Anti-Japanese War: My Mobile Phone Can Only Hold 100 More Chapters

Traveling through 1938, I started with a mobile phone with 62% battery. System prompt: Zero battery = death. Number of remaining chapters - 100 chapters. Within 100 chapters, kill the Japanese, seize the city, and build a base. After Chapter 100, the phone battery is out of power, how can he survive? What's even more deadly is that he is not the only time traveler on this timeline.