I will be traveling to Berlin in June. I would like to know if there is a travel card I can buy and use across all the public transport options (bus,tram etc) for a week. Ideally, it could be a pay per use card for which I could get the balance refunded when I return the card.
Edit(replying to the comment): I prefer travel cards over single ride tickets for saving time. I want to avoid queues. I also want to avoid cases when I am not allowed to ride since I don't have the exact change(happened to me in Singapore). I later came to know that Singapore has this exact type of travel card which I am asking for :-)