9v 2a Charger Usb-c

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Smacka Shock

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Aug 3, 2024, 3:34:19 PM8/3/24

to inacypen

What about lower current chargers or portable batteries? It appears the Macbook attempts to draw at least 1.5A from its power supply. When it negotiates the power draw with the supply unit, and the power supply unit cannot provide the 1.5A at minimum 4.4-4.5V voltage, The Macbook discontinues its power draw. I found none of my 3 (cheap) portable batteries able to supply the Macbook, whereas a portable charger was able to charge the Macbook at 4.55V with 1.5A current.

The phone charger does charge it slowly when sleeping, maybe 10% per hour. But when awake I am can not tell if it charges as the battery seems to drain at the usual rate and in the power menu it says "power source - mains", "Battery is Not Charging".

I try to minimize the gear I carry, but even an iPhone adapter would add some hours during a whole day by decreasing the discharge rate. But remember that the macbook will increase the backlight when it receives power so maybe you end up with +/- 0 if you don't adjust the brightness. A high quality cable that is as short as possible also helps.

In some places I have read that you need to reach a certain wattage before it will charge, but in other places I have seen people talking about charging MacBooks from portable batteries through usb-a to usb-c, so this is at 5V and with only a couple of amps.

When charged with a 10W Apple charger, the Macbook draws 1.8A at 4.61V in my set-up, and reports a charge of 0.23mAh per second of charge in sleep mode. Thus a total charge would take about 6.5 hours (likely more due to the current drop-off near full charge). When watching a B&W movie in full screen mode, the 10W charger still provides enough power to charge the Macbook at a rate of 0.054 mAh per second, equivalent to a full charge in 27 hours.

What about lower current chargers or portable batteries? It appears the Macbook typically attempts to draw at least 1.5A from its power supply. When it negotiates the power draw with the supply unit, and the power supply unit cannot provide the 1.5A at minimum 4.4-4.5V voltage, The Macbook discontinues its power draw. I found none of my 3 (cheap) portable batteries able to supply the Macbook, whereas a portable charger was able to charge the Macbook at 4.55V with 1.5A current. To note, from an old iPod charger (5V/1A) the Macbook will draw 0.5A at 4.86V (my set up). Also to note, a small wall charger (Apple style) at close to max capacity will produce considerable heat.

From the official pi schematic, the usb-c specification (I am refering to table 4-24) and this post it seems that there are two 5kΩ resistors which tell the charger that the pi4 needs 5V.Is my assumption correct?

The charger you have asked about should be fine. The USB-C specifications allow the higher voltage levels, and a "signaling mechanism" that is part of the USB-C standard guarantees that as long as the device (your RPi) and the power supply both adhere to the standards, things will work as they should.

That said: The first RPi4 production units were "screwed up" - this was a design flaw that the Raspberry Pi Foundation eventually admitted. Since then, a revision/redesign has corrected the problem. It's worth noting that the original design flaw would not result in damage to either the supply or the RPi. Its only consequence was that a non-eMarked USB-C cable was required for the first production lot of RPi-4 - use of an eMarked cable resulted in no power to the RPi at all. Here's how to learn if your RPi-4 is one of the "affected" ones:

This question has come up here several times, and it has been answered several times: REF1, REF2, REF3. You will find copious amounts of detail here, but please feel free to ask anything that hasn't already been answered.

You mean power your Pi with a different USB C power converter. Yes it is possible to do this.With power adapters you must match the voltage output and the minimum amps the powered device will use or require. For a Pi this is the 5V/3A you have already mentioned. Any device you buy must meet this minimum requirement or you will face problems will stability of the Pi. Any other number for the voltage of the charger other than the 5V is not for your device.

If you follow that link and get to see the Canakit supply go with that. It works flawlessly with my Pi 4 and is rated 5V/3.5A a little extra for the power to be drawn from the supply. This is what the A tells you. 5V * 3.5A = 17.5W total power the 3A variety only 15W total to be had from it, the higher the A number the more power it is able to deliver without power supply overheating or shutting down.

I have tried a Xiaomi 1A1C 12V charger with 100W over USB-C. I also tried a UGREEN 65W charger supporting PD3.0. Both chargers don't work and the HP helper splash says, that the power is not enough for charging. What is required?

The other one appears to really be 60W for port C1 and C2, not sure why its not working. Perhaps the charger or it could even be the cable, I know linus tech tips did a video about how all usb-c cables are not the same and he can only get some to work with high power and only some to work with thunderbolt etc.

The manual you refer to on page 76 also says "The computer can operate on DC power within one or more of the following specifications. . The voltage and current for your computer is located on the regulatory label." Check to see what it is and then check your xiomi charger specs.

edit- there seems to be a lot of confusion lately on USB-C charging. I notice people often list the wattage as their primary concern. The USB-C spec has varying voltages also, off the top of my head it's from 5V to 25V. These are sensed by the charger where it adjusts if it can to the correct voltage.

Whatever I'm looking for a 100W USB-C charger working on 12V automotive voltage and working with the Zbook. As my Xiaomi phones already support 65W charging, I purchased their 100W charger thinking it could also charge the Zbook.

Now see there is more than one Xiaomi 1A1C charger and see the 100w car charger your talking about - I was looking at a house charger they make that happened to have max output of 12V x 2.25A so assumed that's was the 12V you mentioned.

The USB-C specs are odd - it only lists 20V-5A and not the full range like normal PD specs would - also lists the max total output as 68W for some reason. - ignoring those things I went looking for more answers.

As far as options, doesn't appear to be too many - Some that look like a typical laptop charger with brick in the middle amazn "HKY 100W USB-C Car Charger" - or another PWR brand one that comes up for more.