You must have one or more of the following: recover... 10,30,50,10,200,250,300.
now, put it in a folder. set any one of them as a regular chip (to do this: press select and select 'set a regular chip') go find any weak viruses. when your in the custom screen select the recover chip you set as a regular chip and when its battle time, use it and try to dodge all attacks until the custom bar is fully charged then run! to do an easy run; hold B while you're running. repeat the process until you have full life!