The Col USB official documentation claims one needs a minimum of 2 amps which is 10 watts. Now some people use up to 3.4 amps 17 watts which is the maximum offered when using 5 volt USB-C power supplies.
In theory a 10 watt 2 amp USB-C power supply/charger should power everything connected to the ColecoVision including Expansion module #1 Atari 2600 adapter and the Opcode Super Game module, however some people have went with a 12 watt 2.4amp USB-C power supply, 15 watt 3 amp USB-C power supply, or even a 17 watt 3.4 amp USB-C power supply since they had some issues not getting enough power to their ColecoVision. There might be certain variations of the ColecoVision hardware that might need more then 2amps when external hardware devices are used. Also USB chargers age just like other power supplies, and a 2 amp model that is more then 5-10+ years old might only be putting out 1.5 amps since its getting old. Also some off brand USB chargers put out less than the stated specs.
One of the reasons I spent a extra $10+ on a USB-C power supply and cable that offered 17 watt 3.4 amps of power, is because I knew I would have enough power to power about anything connected and also when power supplies age they give out less then the stated specs sometimes. So 10 years from now instead of getting up to 3.4 amps I might only get 2.4 amps or 2 amps out of the power supply. The Col USB plug is not going to draw anymore power then what the ColecoVision game system needs.
Edited by HDTV1080P, Mon Feb 18, 2019 1:20 PM.