The best time to download heavy files is at night. Because during the day, you need the bandwidth to do your own work. A Raspberry Pi is ideal for downloading. It doesn’t consume lots of power. It can be plugged directly into your router’s USB port for power and Ethernet. You can also attach an external hard-drive to it.

wget

$ sudo apt-get install wget

It is installed by default in Raspbian and lots of other Linux distros.

at

$ sudo apt-get install at

at allows you to schedule a command at certain time.

Let’s say we have to download Qt for Android 5.3.1 (Linux)

$ ssh pi@192.168.1.x
$ echo 'wget -c http://download.qt-project.org/official_releases/qt/5.3/5.3.1/qt-opensource-linux-x64-android-5.3.1.run' | at 02:00

The -c argument tells wget that if an existing download was in place, resume it 😉