Vivo is preparing to expand its Y-series lineup in India with another battery-focused smartphone.The Vivo Y31t 5G is now listed on Vivo India's official website, confirming the phone for the Indian market and revealing most of its key specifications ahead of wider availability. (Vivo)Its biggest attraction is easy to spot: a massive 7,200mAh BlueVolt battery packed into a phone that measures around 8.39mm thick.7,200mAh Battery With 44W ChargingBattery life is clearly one of Vivo's priorities.