I have a Dell Precision 7750, which has a strong GPU, and therefore a power adapter with 240W.

When I'm on the road, I need to charge the laptop with a power bank. My power bank is 65W.

I want to charge the computer, even if it is very slow to charge. I don’t want to run the GPU when doing this, so probably the computer does not consume 240W but much less.

When I plug the power bank via the USB C Thunderbolt 3 connection, nothing happens, and warning comes up that the PC is not charging.

What can I do?

  • It seems like the Dell Precision 7750 supports power delivery — which would allow it to charge via the USB C connection — but 65W is about 3.5 times less 240W. In my experience with MacBooks, you can always plugin power adapters that provide less wattage but they won’t do much. I have a MacBook Air that needs at least 29W power to share but if I plug it into an 18W adapter I get a similar “not charging message.” I would say you need at least an 240W USB power adapter to do what you wish to do. Jan 6, 2021 at 19:00
  • 2
    What happens if you turn the computer off, and try to charge it then? It then doesn't consume any power, so may change slowly then.
    – LPChip
    Jan 6, 2021 at 19:17
  • Not all chargers are compatible with all laptops : link.
    – harrymc
    Jan 6, 2021 at 19:41
  • 3
    The 65W charger may overheat, an experiment on your part.
    – Moab
    Jan 6, 2021 at 19:54
  • 1
    @BestR (Cont'd...) That being said, it's unwise to try and power a device from a power source that doesn't meet the minimum wattage required by the device, as this thermally stresses the power source (e.g. if using the power bank with the laptop on, it would be best to only use the integrated graphics in lieu of the discrete GPU, and to continuously monitor the heat output by the power bank to ensure it doesn't get hot to the touch from the higher impedance that occurs when trying to pull more current than a power source is able to output)
    – JW0914
    Jun 29 at 11:03

1 Answer 1


I'm using 90W small Dell charger when travelling and it covers the needs without problems. If you are not 3D modelling too much or doing stuff that requires high CPU usage, the 90W charger is enough to feed the laptop and also to charge attached phone. With 65W charger, which is only a bit smaller than 90W version, sometimes the battery level goes down as it is not able to fully cover the running laptop. On the other hand if you are only browsing internet, dealing with emails and you keep your screen on low level of backlight and select system behavior to "energy saving" setting, then even the 65W charger will be enough for you.

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