Strange behavior with 90W Dell Charger

[ArduinoBen]

I have the origional top spec model of the Xiaomi Mi Notebook Pro with a i7-8550U, MX150 and 16GBs of RAM, which only ships with a 65W charger.  Unfortunately, the components draw too much power, meaning that when I'm gaming while plugged into this power supply I will slowly lose power.  Therefore I bought a 90W USB-C Dell charger last week, and tried that one out.  It turns out this charger charged my laptop even slower, with it requiring around 6 hours to charge my laptop when it was idling instead of less than 2 with the OEM charger.  Additionally, when gaming it very quickly loses power, with my full battery fully depleted after just half an hour of gaming.  

 

My only idea to what could be causing this would be if the computer wasn't communicating for the right amount of power to be supplied to it, as USB-C is universal and I've been told that the device being charged will measure temperatures and such to determine what voltage and amperage it should ask to be supplied, and when nothing was communicating the charger would default to supplying the lowest amount of power it is capable of in order to avoid damaging the device being charged in case it wanted very little power, therefore my laptop could not be communicating properly with the charger, causing the charger to send less power than it was capable of.  Do any of you have an idea of what the problem is or how I could fix it?  My dad tried it with his Dell laptop and said it worked well, and I'm going to try and record the charging speeds of his laptop with this 90W charger compared to the speeds with his OEM 65W charger.

[NeuesTestament]

Is the amount of power delivered by the charger constant during the whole charging process or is it higher at first and then drops off?

[genexis_x]

I believe that that model doesn't support USB C charging

[ArduinoBen]

On 12/4/2018 at 11:21 PM, GeneXiS_X said:

I believe that that model doesn't support USB C charging

USB-C is the only charging port I have on my laptop.

[genexis_x]

17 minutes ago, ArduinoBen said:

USB-C is the only charging port I have on my laptop.

Oops, sorry I remember wrongly

[Canada EH]

On 12/4/2018 at 1:10 AM, ArduinoBen said:

Unfortunately, the components draw too much power, meaning that when I'm gaming while plugged into this power supply I will slowly lose power.  Therefore I bought a 90W USB-C Dell charger last week, and tried that one out.  It turns out this charger charged my laptop even slower, with it requiring around 6 hours to charge my laptop when it was idling instead of less than 2 with the OEM charger.  Additionally, when gaming it very quickly loses power, with my full battery fully depleted after just half an hour of gaming.  

 

My only idea to what could be causing this would be if the computer wasn't communicating for the right amount of power to be supplied to it, as USB-C is universal and I've been told that the device being charged will measure temperatures and such to determine what voltage and amperage it should ask to be supplied, and when nothing was communicating the charger would default to supplying the lowest amount of power it is capable of in order to avoid damaging the device being charged in case it wanted very little power, therefore my laptop could not be communicating properly with the charger, causing the charger to send less power than it was capable of.  Do any of you have an idea of what the problem is or how I could fix it?  My dad tried it with his Dell laptop and said it worked well, and I'm going to try and record the charging speeds of his laptop with this 90W charger compared to the speeds with his OEM 65W charger.

If you draw too much power, the Dell charger will shut down. Just unplug the Dell charger, plug it back in and good to go. The charger is a 3 wire charger, meaning the middle pin is a communications pin, OneWire Protocol. I guess when that pin touched the inside + the chip is fried. If its 90W and its 19.50V then its only 4.5A of charge, depending  on battery size it can take some time. There are more powerful models, like the 130W Dell 19.50V 7.5A that I can buy for C$15 all day long. There is one model up from that with more wattage, I do believe, I could be wrong. I believe "my guy" told me 170W. I say hey doood keep an eye out, I will buy!

 

The OneWire Protocol could be your problem. I believe the OneWire chip in the laptop fries commonly.

 

Could also just be a defective charger.

 

Also see how much power you are running. Get a wall outlet power meter, $20 off amazon, next day shipping. Could be worth your while to investigate while on pc.

 

You see, if the charger pushes out too much juice into the desktop, it shuts down. Voltage goes to zero. I have seen it with my own eyes, metered it with the 130W Dells. The chargers do get hot, but 45C is common (right at the main transformer coil), not sure what amps its pushing as I got other problems to deal with. To deal with it shutting down, I hacked the charger. But its a totally different area then running a pc. Also, dont ask what I am doing with my chargers but I have lasered it at 65C and sometimes up to 75C. Again at the main transformer coil, which side, cant say because I dont pay attention, I believe its output side, middle, 3" from end.

 

There are only two 3 wired fets that have metal cooling attached. A shit ton of white stuff, not hard to take off. But enough, not filled up all the way. The heat sinks are positive, unique engineering design.

[ArduinoBen]

7 minutes ago, Canada EH said:

If you draw too much power, the Dell charger will shut down. Just unplug the Dell charger, plug it back in and good to go. The charger is a 3 wire charger, meaning the middle pin is a communications pin, OneWire Protocol. I guess when that pin touched the inside + the chip is fried. If its 90W and its 19.50V then its only 4.5A of charge, depending  on battery size it can take some time. There are more powerful models, like the 130W Dell 19.50V 7.5A that I can buy for C$15 all day long. There is one model up from that with more wattage, I do believe, I could be wrong. I believe "my guy" told me 170W. I say hey doood keep an eye out, I will buy!

  

The OneWire Protocol could be your problem. I believe the OneWire chip in the laptop fries commonly.

 

Could also just be a defective charger.

 

Also see how much power you are running. Get a wall outlet power meter, $20 off amazon, next day shipping. Could be worth your while to investigate while on pc.

I'll look into the 130 Watt model but I think it's most likely a defective charger.  I'm going to try recording the charging speed using this charger with my father's Dell laptop versus the 65W one his laptop came with.  Also, I have tried this charger in multiple outlets and my laptop still charges as it used to with the OEM charger, so I don't think my laptop has been damaged.

[Canada EH]

You have to know the Wh of your battery. Should say on it.

And the charging curve is not linear, its a cc and cv charge curve.

Its a good estimation though.

 

Example

10Ah battery at 10A should take about an hour, give or take.

 

Depends on factors, like how drained the batteries are.

What is the low voltage cut off.

Many factors, what chemistry cells they are, different voltages of chemistry batteries, different Ah, pouches, 18650, 26650 form factors

Lots of Factors!

 

Two things you should be concerned about.

How much juice the charger is accepting from the wall.

How much juice the charger is pushing into your laptop.

 

Can only cut the wire and measure on the output of charger.

Meter the wall outlet with the plugin meter (consumer grade) or cut wire and use digital meter.

If you have one digital meter, good. Two meters is the sign of a dood whom knows whats going down. Measure battery voltage. Get the voltage of battery, wh of battery. Measure with digital multi meter. $10 from RadioShack, free from Harbour Freight.

 

 

6 minutes ago, ArduinoBen said:

recording the charging speed