Legion Y740, 4 to 5 hours battery life under use. After updating bios, enabling hybrid graphics mode, undervolting cpu by 155 mV and setting screen brightness to 50%. : r/Lenovo
Genuine 76Wh L17M4PG2 L17C4PG2 Battery for Lenovo Legion Y740-17 Y730-17 Series | eBay
Genuine 76Wh L17M4PG2 L17C4PG2 Battery for Lenovo Legion Y740-17 Y730-17 Series | eBay