FAQ
TL;DR: For Audi A4 B6, use 15A per socket; "I would give 15A for each." Add a separate fused line via fuse‑tap or battery feed. [Elektroda, Covul, post #17335964]
Why it matters: This helps Audi A4 B6 owners add extra 12V sockets safely for fridges, dashcams, and chargers without blown fuses or melted splitters.
Quick Facts
- Per-socket fuse target: 15A recommended for added 12V outlets. [Elektroda, Covul, post #17335964]
- Stock A4 B6 cigarette lighter is protected by a 15A fuse. [Elektroda, mjar755, post #17334499]
- Typical 12V cooler label: 46W cooling (~3.8A); 42W heating. [Elektroda, mjar755, post #17334528]
- Add power via a fuse-tap (Bypas Mini/Uni) or a fused battery feed. [Elektroda, Covul, post #17335213]
- 1.0 mm² lead OK for ~1 m at ~15A; 2.5 mm² taps exist. [Elektroda, Covul, post #17336027]
Can I piggyback off the existing socket or run a new line?
Run a separate, fused feed for each added socket. Use a fuse‑tap in the fuse box, or a fused lead from the battery clamp. That avoids overloading the factory lighter circuit and cheap splitters. “Make the second one on a separate line.” [Elektroda, Covul, post #17335213]
What fuse size should I use for an extra 12V socket?
Use 15A per socket. Treat any “30A” fuse‑tap label as a combined device rating. Protect each branch individually with its own fuse. “I would give 15A for each.” [Elektroda, Covul, post #17335964]
How do I add a second socket with a fuse-tap (bypass)?
- Fit a compatible fuse‑tap into a suitable slot in the fuse box.
- Install separate fuses for the original circuit and the new branch, matching the per‑socket rating.
- Route the positive to the new socket and ground the negative at a solid body point. Test under load. [Elektroda, Covul, post #17335964]
Where should I connect the ground (negative)?
Use a clean chassis ground. Crimp a ring terminal on the negative lead. Loosen a nearby factory screw, clean paint if needed, and refasten firmly. “You can try to find the mass on one of the screws.” Verify low resistance to battery negative. [Elektroda, Covul, post #17335964]
Is 1.0 mm² cable enough for the extra socket?
For about 15A over roughly 1 meter, 1.0 mm² was acceptable in the thread. If available, a 2.5 mm² fuse‑tap gives more headroom. Keep runs short and protected from abrasion and heat sources. [Elektroda, Covul, post #17336027]
Can I power a fridge, dashcam, and phone at once?
Yes, if the total current stays under the socket’s fuse rating. A dashcam plus phone charger is about 5A combined. Check your fridge label and add the currents. Use dedicated, fused sockets instead of a cheap multi‑way splitter. [Elektroda, DriverMSG, post #17334510]
How many amps does a 12V car fridge use?
Example label: 46W cooling and 42W heating. At 12V, that is about 3.8A in cooling mode. Size wire and fuses for continuous draw. Allow margin for startup surges and heat. [Elektroda, mjar755, post #17334528]
Why did my 3‑way splitter blow the fuse or heat up?
The fridge plus camera tripped the fuse, and the splitter’s branch end flared in the socket. Load and poor contacts cause heat in cheap splitters. Replace with dedicated, fused sockets on proper wiring. [Elektroda, mjar755, post #17334528]
Should I add a switch or make the new socket ignition‑switched?
You can add an inline switch before the socket. Easier: choose a fuse slot that is live only with the ignition. That keeps accessories off when parked and protects the battery. [Elektroda, Covul, post #17335964]
Is a direct battery connection better?
A fused feed from the battery clamp is robust. Many clamps accept an add‑on fused branch. Route the cable to the cabin, secure it, and mount your socket. “More fun, but probably more confident.” [Elektroda, Covul, post #17335213]
What socket hardware should I pick?
Use a quality, sealed 12/24V socket rated 15A for automotive use. Mount securely and protect the wiring. The thread considered a hermetic 15A unit for this upgrade. [Elektroda, mjar755, post #17334528]
Can I run two extra sockets from one 1.0 mm² bypass lead?
Keep each outlet on its own fused branch from the fuse‑tap or battery feed. Size each branch for 15A. “I would give 15A for each.” This avoids overloading a small single lead. [Elektroda, Covul, post #17335964]
Did this solution work on an Audi A4 B6?
Yes. The OP installed the second socket and reported success. “The whole hula as it should be.” The thread was then closed. [Elektroda, mjar755, post #17349577]
. You understand well, I looked at the sellers of the invention looking for load capacity, one wrote that up to 30A but it is possible that it is a value for both lines together, in total the fuses are also rather larger so I would give 15A for each and it should be ok for me I also have 15A per socket in the car. As for the switch, you can look for which of the fuses is only after switching on the ignition and plug in there. You can try to find the mass on one of the screws, put an eye on the cable, under the screw and hey banana.
