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A Lenovo P16 laptop with a NVIDIA RTX 4000 can use up to 230 W power. The proprietary barrel power supply can provide it, but a standard USB-C docking station only provides about half of that.

If I intend to use the GPU at full power, do I need to buy a docking station that provides 230W+ USB-C? Does such a thing exist? Or do I need to keep the barrel charger in also?

Is it possible to not use the barrel charger, and for the laptop to draw the extra power from the battery, which will charge slowly from the docking station (of course, this will only work if I use the GPU for only short periods of time).

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You'll need to use a barrel charger or allow the battery to drain down

The Lenovo P16 Gen 2 with the RTX 4000 supports USB PD 3.0, which maxes out at 100W (20V/5.0A). While there are USB-C chargers that can supply up to 240W (48V/5.0A), these chargers are using the newer USB PD 3.1 spec, and the Lenovo P16 Gen 2 won't be able to draw the full 240W even if you get one of these chargers.

As such, you'll need to either use the slim-tip charger, or to rely on the battery when at peak load. For day-to-day use, you probably won't be drawing 230W continuously, so the latter is probably fine; however, you'll definitely want to make sure you have the slim-tip charger on-hand for when you need it.

Aside: there are adapters that will let you use a USB-C charger with a slim-tip computer; however, they appear to max out at 100W currently. While higher-wattage versions may come later on, I wouldn't necessarily count on it.

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  • Thanks. Assume my typical power draw is 75W, but I occasionally go to 230W. Is it correct that when at 230W, the battery can fully provide it, so I'll have all the power I need then? And is it correct that, during the other times, when I'm only using 75W, the USB will charge it (although very slowly - less than 25W of charge)? Commented Apr 1 at 14:59
  • Typically yes, most laptops are designed such that they can run at full power off of battery. Some laptops do throttle their performance by default when on battery power for battery life reasons. Typically this can be configured, though you may have to adjust some settings. However, I wouldn't expect that situation to come up since you'll still be on wall power, just less of it. And yes, your battery will charge as long as you're drawing less than the power supply is supplying.
    – JMY1000
    Commented Apr 1 at 18:53

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