12V Power Distribution

Clockwise from the top: ID-5100A transceiver, Super Booster voltage regulator, small fuse block, APO3, quick release data connectors, ground connection, 120A relay, large fuse block.

I replaced my factory battery with a Group 48/H6  X2Power AGM dual-purpose battery by Northstar (search for a similar battery cover to mine here). I ran 12V from the battery, through a 100-amp circuit breaker, and to the back of the car via Stinger 4-gauge amplifier installation kit to a 200-amp relay on the driver’s side of the subwoofer panel. The relay is triggered by a voltage controlled switch, the APO3. The APO3 allows battery power to feed the rest of the panel so long as its voltage is above 12.7V, basically any time the car is running, or for about thirty minutes after shutdown. Once the battery voltage falls below a preset threshold (I can set it for 13.05, 12.7, 12.1, or 11.8 volts) for a preset time (0, 5, 10, or 20 minutes), the 200A relay loses its trigger until the car is restarted and has run for a few seconds. The APO3 assures good battery health and no surprises as a result of a dead battery (been there, done that). From the relay, 12V travels to a Stinger fuse block. The large fuse block feeds the subwoofer amplifier, an LC2i audio signal converter, and an “N8XJK Super Booster” voltage regulator.

The Super Booster maintains a constant output of 13.5 volts (my setting), regardless of what the car’s battery is outputting. The Super Booster’s output feeds a Blue Sea Systems fuse block that supplies regulated 12V to the Icom ID-5100A VHF/UHF digital amateur radio transceiver, the Yaesu FT-857D HF/VHF/UHF all-mode transceiver, and turn-on circuits for the LC2i and subwoofer amplifier. There’s also a feed from the large fuse block that sends 12V back to front of the car via 70-amp circuit breaker to power my trailer lighting and a 400-watt pure sine wave voltage inverter.

All components’ ground leads are tied at a KnuKonceptz Bassik ground block, which combines all wires to a single 4-gauge wire. The 4-gauge wire leaves the panel and is fastened at a seatbelt anchor point that’s under the rear seat, just inches from the electronics panel. Some electronics parts manuals call for individual ground wires to be run all the way to the negative terminal of the car’s battery; and some argue against using a car’s body for grounding electronics components. The choices can be confusing! All I know is the negative terminal of my battery is immediately fastened to a stud that’s welded to the car’s body. See a photo below. Electrically, this seat belt anchor is the same point, with nothing but uninterrupted steel between here and the negative battery terminal’s grounding point.

This 12-volt wiring system is overkill for my application, but it should never be the weak link in my setup. Read more about the subwoofer system and the ham radio system. See a video about this distribution system here.

More Complex Than Required,