After suffering a complete electrical failure The pilot of the single engine Piper PA-24 Comanche diverted to Rapid City, SD. Due to the loss of all electrics, he lost the use of his aircraft’s GPS, radio, and landing gear control. The pilot used his Ipad to direct him, in the night, the 80 miles to the nearest airfield with Emergency Services. The aircraft made an emergency belly landing on the small runway used for GA aircraft. Both pilot and passenger walked away with no injuries.