Different batteries require different types of charging topologies. Li-Ion are the worst as these have very precise charging requirements. generally all batteries require a current source to charge them. With Li Ions, you look to see when the voltage reaches 4.1V or 4.2V (depending on the type of battery) then terminate the charging. This voltage has to be measured with a 100mV accuracy.
NiCads and NiMH are charged with a constant current until the voltage starts to dip, or the temperature starts to rise rapidly.
Lead Acid (car batteries) are charged with a voltage limited current source, then terminated with a current limited voltage source (1.25V per cell). (This is from memory, but I think itis correct).
You cannot mix and match chargers and batteries, especially with Li-Ion batteries as they tend to explode.
Laptop batteries also have intelligence in them (a micro of some sort) that include charge/discharge cycle counting, coulomb counting etc, so you might be doing irreversible damage to the battery (and yourself if it explodes) if you hook up any birds nest of circuitry to it to charge it
I am surprised you charged a car battery (12V) with a 5V source as the charging voltage always has to be higher than the final battery voltage