I bought my CT200H in 2012 and it is now 2021. After 9 years, my battery has died. Through its lifetime the dome light inside was left on on separate instances over its 9 years and the car needed a jumpstart, total 3 times. The last time was the one that seemed to kill the battery last night. After jump starting the car, it seemed to run fine and i could drive on the highways. the next day, the car wouldn't start, the battery seemed to die again. Battery replacements estimate 4800$ now (inflation maybe?). In any case, battery replacement is definately a real thing to consider when buying these hybrids. I suppose Lexus and Toyota perfectly timed their warranty for batteries at 8 years as they knew that was near the lifespan of them anyways...Batteries on Toyota hybrids last the life of the vehicle. Period. They last longer then conventional transmissions and engine. The reason for this is the small change in battery state-of-charge as the hybrid is operating. You can call that change in SOC or delta SOC. By making the delta SOC small, the energy that goes in and out of the battery is small and therefore makes the life of the battery nice and long.
Lexus and Toyota warranty their hybrid batteries for 8 years of 160,000km. But battery replacements on Toyota hybrids is very very very uncommon.
The cost to replace the battery is approx $2500-$3000. Like an engine or transmission. But again. As I've mentioned. These batteries simply don't fail.
The main reason why people think these batteries would have to be replaced is because of their day-to-day familiarity with batteries of only one kind: those in small electrical items like cell phones, remote controllers, radio controlled toys etc. And with that day-to-day experience and familiarity comes the notion that batteries fail and need to be replaced.
That's not the case with these hybrid batteries.
Your second concern. The CT200h uses regular fuel. If you are DRIVING "green" in the summer/spring months you should be able to get 4.7L/100km. From the "empty light" (which leaves about 10-12L of fuel remaining in the tank) you can fill up 33-36L of fuel and that will net you about 680-720km of driving in the spring/summer/fall.
As with ALL cars, as soon as you get below 5 degC or even 0degC or -10degC, the fuel consumption is higher and sits around 5.8-6.0L/100km and nets you about 550km.