change. Your power supply has specific wires for specific voltages – you can’t just change what voltage is on one of the 12 volt wires, it’s fixed. But with USB PD and a bit of negotiation the power supply can start at 5V, then when it’s sure the device wants more, switches to 9, 12, 15 or 20, and can then open the flood gates for up to 3 or 5 amps of current to rush through a single USB C port. That’s pretty cool.
USB PD is arguably the most important feature here for sure – this is what lets you charge your laptop, and run, say, a desktop all-SSD NAS, AND charge your phone, all at different voltages and current levels. But there is one other feature that is much more rarely used, and yet is, to me anyway, so much cooler. While it’s one thing to have fixed voltage steps, it’s another thing entirely to have full control over the voltage. To be able to set it to 3.3V, or 6.2V, or 11.5V, or 13.8V, or anything in between. That’s what USB PPS offers. PPS, or programmable power supply, lets the chips on either end of the cable not only ask for one of the set voltages, but for any voltage within the range, and to change it at any moment. If you want to charge a battery, you often set a high initial charging voltage, but then as you get closer to the battery being full you bring it down to a safer resting voltage. Instead of your charger needing to do that, you can just request the USB PPS do it on the fly, and it will! If you want to use this as a digital power supply for testing electronics, you can. If you want to use this for powering something that doesn’t use one of the PD voltages, just use an adapter board to request the specific voltage and current (up to 3 amps). I don’t know about you but I think that’s really cool.
To point our focus back on the Voltik for a moment, it is worth noting for those who are considering picking one of these up that this does have a somewhat complicated mix of options if you need a lot of power from this thing. There are actually two pairs of USB C ports, and two pairs of USB A ports, with two A and two C per group. All the A ports feed from the same power rail, which can supply 126 watts at most. That means if you have two 100 watt devices to power/charge, you’ll want to use ports C1A and C1B as they are pulling from different internal rails. That then leaves 26 watts for other devices per bank, either up to 25 watts over the other Type C port, or 18 watts from a USB A port. As for the display, that defaults to the 8 port view showing the power each port is drawing, although if you press the button you can then cycle through each individual port to see what voltage and current its drawing, the temperature of the port, and the time it has been connected. Considering this thing is about £70, for what you’re getting it’s hard to argue this isn’t a really cool and useful bit of kit. I’m happy to have it, even if Sabrent did send it over – although as usual they have no editorial control in this video nor get to see it before publication. If you want one of these yourself I’ll leave an Amazon affiliate link in the description – see that’s how I get paid from this, not from Sabrent!
