1

If this is not the right place for this question, sorry and please direct me to the right place!

I have a Dell Precision 5540 laptop, which has a 130W AC Adapter.

Input = 100-240v~1.8A 50-60Hz

Output = 19.5V == 6.67A

I wanted a docking station to plug in all my peripherals and so got a Belkin Thunderbolt 3 Dock Pro. However, I did not consider the charging. I believe the docking station is capable of charging a laptop however, when I plug it into mine, I get a notification on screen stating the laptop is not being charged. This is fine with me because it's easier for me to plug in my external laptop charger than order a new "compatible" docking station.

According to the charger brick that came with the docking station, the power specs are as follows

Input: 100-240V~2.5A 50-60Hz

Output: 20V == 8.5A

My question is this -- Is it dangerous to plug in my docking station AND my external laptop charger to the laptop at the same time? Although the laptop does not get charged with only the docking station plugged in, I assume it's still receiving the power. Along with my external charger, I am afraid it may be receiving way too much power? I know nothing about this topic, please correct me if my assumptions are wrong. Many thanks! :)

Improve this question
4
  • I don't have a specific answer, but there are likely some ACPI settings in the BIOS which might allow you to disable charging on Thunderbolt. Alternatively, do a Google search for "disable charging via thunderbolt 3".
    – spikey_richie
    Commented Nov 30, 2020 at 11:21
  • I know nothing about "Belkin Thunderbolt 3 Dock Pro" but for "Dell Dock WD19" the Quick Start Guide states that: Note under figure 4: > "NOTE: Computers requiring more than 130 W power input must also be connected to their own power adapter for charging and operating at full performance." So for my type of docking station it is even required if computer should work at full performance.
    – digital_infinity
    Commented Nov 30, 2020 at 11:26
  • @digital_infinity the OP's issue though, if that the laptop will end up receiving power via the mains charger AS WELL AS via the Thunderbolt port.
    – spikey_richie
    Commented Nov 30, 2020 at 11:36
  • Good points. From the documentation that @digital_infinity mentioned, I assume they intend for chargers to be plugged into the system in such cases. But yes, if anyone here knows for sure whether having both plugged in is dangerous, please do let me know.
    – Izy-
    Commented Nov 30, 2020 at 21:23

1 Answer 1

Reset to default
1

My question is this -- Is it dangerous to plug in my docking station AND my external laptop charger to the laptop at the same time?

No, it is not dangerous to plug in your docking station and your external laptop charger to the laptop at the same time. Your laptop's power delivery will have onboard power sensing and switching and should be designed to prevent contention between sources. It is designed to draw from the source which provides more power (usually the power brick) and cut off the other.

On top of that, Thunderbolt has a protocol/handshake and power negotiation too, and even if this fails or if the other end of the Thunderbolt port is "dumb" (i.e. does not support power delivery negotiation) then you'd still have the laptop's onboard power delivery management.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .