Electronics/Tea and Coffee vending machines.
Is it possible to design tea and coffee vending machines operated also on Batteries?.
Well, it is possible but not a very good idea because of the enormous amounts of electrical power necessary to heat a mug of liquid, be it water, tea or coffee. Since it is for heating a beverage you would want a fairly quick heating action so the customer would not have to wait in line a long time.
The amount of electrical energy to heat a full mug to the hot level within one minute, for example, would require around 3,000 watts of electrical source. The battery would be huge and would need to be recharged frequently. A 12volt battery would need to supply 250 amps of current. In order to run for one hour, for example, you would need a battery with a rating of 250 amp.hours. A 100 amp.hour battery would cost around USD$100 and you would need 2 or 3 of them for one hour of operation. If you wanted a full 8 hours of heating time then you would need 16 big batteries of one kind or another. Each battery would weigh around 20 lbs, depending on the type.
The idea of battery operated tea and coffee vending is not practical at all. Sorry.