LA Batteries are not self regulating. What makes it appear that they are is charging them with a voltage regulated (or at least voltage-regulated) charging source. If you dont believe me, try charging a six cell LA Battery with a power supply set to 20V open circuit...
If you use too much voltage to charge a battery that will boil the acid. A 16 or 17 or 18 volts good filtered DC power supply with amp meter is all you need. I have a battery charger that I built many years ago output is 16 volts with a selector switch for 17 and 18 volts DC. The transformer is 100 amp output. The amp meter shows battery will not take more amps than it needs. I can charge a small motor cycle battery, lawn mower battery, or any size car battery even a deep cycle 2000 amp boat battery on 100a 16v. A dead battery might pull 40 amps at first, the meter slowly drops as the battery charges, when the batteries is almost fully charged meter shows .1 amp. Changing the voltage from 16 to 17 speeds up charge time and 18 volts is faster. If you put a small 10 amp battery charger on a large battery that tries to pull 30 amps it will over load the charger if it does not have current limiting. If you put a larger 100 amp charger on the same battery it only pulls 30 amps even though 100 amps is available. The 100 amp charger is good to get a car started with a dead battery then let the alternator charge the battery.
I worked at Interstate Battery company in KY 1995 they had a continuous battery plate casting machine, injection molding machines to make battery boxes of all sizes, battery post casting machines, assembly lines built batteries then they all went to ware houses where they were all computer charged over a period of time 1 week or longer. Batteries were all charge as some pre determined rate that was best for that battery to condition the lead plates. A computer changed the voltage and changed the current all the time for a week. Voltage and amps were up and down all the time, sometimes 18v at 50a, 16v at 5a, 16v at 1a, 17v at 20a, etc. They learned from experience by charging a battery at all these different charge rates for a week it created a better long lasting battery. I was told to let an existing battery charge at its own rate with a 16v at 100a charger.