That depends on what glow charger you have. I bought one and charged it up and took it out for the first day of flying, used it all day. Then a day later, I went out again and did not charge the glow driver during the night because I figured it would last a long time. It died after a couple of starts of the engine and I had to borrow for the rest of the day. I plug my glow charger in after every time I go flying.