For you, what makes it better than using a 100W or 200W small AC-DC 50.4V CC/CV power supply and a beefy connector direct to the BMS/pack?
For both USB and the above method you need an AC-DC power supply (USB charging adapter or CC/CV supply) and a connector.
The USB method however also requires a boost converter to bring the voltage back up after the USB adapter brings the voltage down and USB connectors are notoriously delicate and hard to keep protected.
I was originally really up on charging via USB-PD but after thinking about it I don’t see any benefits. Hoping to be enlightened though!
The ideal use case for me would be a Backfire mini -type board with a USB C port so I can carry just one charger ever. I do a lot of skating around my small city, I often carry my laptop charger and my backfire mini charger.
Another probably easier thing to do is integrate the charger into the board and have a retractable power cable or something
I think the main goal of type-c charging (at least for me) is to only use one charger.
With the ubiquity of type-c we’re now charging our phones, laptops, earbuds, cameras and other accessories with type-c and now at even higher power levels with USBPD.
The imagined use case is riding one’s board to Starbucks, plugging it in while you work on your laptop, riding to your friend’s place, plugging in your laptop with the same cable, then going to sleep after swapping that same cable to your phone. Then use the same cable to charge your headphones and camera in the morning.
MOSFETs, current sense resistors, diodes…probably anything in the main current path(s). If it also has a linear regulator, in addition to what looks like a switching regulator, that could get hot if the input voltage was at its high end limit.
I thought about USB-C charging some time ago (just recently joined the forum) after a bit of research and thinking concluded a few things from my POV.
It would need to be able to accept any USB-C power input, from any $5 wall brick to a $70 laptop charger being USB-C being the key physical standard, not the watts/volts/amps.
To achieve point one, converting the incoming power in some way will always be necessary. And further the converter would likely be best wired inside the board/scooter/bike itself as a sub charging system.
Even with one and two accounted for, in best cases the charger would be fair, in most cases not more than a trickle charge.
An interesting option maybe would be using the USB-C physical standard but Frankenstein charging setup. This is a bad idea but using some form of a break-out board, then just splitting the normal charging +/- to matching pins. (Not sure if the PCB traces could even handle the power levels it should be able to?)
It would technically be swapping out the two charging points, like swapping from barrel to XT60 or whatever. By no means would you want to plug this in to a normal device(instant death I am sure) but it would look clean and be simple to plug in.
This is going to be highly inefficient by nature. Not to mention. Charging at 100W will draw 20amps on the 5v side lol. Not accounting for efficiency losses. Maybe you’re gonna charge at a lower wattage then maybe. But that’s gonna be sloowwww.
Looks like the next generation of PD chargers will be 140W, 28V at 5A. Not bad but certainly not 240W. The USB-C PD controller chips for devices accepting PD charging, when released (no signs yet), will probably also be limited to that power level.
I don’t think we’ll see those 240W power levels until the end of the year, if that soon. Just too many things to address and get right before 48V/5A can be safely and reliably used in a USB-C connector and cables. The chargers will be massive too until they get the GaN tech (which shrinks charger size) tweaked well enough to make them affordable.
