Actually A.G, a voltage regulator makes a pretty good lead acid battery charger I have made quite a few of them over the years.
An LM317 can be used as a voltage regulator, and will limit the current at about 1.8A by its internal current limit. Charging SLA batteries it won't stay long (if at all) in current limited mode, it's only a small part of the Charge cycle.
You can also use a resistor before the LM317 voltage regulator, which will limit peak current into the battery.
So Demis could use a common LM317 as a battery charger depending on some things we need to know like battery size and the power supply type and voltage etc.