Formula for determining Battery size needed
Does anyone know the formula for determining battery size needed for a watt / amp solution? for example I was running a 3000 5 S 40 C with a Hoffman magnetics EDF motor and a 150 amp ESC. The motor puffed my battery. A fella at the field asked me how many amps I was pulling and I told him 125 amps. He quickly did some math in his head and said I needed at least a 3300 battery. How did he figure that out? I didn't get a chance to ask him and haven't seen him since.