8-10 years is the life of the battery in Japan not Pakistan. They maintain their cars unlike Pakistani jo taxi ki tarah chalatay hain aur satia naas kar detay hain gaarion ka. No one here wants to buy a used hybrid jiski reason wohi hai complex systems hotay hain and if not maintained properly bohat maslay aatay hain.
Apki gaari tou waisay hai rarely used type hai. 3 years mein 35k driven only. Yahan logo ko dekhain 3 saal mein 1 lac km aram se chala letay hain. Phir dekhain battery kitna arsa nikalti hai.
As for the changing the sensor yes they designed it and they know better than us but again they themselves positioned them differently in models after 2015 for better cooling
and lastly i never said it worked better at low temperatures.
And your statement of greater efficiency at higher temperatures is incorrect.

Aik reference picture hai take a look at it.
I am not saying freezer se nikli hui battery sabse best perform karay gi there is a thing called optimal temperature not too low not too high
Japan mein bhi garmi hoti hai aisi baat nai hai k wahan garmi na hoti ho lekin wahan kuch areas mein zaida garmi hoti hogi Pakistan mein har jagga hi extreme garmi hai is liye batteries get more hot frequently hence people complaining k saal do saal mein battery change krani par gayi and due to the fact they dont clean the fan regularly is liye slightly the temp sensors on the battery helps keeping it within range of optimal temperature