hello everyone would need the scheme of a regulator, overload protector or whatever his name is. I tell you I have a source with a heat sink that is (12a13.7v 27amp) and I want to make a battery charger with it, it charges very well in case the only thing I would need is a voltage regulator and if possible something to give how many amp load

The voltage and the current are closely related and if you want to control the current, you must vary the voltage and vice versa, I don't know anything different. If you want to decrease the charging current of a battery you must lower the charger voltage and if you want to increase it you must raise it. That's what a charger or battery charge controller is all about. If the batteries are lead, you should charge them until they reach 14.2V and the charging rate (ampere) will depend on the type of lead acid battery and the manufacturer's recommendations. A charging regime of 10% of its capacity will ensure that in 12 hours the battery is charged. Greetings. Ric.