Originally Posted by
drivesafe
Hi folks, and first off, other than for a very short period after starting, you should not be seeing 15+v with a Calcium/Calcium type starting battery.
In cold climate countries, during the winter months, you will see constant 15+v. We do not get that cold here, so again, constant 15+v is NOT GOOD for your cranking battery.
If you have an AGM starting battery, you should never see anything above 14.7v, even with a low battery.
Those with high operating voltages, can you try a hard reset and see if it lowers the “constant” operating voltage.
As for Optima Yellowtops, they can be fully charged with as little as 13.65v but will tolerate constant voltages up o 15.0v.
The Redtops and Bluetops can be charged with as little as 13.3v, up to 15.0v