Your Audi charges fine in public but won't charge at home: what's really going on

This is one of the more confusing Audi charging complaints, because on paper it doesn't make sense. The car clearly works (it took 50 kW at the motorway services this morning), and the home wallbox clearly works (it charged fine last week, or your neighbour's EV charges from it). Yet today the session won't start, or it starts and drops out within seconds.

The good news: it's almost never the car. The bad news: "home charging" involves more variables than public charging does, and any one of them can break the handshake.

Why home is fussier than public

A DC fast charger is engineered to a tight spec and runs on a dedicated, well-grounded supply. A typical home setup involves your installer's wiring, your consumer unit, an RCD, the wallbox itself, its firmware, the Type 2 cable, and your house earth. Audi BEVs, especially the Q4 e-tron and other MEB models, are notably sensitive to earth quality. If your installation has a marginal earth (high impedance, intermittent neutral, or a PEN fault in a TN-C-S supply that the wallbox's open-PEN protection occasionally rejects), the car may refuse to start charging while the same car charges fine on a different supply.

This is exactly the pattern: public stations work, home doesn't.

Step 1: simplify the session

Before touching anything electrical, eliminate software variables in the car.

• In myAudi, remove any home location rules, departure timers, and "preferred charging location" settings.
• In the car, set charge limit to 100% just for the test.
• On the wallbox, switch to "free charge" or unauthenticated mode if available.
• Try a plain plug-in with no app involvement.

If charging then starts and completes, you had a software/configuration conflict, not a hardware fault.

Step 2: test the cable, then the wallbox

If the simplified session still won't start:

1. Swap the AC cable for another known-good Type 2 cable. A tired cable is one of the most common causes of "starts then stops" at home, because the control pilot signal is more sensitive than people realise.
2. If you have a portable charger or another wallbox you can borrow, try that instead.
3. If the car charges from a different supply but not yours, you've narrowed it to the home installation.

Step 3: check the installation, especially earthing

This is the step most owners skip, and it's the one that solves the stubborn cases. Ask your installer to verify:

• Earth loop impedance at the wallbox.
• That open-PEN protection (in PME/TN-C-S supplies) is not tripping intermittently.
• That the RCD type matches the wallbox requirement (Type A with built-in DC fault detection, or Type B).
• Firmware version on the wallbox itself, which often has charging-stability fixes in the changelog.

Cable check

Because AC cables are cheap to test and replace, it's worth ruling them out first. A Voldt® Audi-compatible Type 2 charging cable is a straightforward way to confirm the original cable isn't the problem.

Bottom line

If public charging works but home doesn't, the fault is almost always in the home setup: a configuration conflict, a worn cable, or, most often on MEB-platform Audis, an earthing issue at the wallbox supply.