diy solar

diy solar

Wanted: 12VDC to USB-C 3A device

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
Joined
Oct 29, 2019
Messages
7,699
Location
Rural NE Ontario Canada
There isn't a "wanted section". Why not look on eBay, Amazon & Ali* ? I did.

I looked but it's an overload of stuff and I have a specific need and am hoping someone here has it or knows a Good Quality source for the device.

I need to take 12V which comes from a small 12V subpanel and wire it to an adapter that will prove a USB-C power @ 3A per socket, for a total of 6A if dual.
Not a Cigarette Lighter plug thing. Wired & mountable, reliable & durable. It is to run a Raspberry Pi 4B that will be the "intermediary" and running my monitoring & management tools of my solar system. Therefore it's "fairly critical" and will run 7/24/365.

There is so much and "looks good on screen" but not so much in reality, hence why I'm asking.

Thanks in Advance
 
This is a 2 port rated at 4.8 amps, but I'm not sure if thats 2.4 amps per port or a total of 4.8 whether one or two is plugged in.


I'm have plans to install 4 of these in my RV, not for the extra amps that a USB C provides, but for multiple cell phones and ipads.

I also wonder if the USB 3.0 chargers that deliver at 36 watts comes close to the 8 amps you want. Once stepped down to 5 volts, the 36 watts is about 7.5 amps.
 
Last edited:
This is a 2 port rated at 4.8 amps, but I'm not sure if thats 2.4 amps per port or a total of 4.8 whether one or two is plugged in.


I'm have plans to install 4 of these in my RV, not for the extra amps that a USB C provides, but for multiple cell phones and ipads.

I also wonder if the USB 3.0 chargers that deliver at 36 watts comes close to the 8 amps you want. Once stepped down to 5 volts, the 36 watts is about 7.5 amps.
Those Blue sea ones seem really expensive.
I have actually been doing a lot of testing with USB-C chargers it seems the only way to get the watts up is to increase the voltage. For example my 20 Ah Power brick charges at 1 amp and 9 volts where a phone charges at 5 volts and up to 1.5 amps. I have tried every configuration possible to see the most watts I could get.
 
we all have the same idea


The new high current USB devices require the accepting item (charg-ie) to comunicate with the charg-er. "charg-ie; hey charger, i can take 3A. charger - confirm you can do 3A, charg-ie - confirmed" 3A given. if the above communication does not occur you get standard 1.2 amp (ish)

what you likely want is something like
 
Those Blue sea ones seem really expensive.
I have actually been doing a lot of testing with USB-C chargers it seems the only way to get the watts up is to increase the voltage. For example my 20 Ah Power brick charges at 1 amp and 9 volts where a phone charges at 5 volts and up to 1.5 amps. I have tried every configuration possible to see the most watts I could get.

I did not know that the charging voltage would go up to 9 volts. If some devices require that many volts when charging, I can see the need for some sort of communication so all the lower voltage devices do not have too many volts dumped into them.
 
I did not know that the charging voltage would go up to 9 volts. If some devices require that many volts when charging, I can see the need for some sort of communication so all the lower voltage devices do not have too many volts dumped into them.
I am not positive but it seems as if the devices will hold the voltages down as necessary. I plugged a 5v device into an 12v outlet and volts stayed at 5 amps were .5
 
we all have the same idea


The new high current USB devices require the accepting item (charg-ie) to comunicate with the charg-er. "charg-ie; hey charger, i can take 3A. charger - confirm you can do 3A, charg-ie - confirmed" 3A given. if the above communication does not occur you get standard 1.2 amp (ish)

what you likely want is something like
Good find!
 
Just a heads up in case it has not already been covered. USB-C is not all one thing

I believe USB-C is the spec for the physical port.

Beyond this is there is USB-C PD, I won't go into detail but this is what many modern mid to high end smartphone, tablet, and ultrabook + macbook chargers use. It can deliver upto 100W @ 5v, 9v, 12v, 15v or 20v. Not all Power Delivery chargers or devices can supply all of those voltages or the full 100W (most can't) but they use the same protocol to intelligently determine the correct voltage, and can be used with multiple devices even with different voltage batteries and different power max charge rates.

One random explainer on the standard
 
Last edited:
Excellent, I knew someone here would likely have something up there sleeve and sure enough Voila !
Geez, I love this site. what a Great Gang of Sun Lovin Folk ! ;-)

I presently have a Raspi 3B+ but getting the 4B which demands a tad more juice than the 3B
The official Raspberry Pi USB-C power supply is designed to power the latest Raspberry Pi 4 Model B boards, which were released in June 2019.
  • 5.1V / 3.0A DC output
  • 96-264Vac operating input range
  • Short circuit, overcurrent and over temperature protection
  • 1.5m 18 AWG captive cable with USB-C output connector
Some vendors are providing 3.5A power supplies with their kits, I imagine that is to help support SSD's and other attached extras.
I was looking at BlueSea's offering as I have no doubt they are good quality but figured it's better to ask those who are using such, I've been leary of these little converters as I had problems with them a few years ago (1 burnt car).

I only mentioned the Dual Port because they seemed to pop up a lot, I don't have a need for dual as I'm only going to power one Raspi4B.
I was considering the idea of powering this from the 24V Bus Bars directly but the device would have to be able to take the charging voltage which worried me as I discovered some step-down converters won't tolerate that. Then I discovered the better ones that can take up to 30V and not stress, damned Fine Print.
 
Great. Just great. Now something else to buy and put into my system! :) 24V and an easy recharge option for devices!
 
Just a heads up in case it has not already been covered. USB-C is not all one thing

I believe USB-C is the spec for the physical port.

Beyond this is there is USB-C PD, I won't go into detail but this is what many modern mid to high end smartphone, tablet, and ultrabook + macbook chargers use. It can deliver upto 100W @ 5v, 9v, 12v, 15v or 20v. Not all Power Delivery chargers or devices can supply all of those voltages or the full 100W (most can't) but they use the same protocol to intelligently determine the correct voltage, and can be used with multiple devices even with different voltage batteries and different power max charge rates.

One random explainer on the standard
USB power is clearly becoming a lot more sophisticated and that’s a useful explainer document. I’m planning to deploy some USB sockets wired in parallel and fed from a 12V to 5V XL4006 module with current limiting function and I now realise that this won’t support the maximum charging rate on some of the more modern devices.

It will be interesting to hear from forum members who have found reliable step down modules which provide support for usb-C and USB PD 3.0, as it seems the only way to deploy these in the home will be to make use of ready made modules rather than trying to wire your own USB sockets in the slightly old fashioned way I’ve been proceeding with.
 
  • Like
Reactions: Dzl
USB power is clearly becoming a lot more sophisticated and that’s a useful explainer document. I’m planning to deploy some USB sockets wired in parallel and fed from a 12V to 5V XL4006 module with current limiting function and I now realise that this won’t support the maximum charging rate on some of the more modern devices.

It will be interesting to hear from forum members who have found reliable step down modules which provide support for usb-C and USB PD 3.0, as it seems the only way to deploy these in the home will be to make use of ready made modules rather than trying to wire your own USB sockets in the slightly old fashioned way I’ve been proceeding with.
There are some interesting videos on youtube of people playing around with the USB-PD spec. Great Scott has a few videos on it. I have also recently come across 'cool gear' which cells many different USB gadgets, chargers, and PCB's including a few USB-PD charger PCB's and packaged chargers which might be useful to you. Input voltage is 12-24V (its not clear whether that is the actual voltage range or whether these devices will work with 12v and 24v nominal systems)

These devices are based on the Cypress chip which I had discovered a while back and looked good, but couldn't find any actual PCB's for sale retail that used it.

What i want to find now for my current project I'm working on is a PCB that will allow bi-directional (source / sink) current from the same port or at least the same board like many modern power banks use.
 
There are some interesting videos on youtube of people playing around with the USB-PD spec. Great Scott has a few videos on it. I have also recently come across 'cool gear' which cells many different USB gadgets, chargers, and PCB's including a few USB-PD charger PCB's and packaged chargers which might be useful to you. Input voltage is 12-24V (its not clear whether that is the actual voltage range or whether these devices will work with 12v and 24v nominal systems)

These devices are based on the Cypress chip which I had discovered a while back and looked good, but couldn't find any actual PCB's for sale retail that used it.

What i want to find now for my current project I'm working on is a PCB that will allow bi-directional (source / sink) current from the same port or at least the same board like many modern power banks use.
Thanks @Dzl - that online store does look like a treasure trove of useful bits for us power electronics tinkerers. Shame it’s in the states, as importing into Europe always attracts additional costs.

For now I’ve ordered some cheap car adapters which have QC3.0 and USB C PD ports, which I will de-case and integrate the PCBs into the underside of my living room table. Despite the low price point, they do seem to offer fast charging according to the amazon reviews, so hopefully a bargain rather than cheap rubbish.
 
  • Like
Reactions: Dzl
I have also recently come across 'cool gear' which cells many different USB gadgets, chargers, and PCB's including a few USB-PD charger PCB's and packaged chargers which might be useful to you. Input voltage is 12-24V (its not clear whether that is the actual voltage range or whether these devices will work with 12v and 24v nominal systems)
Man, I could spend a TON of cash in that store!

Running away now before my wallet hides from me!

Thanks for the link.
 
If using a 5V DC converter to provide power to USB 2.0 style sockets, is it necessary to arrange for current limiting to 500mA (or 900mA), or can you safety hook up a 5V 9A (Max) buck converter module to a USB and assume that any USB device connected will self-limit the current and not damage itself by drawing too much current?

I’m thinking particularly of devices with small 1S lipo batteries which recharge from USB, which maybe don’t have good charge circuit protection and perhaps rely on the assumption that the USB socket supply will limit the charging rate.
 
The specifications on that web page don't say what the standby power draw is. Any idea?
Not sure, the only power efficiency info I see is (from what I believe is the newer version product page):
Meets new energy efficiency requirements of DOE Level VI – the highest energy efficiency rating.
I don't know anything about "DOE Level VI" other than that it appears to be an efficiency standard from the US Department of Energy that relates to chargers and applies to both active use and idle.

edit: I have asked for datasheet for 3 models, we will see what comes of it. I also got some clarification on voltage:
The product is compatible with any voltage from 12 through 24v DC, officially. Unofficially we know these will be used in battery powered systems, so the real tolerance is closer to 10~27v DC
 
Last edited:
Back
Top