| Δ0 | cigarette-lighter USB car chargers themselves | cigarette-lighter USB car chargers |
| Δ1 | other devices plugged directly into the car's 12V lighter socket | 12V phone chargers, dash cams, tire inflators, handheld car vacuums, 12V coffee makers |
| Δ2 | other powered car accessories drawing from the car's electrical system | GPS units, radar detectors, heated seat cushions, plug-in air fresheners, dashboard phone mounts with lights |
| Δ3 | built-in car electronics unrelated to the lighter socket | car stereo systems, power windows, dashboard warning lights, airbag control units, power door locks |
| Δ4 | portable electronic chargers used outside of cars | wall USB chargers, laptop power adapters, portable power banks, wireless charging pads |
| Δ5 | everyday household objects unrelated to charging or electronics | kitchen blenders, garden hoses, wooden chairs, cotton towels, ceramic mugs |