Also. Remember the old 2,5” external USB HDD y-style cables that had an extra USB 2 plug (connected with a thinner cable with just 2 wires for the power and not data) that you could plug into a second USB sockets so the disk draws power from 2 ports? Maybe such thing still exists for current USB disks.
You can then plug the second plug into a standard USB charger for smartphones or similar.
You can use a powered USB hub.
Also. Remember the old 2,5” external USB HDD y-style cables that had an extra USB 2 plug (connected with a thinner cable with just 2 wires for the power and not data) that you could plug into a second USB sockets so the disk draws power from 2 ports? Maybe such thing still exists for current USB disks.
You can then plug the second plug into a standard USB charger for smartphones or similar.