Originally Posted by 92Roadster
...is that true for dashboard gauges that indicate higher
than 16, I have seen on my gauge from time to time but
have not had a problem with it.....
Vette gauges tend to read high & are not an indicator of actual readings. Like your car my volt meter reads high, I use it to insure the system is functioning not how well it is functioning.
Key on read the volts, start engine. If the volt reading is higher than the key on reading the system is charging.
You cannot test for a sulphated battery using the vehicle electrical system.
Test volts across the battery using an analog or digital volt meter. Engine off 12.4 - 12.6V = ok. Engine running @ 2000 rpm accessories off mid 14V range ok. If 15+ volts replace the regulator in the alternator. Continous overcharging (15V +) will kill a battery. Not instantly but gradually.