2big Dock / d2 Thunderbolt 3 - USB 3.1 and Thunderbolt 3 Power Delivery

This article explains the Power Delivery options when the 2big Dock or the d2 Thunderbolt 3 is connected to a laptop using Thunderbolt 3 or USB-C 3.1

Power Delivery Specifications:

The Thunderbolt 3 ports on the d2 Thunderbolt 3 and 2big Dock Thunderbolt 3 can provide up to 15W of power.

USB-C 3.1 ports on these products can provide up to 27W of power.



When the 2big Dock’s, or d2 Thunderbolt 3’s power supply is plugged into an outlet, the LaCie storage device is able to provide power to a supported laptop that it’s connected to via Thunderbolt 3 or USB-C 3.1. For example a Macbook Pro or a Dell XPS.

Note: No power is provided when the USB 3.1 to USB 3.0 adapter cable is used.

Depending on the quality of the ports on the laptop, power requirements of the laptop, and the current activities being performed on that device, there are three effects this can have:

  1. The laptop charges as if it’s connected directly to an outlet, or slightly slower.

  2. The laptop doesn’t charge, but it also doesn’t lose charge.

  3. The laptop loses charge, but slower than if it was solely using its battery.



Not all Thunderbolt 3 and USB-C 3.1 ports are created equal. Some might be less efficient at receiving the power which the 2big Dock is delivering through those ports.

Some laptops require more power because of their internal hardware. For example the device might have a discrete Graphics Card.

Any extra device connected to the 2big Dock might require its own power, for example if a large external USB HDD is plugged into the Hub’s USB 3.0 port, this can limit how much power is available to the laptop.

Certain activities on a laptop might use up more power than the 2big Dock is able to provide, one example is using intensive video editing software.

Example: A 2016 Macbook Pro 15 inch with Touch Bar requires an 87W power supply. While it won’t always use the full capacity of that power supply, there are situations the Macbook Pro will be using a substantial amount. Therefore, during those situations, the LaCie 2big Dock’s, or d2 Thunderbolt 3's 15W (through TBT3) or 27W (Through USB-C) might not deliver enough power to charge the Macbook Pro efficiently.