I will add to the thread with regard to 3rd party battery called Ittou, which is available at OP. Continuous usage of taking photographs and some short videos last up to 3 hours and a total of 600++ photographs. My son used the K30 + DA18-135 for the Tokyo Auto Salon and by the time I took over at 4pm, he had used but both the original and the 3rd party battery.
Bringing the K30 to Bangkok recently, the batteries lasted longer and they lasted about 1.5 days each.
I have also bought the DiviPower brand that some of us used on the K5/K7 this afternoon. I am charging the 2 pieces I bought and will start to test them tomorrow.