Alone on the port, it keeps its promise
Used with a single device plugged in, the Anker 30W backs up a promise that is rare for this type of accessory: an independent measurement, carried out across five different voltage profiles, puts it at 29.3 W at 13.8 V and 29.7 W at 24 V, or 98% of the advertised power. The measured PPS window spans 3.3 to 11 V for around 29.7 W, enough for Samsung fast charging up to 25 W, but not for the 45 W an Ultra model needs, which requires a higher voltage.
A ninety-minute drive in traffic, phone plugged in under heavy GPS use, took a battery from 42 to 76%, a 34-point gain in 90 minutes for a single device charging. On this one port, the marketing claim holds up in practice.
With two devices, the split gets complicated
Where single-port use is convincing, two-device use exposes the product's real limit. An independent measurement confirms that total power stays capped at 30 W shared between the two ports, split at around 20 W for USB-C and 10 W for USB-A, rather than the 30 W plus 22.5 W that would add up if the ports worked fully independently.
This reduced split is not the only issue, though. Three separate, independently timed data points go further than a simple power split: they point to full cutoffs or repeated reconnections as soon as a second device is plugged in, including across several different cables tested to rule out a cable fault. One of these cases shows a disconnect-and-reconnect cycle every seven to ten seconds during a road trip with several passengers. This cutoff behavior goes beyond a simple power split: it suggests a charging renegotiation that fails on certain device or cable combinations, rather than a stable, predictable ceiling.
Heat that depends heavily on sun exposure
Under continuous charging at a moderate ambient temperature around 82 °F (28 °C), the housing reaches about 117 °F (47 °C) at its hottest, a reasonable figure for this type of product. Exposed to direct sun on a dashboard, the temperature climbs noticeably higher, to around 142 °F (61 °C), with thermal protection pulling available power down from around 30 to 22 W. This behavior is expected and, in a way, reassuring (the product protects itself instead of risking overheating), but it explains why the power actually available can vary widely depending on where the charger sits in the cabin.
Another limit worth knowing: the charger disconnects below 11.8 V DC, a threshold that can be reached at engine start or at low idle on a tired battery.
A format that remains among the most unobtrusive
At 0.53 oz (15 g) for 2.15 x 0.94 x 0.95 in (54.6 x 23.9 x 24.1 mm), the Anker 30W remains one of the most compact cigarette-lighter chargers on the market, barely protruding from the socket in most cases. Once inserted, it still sticks out by about 1.2 in (30 mm), enough to clear the gear shifter on most vehicles checked (2018 Toyota Corolla, 2020 Hyundai Elantra), even though the exact socket position can shift that impression from one vehicle to another.
Reliability: a minority pattern worth knowing
Beyond dual-charging behavior, extended use over close to a year shows charging power falling under 2 W in one case, checked across several cables to rule out a cable fault, a degradation signal worth taking seriously even though it does not represent the majority of the material available. One warranty case also involved a long wait before replacement, with the unit needing to be mailed back rather than swapped on the spot.
Versus the Ugreen 130W: two opposite philosophies
Compared with the Ugreen 130W, also reviewed on this site, the Anker 30W plays a completely opposite hand: simplicity and extreme compactness against three-port versatility and a 100 W peak. Where the Ugreen 130W struggles to hold its advertised power over time, the Anker 30W holds up very well in single-port use, at the cost of a much more modest total output and less predictable behavior once two devices share the charger. The choice mainly comes down to actual need: a single phone to charge quickly favors the Anker, several devices with potentially a laptop favor the Ugreen, with its own reservations about sustained power.
Who is this charger for?
The Anker 30W suits, above all, anyone wanting a discreet charger for one phone at a time, with power that genuinely matches the claim and a format that all but disappears in the cabin. For regular use by two people charging at once, better to factor in the reduced power and the occasional risk of a cutoff, or look at a multi-port charger built for that use from the start.
