controller question

hi I have a a crystalyte 72v 60 ah controller that I want to use in the future, am I right in thinking that I have to use a battery with a max volt of 72 volts and total amps of up to 60 ah the cut out bottem limit is 55 volt on the controller.

Nope. A and AH are not the same thing. I can only assume you have a 72V 60A max controller with an LVC of 55V. Typical lvc for 72V controller is 60-62V. That's for 72v lead battery pack. 55V lvc is closer to a 60V lead pack, 16s 59.2V lipo pack, and 22s 70V lifepo4 pack.