Keep in mind...
A battery manufacturer is going to insist on care and maintenance that makes the battery and them look "the best".
Charging time requirements, worn-out generators and long drives for gasoline are no object - optimum battery life is number one. Even if 10% added battery life costs 40% of the original cost of the battery.
Back float voltages down to the point where a fully charged battery does not lose or degrade the density of the OEM specific gravity of a fully charged new battery. This is trial and error. No 24 pin logic chip on the face of the earth can replicate this protocol.
Once a year watering? Mena, try not to imagine nits to pick too hard. Engineers have to say -something- or they eventually get a pink slip. "Hey there Roy, tell us why we are paying you 80K a year?"
Battery manufacturer's "instructions" should be regarded as tips and hints. Not gospel!
Armed with a voltmeter and a hydrometer an informed consumer can rip the shorts off any battery engineer whose guesses are far removed from the site of the battery itself. I wouldn't argue with BFL13, or Mena, for instance for all the tea in China. What they find is reality. It's foolish to try and outguess facts.