Copied from the Manufacturer's Spec Sheet..........


To achieve ICE's absolute maximum output power capabilities the
DC power source must be capable of delivering at least 15A while
maintaining 12V DC (although 12.5A is enough for most functions).

Perhaps he'd like to charge something at 7-8 amps or use the many other functions of the ICE that require a little more juice.

Can you run an ICE on 5amps.....yes.
Would I.......no.