Is 12.5 volts sufficient for battery maintenance?

gperky wrote:
I have 9 batteries. 5 are on Battery Tenders that maintain at 13.2 volts. 2 are on larger automatic chargers that maintain at 13.2 volts. The last 2 are on cheap Schumacher and Harbor Freight charger/tenders that maintain at 12.5 volts. Is 12.5 volts good enough to prevent sulfation and early demise of those batteries?