The old battery My iRova KK8 robot vacuum battery finally gave up after 12 months of almost daily use. Some times I would just setup the timer and leave it for few days when I go out of my home for holidays. At the 10th month, the iRova KK8 can only run for 30 mins compared to 90 mins when its brand new. By 12th month, it can only run 20 mins. So thats when I decided to get a new battery from iRova . It cost me RM180 and I think it's a reasonable price to pay. Since I am going to throw away the old battery, I might as well tear it down to see what it made of. Surprisingly I found a thermistor (temp sensor) that provide temp reading to the iRova robot when charging. Peeled out all the adhesive tape that covers the connections. This is a temperature controlled cut off circuit (i think) The whole battery is basically made of 12 AA batteries. References, Sources and Credits: http://www.i-rova.com/product-1199190.html
