On May 28, 2018, about 2015 central standard time, an experimental, amateur-built RV-8, N214FF, was substantially damaged when it was involved in an accident near Somerset, Wisconsin. The private pilot and passenger received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that, about 10 miles from the destination airport, the sky was dark, with lightning and increasing wind conditions, and he decided to divert to his private grass runway. Shortly thereafter, the airplane's radio and GPS unit started to flicker and then went completely dark, followed by a total loss of engine power. The pilot attempted to troubleshoot the loss of engine power and stated that the mixture was at full rich and the electric boost pump was on. He noticed that the switch light on the electric boost pump was very dim and there was no response when he flipped the switch. He tried to “pump” the throttle and changed the fuel selector from the left to right tank, but engine power was not restored. The pilot stated that he was losing airspeed and altitude, and he selected a field to conduct a forced landing, during which the airplane's right main landing gear impacted a fence, resulting in substantial damage to the wings. A Federal Aviation Administration (FAA) inspector examined the airplane after the accident and reported that the main battery was a homemade, gel-cell battery with a bundle of small, melted wires attached to the positive battery post. One of the wires in this melted bundle was connected to the engine's electronic ignition system. A backup battery was mounted to the engine firewall with a spade connector wire lead, which was disconnected. This wire connected the electronic ignition to the backup battery. The back-up battery was tested with a voltmeter and was fully charged.