Charging a lead-acid batteries is rather complex matter.
First, the safety:
Even a discharged car battery can output enough current to melt your wires and/or start a fire and/or burn your hands, if you make a small mistake and short the battery.
An over-charged, over-discharged or simply damaged battery may produce hydrogen. It is explosive when reaches enough concentration in the air. Closed spaces are not good unless you really know what you are doing. Experiment in open air or at least near open window.
Wear goggles or safety goggles. The battery acid is not immediately dangerous, unless it gets in eyes.
The 'net is full of safety tips regarding lead-acid batteries.
Then, the charging device.
You absolutely need to use a power supply that limits both the current and the voltage. Not all SMPS devices behave adequately when overloaded. A discharged car battery can easily sink ~200 amperes if the charger has enough power and tries to "up" the voltage to 14v. The SMPS may either decrease its output unless the current drops to a pre-defined limit, or completely turn off, or get damaged. Only the first variant is good for charging a battery.
Set the SMPS to limit the voltage to 13.8 - 14.4v and the current to less than 1/10 of the battery capacity. A 60Ah battery needs to be charged with 6A or less. The wires should be adequate for this current.
Watch happily as the voltage increases up to the set point (constant-current phase) and then current decreases (constant-voltage phase). That's what the CCCV abbreviation stands for.
You can consider the battery 100% charged when the current drops below ~1/50 of the battery capacity (say, 1.2 ampere for a 60Ah battery). A higher voltage setpoint will shorten the proccess, but is worse for the battery life.
Observe constantly the battery temperature. If the battery gets ~50C, disconnect the charger and let the battery cool down. You may as well try with lower current and voltage limits.
A damaged battery may as well not reach the voltage setpoint. You should give up charging if the battery gets ~120% of its nominal capacity (say, 12 hours x 6 ampere for a 60Ah battery) even if the voltage setpoing is not reached.
You may as well stop the process at some intermediate point. A battery charged to ~10% of its nominal capacity should start the car with no issues. Running the car for an hour or two should get the battery to adequate state of charge.
Well, good luck.
Or just buy a charger. It does most of these things by itself.