So I am inferring this from limited public data and so I’m seeking something more definitive. I am just curious as to the electronics.
Hypothesis:
QC ports have a fixed Wattage budget dedicated to each port. If that Wattage dedicated to a port is not being used, then it cannot be used for other purposes, such as it cannot be used for a non-QC port.
Evidence:
https://www.anker.com/products/A2054111 (and the Amazon link)
So what I’m seeing is:
- the non-QC ports have “PowerIQ Output :5V=4.8A (2.4A Max Per Port” so implies a fixed 24W budget spread across the 3 non-QC ports, and these non-QC ports share that budget so e.g. plug in 3 tablets each wanting 2A for 6A you’d find them charging slower receiving 4.8/3 1.6A, even if the QC ports are not using their 36W
- the QC ports have no mention of sharing they just state each port is “Quick Charge 3.0 Output :3.6-6.5V=3A, 6.5-9V=2A, 9-12V=1.5A” so with the above it implies inside this product there are in fact 3 isolated power budgets. Each QC port has ringfenced power budget, and the non-QC ports have pooled budget.
- QC3 is supposedly 19.5W so 2x19.5+24=63Watts
Problem:
- If this is true it means you’re not able to use all of the 63W you are paying for unless you use all of the QC ports (in this example 2 ports) and at least 4.8A from the other 3 non-QC ports.
Why this matters:
- Cost, weight
- Cost because you’re paying for 63W of power but you can’t use it all. If those 3 PowerIQ ports were each used with a device capable of consuming 2.4W you’d usually help those devices using 2.4x5x3=36W but they share 4.8x5 24W, the 39W of the 63W for the QC ports is not accessible to you, so your non-QC devices suffer needlessly.
- That ringfenced budget is a cost of a higher wattage total
- Higher total power budget is a physically larger device.
Contrast with the non-QC multiport devices, for example (which is not available presumably due to more USB-C stuff coming soon)
This non-QC multiport example has a total budget of 40W and the non-USBC ports share the same power budget (8A,5V, 40W) it isn’t (unlike QC ports) less for the non-USBC port due to the presence of the USB-C port. If Anker did same as in QC+non-QC port charger, the presence of that 5V 3A 15W port from the 40W would leave 25W so 5A total shared but it says 8A shared.
The non-QC example is wasting nothing, the total wattage is shared across all ports, so you could not use that USBC port at all and all 40W can be consumed by the other 4 ports e.g 4 2A capable devices each capable of pulling 10W would all get 10W each as 10x4=40W the total budget.
So Anker, why is this? Is this because of licensing cost issues? Or is the negotiation phase of QC where it detects and negotiates a one-time thing so you can’t post-connecting then reduce the QC power to share with the others? It makes no sense, it is not efficient.