Several banks in Heidelberg have branches around Bismarckplatz. Some of the banks cooperate, so it’s worth checking the ATMs from which you can withdraw your money without bank fees. (for example, there is the Cashgroup cooperation with Commerzbank, Postbank and Deutsche Bank)
Don’t pay for an account! All banks offer free student accounts.
We recommend Sparkasse, because you can close an account within a day, whereas it might take much longer at other banks. .The time it takes to close a bank account will matter if you wish to have your deposit paid back in in cash, since you need to have a closed bank account for that. In addition, Sparkasse has more than one ATM in the city.
In Germany, many places don’t accept cards - always bring some cash! EC cards (Maestro) are more commonly accepted than credit cards. Where cards are accepted, there is usually a minimum amount (10 or 15 EUR).