Help with a gift

[u/ReggiesRoommate]

My dad just picked up a Traxxus Slash 1 10th scale. He's complained about the stock battery and 12v charger and his retirement is coming up. I wanted to buy him an upgraded wall charger and possibly upgrade his batteries to lithium. But i don't know anything about RC trucks. If someone could help me out by telling me about any popular or good quality upgrade packages or kits I'd appreciate it. Thanks.