talkmagic.co.uk

if I have a hard drive to usb controller with a 12v 2amp input would I need a regulator to connect it to a 12v 20a/hour battery.

You are fine connecting it without any regulators. The 20a/hour bit refers to the maximum load per hour before discharging the battery. It's 12v and will run your drive for a long time based on the output capability.

David

many thanxs.