Have your Golbat in your party at all times.
Have it hold a Soothe Bell.
Level it up.
Give it stat boosting items (i.e. Carbos, Protein)
Walk around a lot
Don't let it faint or deposit it in the PC
when it has enough happiness, level it up and it will evolve into a Crobat.
(these methods work for all Pokemon.)
you have to give it maxed out happiness
You can but, you also need to give it Happiness or Friendship.
Golbat evolve into crobat with happiness
In order to evolve Golbat to Crobat, Golbat requires lots of Happiness. The exact number of your Golbat's Happiness will never be known by an in-game function however ways to increase a Pokémon's Happiness is to constantly let it battle and never let it faint and you can also give it vitamins such as Iron, Carbos and Protein. Additionally you can attach the Soothe Bell to it.
Golbat evolves with happiness.
Level it up with max happiness. You can give it a soothe bell, and train it.
Golbat evolves into Crobat when it levels up with enough happiness.
raise it happiness
Golbat doesn't evolve in pokemon red, blue or yellow. Generation II, and onward, if Golbat's happiness is high enough it will evolve into Crobat.
Golbat can evolve in any level. Golbat evolves into Crobat via happiness. Your Golbat must be happy enough until it will evolve. It can evolve from having fun with battles. I suggest you give it a Soothe Bell to make this proggress much quicker.
On full Happiness. :)
You have to evolve Crobat from Golbat since Crobat isn't in the wild.This is DEITY LINK not the other guy you evolve golbat into crobat by trading with Anyone it doesn't matter who or what they give you or what level it is its like gengar