Changed battery, check charging system light stays on

Old battery started car but drained easily when not running, ie; interior light left on for five minutes would then require jump start. Installed new battery and car starts and all functions perform but , "check charging system" light stays on where it did not prior to installing new battery. The negative cable casing, about an one and a half inches, had worn away (I think because of vibration due to its location) I cleaned the exposed corrosion that was visible and used electrical tape to mend. Everything else seemed in good condition. Ran the car for an hour and also turned on A/C, all systems worked fine. Each time I start car that CCS lights.