[cessnadriver]

Jhogan0101. Had the same problem. Thought it was my Voltage Regulator, so changed one to a ACU (alternator Control Unit). NOT.
Comes down to adding a 8 gauge wire from rear starter to front starter then to battery ground. I know this sounds strange but I was told, by Dr. Dave, electrical engineer, that the resistance in the airframe, from loose joints and corrosion, needs the extra ground wire and believe it or not that works. Now alternators are producing the correct voltage to the buss which allow for the heavier load of the landing lights. One other thing you might need to do is adjust the voltage regulator output voltage from (Book number) 27.7 volts to 28.7. As Dr. Dave explains it the new battery manufacturers are requiring higher voltages for charging their batteries. Hope this helps.
Regards, BILLS