Priority Charging
The Plugable PS-10CC Type-C Power Delivery 10-Port Priority Charger is designed to ensure that your devices are charged efficiently and in priority order—from left to right. Why does the PS-10CC do this? Let's take a look at an example below.
Example: 10 laptops connected to a PS-10CC, with a 100W USB-C PD power supply connected and powering the PS-10CC.
First it's important to note that the PS-10CC cannot take the 100W of input power from the attached USB-C PD power supply and charge all 10 laptops simultaneously at 100W each - the PS-10CC ultimately can't generate more power than what's available to it from the PD power supply. At the same time, these laptops likely wouldn't accept just 10W charging if the power were split evenly across all ports, and the PS-10CC reserves some power for itself to operate.
So how does the PS-10CC charge the attached devices? This is where the PS-10CC stands apart from other charging options, it intelligently takes into account the input power it has available to it from your attached PD power supply (18W to 100W), and the power required for the attached devices. It then begins charging your attached devices at the best rate possible and in priority order.
If there is a laptop attached to the leftmost priority port and charging at 85W, this would consume most of the available 100W input power from our example above, leaving little to charge anything else attached. However, as the laptop charging nears completion and as the wattage required (the electrical current) drops, the PS-10CC can then reallocate the available power and to begin charging the next device(s) inline based on their charging needs. In the case with laptops, this could mean that the PS-10CC will primarily charge them one at a time due to their high power requirements.
If there are multiple small devices connected that do not require as much wattage as a typical laptop, like a phone or laptop then the PS-10CC will be capable of charging multiple of those devices at a time.
Charging Times
The PS-10CC charging times will ultimately vary depending on input power and connected devices. As you are using the PS-10CC charger you could notice that there may appear to be additional time where a device appears to be charged, or waiting to charge, but the LED lights on the PS-10CC haven't changed their status yet. The PS-10CC must wait for the charging - specifically, the electrical current flowing from charger to device, to stabilize before it can decide if and how much power it can spare to begin charging the next device(s) inline. If changes are made too quickly it could cause devices to not charge as expected or the power distribution may be less accurate/optimal for the devices, so the PS-10CC has been optimized to have a balance between speed and reliable charging results.
It's also important to know that the charger does not have access to the devices’ battery controller and cannot know the charge level of the connected device(s), as the USB-C specification doesn't offer this capability. So the PS-10CC judges charge levels based on the flow of electrical current that is being drawn from the device(s) and it monitors the current until it drops below a particular threshold and over time.
The overall charging behavior and time that it takes can vary as devices themselves will also have varied charging behaviors. So for example, some devices may end their charge cycle with a slow trickle of current and wait at that current for a while, while others may charge at a high current right up to the end and abruptly stop. So the nuances of these charging behaviors on a per-device basis can delay the charger from moving to the next port (or allow the charger to move to the next port more quickly for others).
Generally speaking, it can take about ~5 minutes for the charger to update status LEDs and move to the next device(s) inline if the conditions are appropriate (when the current falls below the threshold and stabilizes). But depending on the devices and their charging behaviors that time may be longer.
Legacy Devices
(non USB-C, no Power Delivery capabilities)
Due to limitations of the USB-C specification there are inherently some complications surrounding charging of legacy devices. Primarily, by connecting a legacy USB device to the PS-10CC using a USB-C to legacy cable (such as a USB-C to USB Micro-B or Apple Lightning cable for example), the USB-C Power Delivery controller(s) in the PS-10CC cannot know if there is a device connected to the legacy end of the cable. As such the USB-C PD controller simply makes the assumption that there is a device connected and outputs power when the cable is attached, regardless if a device is or is not actually connected to the cable. Due to this behavior, and the priority charging mechanism of the PS-10CC, this has a few implications that must be considered:
- When a legacy cable and device are connected and after the device has been charged and disconnected, if the cable is left connected the PS-10CC will be unaware of the device being disconnected from the cable. As such, when reconnecting the device to the legacy cable, the PS-10CC will also not know that it has been reconnected to the cable and will not update the LED status or priority charging order and power distribution.
- To resolve this, disconnect and reconnect the USB-C end of the legacy cable to the PS-10CC, which will let the PS-10CC know that the device has been reconnected. This will let the PS-10CC properly manage the priority charging order and power distribution.
It should also be noted that legacy devices also will inherently charge slower than most native USB-C devices with Power Delivery. This is because at most legacy devices can expect up to 5V 1.5A, 7.5W charging per the USB-C specification and power safety limits, while similar USB-C PD devices may charge at 15W or more.
Looking for more details? Check out our Plugable PS-10CC product page for specs and compatibility information, or our article about compatibility and general usage recommendations for the PS-10CC.
If you have any questions please feel free to contact us at support@plugable.com and we'll be happy to assist!
