Question Can my Razer Blade laptop operate fully with lower wattage PSU than the original ?

[diapolical]

I ask because I am considering using a 65w usb-c charger with this laptop instead of the original Razer 100w charger when travelling and I want to know if that will limit what I can do on the laptop? In particular, will 4k video editing be hampered or even be impossible?

My laptop is a Razer Blade Stealth 13 (Early 2020) - RZ09-0310
The original PSU is a USB-C Razer 100w RC30-0310, which outputs at 5v 3a, 9v 3a, 15v 3a, 20v 5a.

Why does it output at 4 different voltages and which voltage is used for charging the battery?

This is a 100w charger, most usb-c chargeers for small laptops are 65w so why is this Razer charger more powerful?

Is the extra power (100w as opposed to 65w) to charge the battery faster or are there some resource intensive taks on the laptop, such as high frame rate gaming, or 4k video editing, that require the psu to be outputting at 100w?

Would a generic usb-c charger that can only provide 65w maximum provide the laptop with suffcient power under all circumstances?

It has been my experience over the years with using laptops that the most resource-intensive processing cannot be done on battery but requires the psu to be connected to the machine, though I have never seen anything posted on the net to corroborate this.

I have looked on the internet to try to understand USB-C power delivery but stil haven't found anything to answer my questions.

Your insight is appreciated.

 

[Fix_that_Glitch]

Look at your battery to see what wattage it puts out.

 

[hotaru.hino]

Looking at a review of the laptop, the power consumption can get up to 70W. So a 65W charger isn't going to work here. However, I'm sure there's probably something in the laptop that will still allow it to use a 65W charger, just it will do it at reduced performance. In any case, if you get one, I imagine three scenarios:

• The laptop won't use the charger
• It'll work, but the laptop won't charge and run at reduced performance
• It'll work, but the charger manufacturer cheaped out on safety, so the charger overheats and possibly catches fire.

To answer the other questions though:

The original PSU is a USB-C Razer 100w RC30-0310, which outputs at 5v 3a, 9v 3a, 15v 3a, 20v 5a.

Why does it output at 4 different voltages and which voltage is used for charging the battery?

USB-PD allows for several outputs. These don't output all at once, the device has to negotiate with the charger to determine what it wants and what the charger can provide. The laptop uses the 20V output, which you can get that info by looking at the bottom sticker.

The other profiles may be mandatory to include, because it's expected you'll be using it to charge/power another USB-PD based device.

This is a 100w charger, most usb-c chargeers for small laptops are 65w so why is this Razer charger more powerful?

Because the hardware is that powerful. Laptops with 65W chargers likely don't a dedicated GPU. Plus it has to be able to both supply power when the laptop is being used to its fullest and be able to charge the battery.

Is the extra power (100w as opposed to 65w) to charge the battery faster or are there some resource intensive taks on the laptop, such as high frame rate gaming, or 4k video editing, that require the psu to be outputting at 100w?

It's to be able to allow the hardware to be run at its fullest and charge the battery.

Would a generic usb-c charger that can only provide 65w maximum provide the laptop with suffcient power under all circumstances?

No, again pointing to the review I linked the laptop can consume more than 65W.

It has been my experience over the years with using laptops that the most resource-intensive processing cannot be done on battery but requires the psu to be connected to the machine, though I have never seen anything posted on the net to corroborate this.

Batteries have a maximum safe discharge rate, rated in terms of C, which 1C is the battery's capacity in one hour. While looking up some figures on the internet tell me lithium-ion batteries can safely discharge up to 10C, it also depends on the battery chemistry and how it was built. But a common rule of thumb I see is 1C.

So if we go with the 1C assumption, and given the battery in the 2020 Razer Blade 13 Stealth is 51W-hr, this means the battery can only provide 51W, which is lower than the maximum power that was tested to consume. Given the CPU is rated for 25W and the GPU 35W, that doesn't leave any room for the other stuff so they'll have to lower in power, or share a power envelope.

 

[diapolical]

Looking at a review of the laptop, the power consumption can get up to 70W. So a 65W charger isn't going to work here. However, I'm sure there's probably something in the laptop that will still allow it to use a 65W charger, just it will do it at reduced performance. In any case, if you get one, I imagine three scenarios:

• The laptop won't use the charger
• It'll work, but the laptop won't charge and run at reduced performance
• It'll work, but the charger manufacturer cheaped out on safety, so the charger overheats and possibly catches fire.

To answer the other questions though:

USB-PD allows for several outputs. These don't output all at once, the device has to negotiate with the charger to determine what it wants and what the charger can provide. The laptop uses the 20V output, which you can get that info by looking at the bottom sticker.

The other profiles may be mandatory to include, because it's expected you'll be using it to charge/power another USB-PD based device.


Because the hardware is that powerful. Laptops with 65W chargers likely don't a dedicated GPU. Plus it has to be able to both supply power when the laptop is being used to its fullest and be able to charge the battery.


It's to be able to allow the hardware to be run at its fullest and charge the battery.


No, again pointing to the review I linked the laptop can consume more than 65W.


Batteries have a maximum safe discharge rate, rated in terms of C, which 1C is the battery's capacity in one hour. While looking up some figures on the internet tell me lithium-ion batteries can safely discharge up to 10C, it also depends on the battery chemistry and how it was built. But a common rule of thumb I see is 1C.

So if we go with the 1C assumption, and given the battery in the 2020 Razer Blade 13 Stealth is 51W-hr, this means the battery can only provide 51W, which is lower than the maximum power that was tested to consume. Given the CPU is rated for 25W and the GPU 35W, that doesn't leave any room for the other stuff so they'll have to lower in power, or share a power envelope.

Thanks for the in depth reply. I've finally got the clarification I need.

I was suprised to hear the laptop only draws 70w maximum. Or have i misunderstood?

I already have a 65w gan charger and I have run the laptop on it. It does charge the battery and doesn't get very hot. Maybe it just won't last.

I haven't put the laptop through its paces on this charger, i havent edited 4k video with full resolution playback. Perhaps thats the condition under which it the charger would fail.

The 65w gan charger is much smaller than the original Razer version which is why it appeals for travelling. I have been wondering though if it might fail when I am editing video and in order to get a better idea about that I needed to know why the Razer charger had a higher wattage output eventhough a 65w charger was appearing to do the job. I apologize if my original post was a bit misleading.

 

[hotaru.hino]

The laptop drawed 70 watts in a game, which uses both the CPU and GPU extensively. If you're video editing or whatnot, that only tends to load the CPU for extended periods of time.

You're probably fine with the charger you got, but if it feels too hot to hold uncomfortably, you risk running it to the ground at that point.

 

[diapolical]

The laptop drawed 70 watts in a game, which uses both the CPU and GPU extensively. If you're video editing or whatnot, that only tends to load the CPU for extended periods of time.

You're probably fine with the charger you got, but if it feels too hot to hold uncomfortably, you risk running it to the ground at that point.

Thanks again ... that makes sense to me, that only certain parts of the video editing process load the CPU so heavily