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.