Overcharging an AGM at 14.4 volts is almost impossible with a generator. Almost. Well a person -could- do it with a couple of 55 gallon drums as a fuel tank. Rigs that use Ford 2G, 3G, 4G and 6G voltage regulators spend their whole life charging AGM batteries at 14+ volts, for long journeys, day after day after day. Diesel pusher rigs with Leece Neville or Load Handler Motorola alternators do the same thing. Chevrolet and GMC with CS130, CS130D, and CS 144 alternators -- ditto.
Mustn't confuse ideal with mandatory. Pit nicking.
Timewise spending day after year on a power pole is differen't. There strict voltage control must be observed and there, is where 99.9% of overcharge failures occur, not from generator recharges.
Overcharging is a lot like radiation poisoning. The poor Hero of the Soviet Union who sat at the hole on the roof of reactor number 4 at Chernobyl played the part of a battery seeing a 17 volt charge rate, while directing helicopters of concrete to be dumped. He did not last long. But long strings of "volunteers" given a shovel and ten seconds to rush out on the roof and toss one shovel of exploded core over the side are still around. Get the point?
