Yes pressure can rise if you float at 15.0 volts Death Valley Junction.
Someone has passed a bowl of snot along as facts. When an AGM hits a brick wall fully charged it takes an enormous amount of wattage to cause them to gas.
"Caution should be exercised during deep recovery as voltage may rise as high as three volts per cell with constant CURRENT charging. Under certain circumstances battery venting may occur" -- Lifeline.
That is a few galaxies distant from a slightly high float voltage.
When those vents stay closed it is impossible to lose gasses. They are recombined.
Many emergency motor vehicles use Lifeline
Do they dry up and catch fire...........no
Do they insult the intelligence of fire, PD and ambulance shops? No.
Those batteries get hotter than the cast iron hinges of hell and still manage to render good service.
Ain't life grand? "Abused" motor vehicles Lifelines last longer than their cousins subjected to insane asylum grade management of an RV converter.
I keep harping this...
