Blue Diamond's smart key battery called it a day yesterday by sounding continuous alarm after I unlocked, entered the cabin and started the engine. When I pressed the lock and unlock buttons, the alarm stopped and everything was normal. This happened for the second time in the last two months. First time, I attributed this alarm to the then drained 12V battery. When it is repeated for the second time - when the 12V battery is fully charged - I knew it's time for replacement of the smart key battery. Drove about 5 km in the neighbourhood before returning home. Everything worked alright. Today, when I checked the smart key by pressing the unlock button, the key fob LED indicator flashed a few times, indicating weak battery. So, replaced the smart key battery, costing ₹ 150 after 26 months from the date of purchase of Blue Diamond. Now, the smart key works fine with its LED indicator flashing once, when any one of its buttons is pressed. The wearable wrist band's battery was replaced earlier after one year. Now, it is also working fine.