USB-C Charging Laptop

[PhilC]

I have been looking at a laptop to use aboard that is charged through a USBC. I was thinking that I could avoid the use of DC >Inverter> AC chargers > DC charging and the losses that come with that. However there seem to be some challenges for example USB-C power outlets I can source seem to be limited in power output to a level suitable for charging phones not laptops. Seems that USB-C delivers up to 18v, as I have a 24v house system I would be stepping down voltage for this but outlets I have found seem to be designed for 12v input.
Anyone gone down this path? Any advice?
Phil

[PhilC]

Please note I am referring to USB-C
https://en.m.wikipedia.org/wiki/USB-C
This is standard charge and data transfer format for many new devices.

[jack4566]

@thomm225 USB-C is not just 5V anymore. The USB PD spec allows for power boosting up to 20V@5A. Lots of laptops these days use USB PD with 65W chargers.



OP you can't not just boost the voltage to 20V wire it up and call it done. You need the specific USB PD protocols so the charger can talk to the laptop. What I would suggest is looking for a 65W USB car charger. Something like this. Then you can wire it in how you like. I think trying to find one that is 24V input would be near impossible. Im sure you already have 12V step down for other electronics. These things are 92+% efficiency your not losing much.
You do NEED to ensure that the charger is 65W compatible.


Personally all my devices are USB-C now and its awesome. No more fussing around for different chargers or using inverters.


EDIT: 2 seconds on google lead me to this 24V unit: https://www.coolgear.com/product/usb...charger-ccg3pa
Protip: when buying chinese ****, buy 2 or have a backup plan.

[PhilC]

@jack4566 how efficient is the 12 charger? Presumably it is stepping up the voltage from 12 to 18 when charging at 65watts. Also are you charging a laptop with only 65watts? What make / model works with this . Can it keep up at 65 or do you gradually run it down then charge up when not using?

[jack4566]

I dont have that specific model it was just an example.

I have the Levono ThinkPad E590. It came with a 65W charger.
65W is what most laptops with USB-C use. Just look at your laptop charger and the rated wattage should be listed. If you dont have a laptop right now the specs should list it as a USB-C charger 65W most likely.

65W is the MAX supply, the device will dictate how much power is actually drawn. If i plug in my phone it will only draw 12W for example. Once charged my laptop only draws about 10W doing light work.

[triibutu]

A modern laptop uses well below 10 watts at usual browsing the net tasks.
I'm just about to replace the regular usb sockets with some of these: https://www.aliexpress.com/item/1005002050625682.html
Mostly for charging phones and tablets, but it also charges my Thinkpad T480s just fine. The laptop reports the USB-C as 30 watts power supply, so I guess the claimed 60W is sum of the 2 outputs, but 30W is plenty enough for me.

[triibutu]

Originally Posted by jack4566

You do NEED to ensure that the charger is 65W compatible.

Not really, but may depend on the laptop.
My T480s happily charges off a Samsung S20 phone charger @ 24W

[jack4566]

Interesting. My machine wont charge unless its a proper 65W rated charger. I suspect it needs the 20V you only get with the higher profiles.


See the chart on the right here for all the different profiles.

[Fortytwo]

https://www.amazon.com/dp/B08QZ7RTSW...A0FG8ZNPGY791B

https://www.amazon.com/dp/B00K0TQ94C...ing=UTF8&psc=1

Mounting the cigarette type plug, you can use/change/update to whatever adapter you need.

[PhilC]

Originally Posted by Fortytwo

https://www.amazon.com/dp/B08QZ7RTSW...A0FG8ZNPGY791B

https://www.amazon.com/dp/B00K0TQ94C...ing=UTF8&psc=1

Mounting the cigarette type plug, you can use/change/update to whatever adapter you need.

I’m not a big fan of cigarette lighter outlets. Especially if drawing 65w, tend to be high resistance connection. Would much prefer to hard wire in a USB-c outlet like the one linked above. Thanks @jack4566

[Dsanduril]

We use this one (I see Amazon says not in stock) specifically because it has a dual voltage input. Work from 10-15VDC and from 20-30VDC. We have 12V (nominally) on the boat, and I work in a lot of control panels in the field with 24V power. The operating ranges cover most charging voltages unlike some narrower input devices.

First thing I did was cut off the cigarette lighter plug. Have bare leads that connect to terminal blocks as I move it to different locations.

[DanielI]

I had pretty good success with this one:

https://powerwerx.com/panel-usbc-pd-...very-qc30-blue

Input voltage is 5-32V. Output is only 18W, but it supports a lot of protocols. I think many devices will charge at different rates depending on the input. So, depending on the laptop, this may work but charge slowly. As I recall, I was able to charge a laptop overnight with this. I did look for one with higher wattage, but this was the highest I found.

[CaptTom]

Originally Posted by triibutu

I'm just about to replace the regular usb sockets with some of these: https://www.aliexpress.com/item/1005002050625682.html
Mostly for charging phones and tablets, but it also charges my Thinkpad T480s just fine. The laptop reports the USB-C as 30 watts power supply, so I guess the claimed 60W is sum of the 2 outputs, but 30W is plenty enough for me.

Nice find! I really like the on/off button on the face. Others I've seen don't have that. On a boat we don't need parasitic loads.

Also, good to know the T480 works on these. I'm about due for a new laptop and the ThinkPad line is the only one which still supports the little "pencil eraser" mouse pointer which I've gotten used to.

[triibutu]

Originally Posted by CaptTom

Also, good to know the T480 works on these.

Note I wrote T480s and not T480, they are internally quite different. Charging from low power sources may or may not be different between the two, for example some laptops only charge from low power when asleep. I have no personal experience with a T480.

[dfelsent]

USB-C Laptop CAR Charger Power... https://www.amazon.com/dp/B003FOOY32...p_mob_ap_share

I bought one of these last summer. It runs my laptop well, and seems to have plenty of oomph.
Claims up to 90 W, I needed a 65W charger.