Wireless charging mounts are the most complained-about accessory in this category, and the complaints are consistent: it charges slowly, it charges intermittently, or the phone ends a journey with less charge than it started. The causes are predictable.
Cause one: the power supply, not the mount
This is the most common and the easiest to fix. A 15 W wireless pad needs meaningfully more than 15 W coming in, because inductive transfer is lossy — a good pad converts perhaps 70 to 80 per cent of input into charge.
Most mounts ship without a charger. Plugged into an old 5 W USB-A socket, a 15 W mount falls back to trickle charging, and every review blames the mount.
What the mount needs is a USB-C Power Delivery source of 20 to 30 W, and a cable rated to carry it. Check the mount’s stated input requirement; good manufacturers print it.
Cause two: heat
Inductive charging generates heat in the phone, and the phone protects its battery by throttling or stopping when it gets warm. In a car in summer this is not a marginal effect — it is the dominant one.
Two placement decisions matter more than the product:
- Out of direct sunlight. A phone on a sunlit windscreen mount is in the hottest place in the car. A low dashboard or vent position in shade is dramatically better.
- Out of the heater airflow. A vent mount is excellent in summer with cool air passing over the phone, and actively harmful in winter with the heater on full. Move the phone or redirect that vent.
Running navigation, music and a hotspot at the same time adds internal heat on top of everything else. That combination on a hot day is the classic case where the battery drains while charging.
Cause three: alignment and what is between the coils
Inductive efficiency falls sharply with misalignment, and the lost energy becomes heat rather than charge.
Magnetic mounts solve this mechanically, which is why they are now the default. The phone snaps into the correct position every time. But the magnets have to be present: a handset with a built-in ring works, a magnetic case works, and a thick non-magnetic case does not.
Clamp mounts grip wherever they happen to land, so a phone with an off-centre coil charges poorly and there is no feedback telling you why.
Also between the coils: thick cases, especially anything above about 3 mm, and anything metallic. A metal plate stuck on the back for an older magnetic mount will block charging entirely and can heat up.
What good looks like
- Qi2 or explicit MagSafe compatibility if you want reliable magnetic alignment.
- A stated input requirement, and a PD charger and cable that meet it.
- A mounting position out of the sun and out of the heater airflow.
- A short arm, for the vibration reasons that apply to every mount.
- Active cooling if you routinely run navigation on long summer drives. A small fan is noisier and genuinely works.
When to use a cable instead
- Short journeys where you want the fastest possible top-up.
- Hot days with navigation running.
- A thick rugged case.
- Any time the phone is already low and you need it charged on arrival.
A cable is more efficient, cooler and cheaper. Wireless wins on the one thing it was designed for — putting the phone down one-handed without looking — and that is a real benefit, provided the rest of the setup is not fighting it.
