it doesn't measure correctly, one time it outputs 5 volts, the other time it outputs 12, it stops charging the phone and then starts again by itself

As a charger, it works like almost all of them in this price range. The voltmeter is not visible at all during the day and literally only in complete darkness if you focus on the readings. If you are particularly older, good night...

I got it to monitor the volts of my car battery, not as a charger. It does exactly what I wanted, I can monitor the battery volts "live" and continuously. I hope it will be useful when, after years, the 12V battery weakens, so I can catch it and replace it before it dies. Logically, if the battery weakens, I imagine it will stop showing 14+ volts as it does now, and will probably show 12 or 11.99. I suppose. As a charger, I haven't used it because I already have another one that came with the car, but it does have two regular (large) USB ports if someone wants it for that use (though it doesn't come with a cable).
As for the build quality, it seems sturdy, and it fit immediately into the adapter. Negative: its little screen that shows the volts with red LEDs is very small, and since I have presbyopia, it's hard for me to see it, but OK, I can see it.

Very good. Its connections are reliable. Small and flexible. It can be inserted and removed (if needed) easily and simply.

Sometimes it charges quickly and other times not... The battery voltage indicator does not light up... wasted 10 euros

Permanently connected due to the base that needs power, it has never complained or overheated even when 2 devices are connected at the same time

Powerful charger. It frequently disconnects and restarts the charging. Also, it doesn't fit perfectly in all lighter cases.

Although it obviously won't handle a high-performance mobile charger that is, I don't know, 50+ W, it does its job and charges perfectly, and instead of having a useless cigarette lighter, you can have this for just a tenner. Also, a nice bonus is that it tells you how many volts and amps it is drawing.

It shows the vehicle's voltage and when charging the phone alternately I see the vehicle voltage, phone charging voltage, and phone charging amperage

A minor downside of the Display for the Volts is that it is only visible in complete.....darkness! Otherwise, VFM.

Baseus, whatever it produces is a guarantee in functionality and quality. Once you plug it into the lighter socket, twist it a little until the red indicators light up to operate. As for charging, it's faster than the phone charger.

Reading the reviews about the low brightness of the voltage indicator, I thought they were exaggerating. It really is true; to see what it says, you need almost complete darkness. As for the charging, the fast charging works properly on the Samsung A52 without any issues.

Good construction, but the screen with the battery indicator is extremely weak, resulting in it being hard to read.

It does what it promises, but unfortunately, the brightness of the indicators is poor... they can only be read in the shade. With a supervooc charging cable, the OnePlus 11 only recognizes it as vooc charging... with other cables, the charging is similar or a bit slower... I assume it ranges between 15w-20w... Be careful if you are charging from both ports, we are no longer talking about fast charging

Purchased exclusively for measuring the car battery voltage.
Theoretically, while the engine is running, it should show a reading of ~13.5V, and while it is off ~12.0V.
It seems to work correctly and is recommended for this purpose.
It is worth mentioning that the digital display is of unacceptable brightness. In sunlight, I was unable to read it.

So far, it charges two devices normally. However, it has a little issue with the application in the car's socket. It doesn't fit well

Very good. It has the power it says. Very good application.

Nice that you can also see the battery level.

Excellent charger delivers 45 watts fast charging tested on Huawei P40 Lite and Redmi Note 10. Fits well in the car lighter. The measurement of the car battery is accurate. Measured with an external battery charger. I would like the numbers to be a little brighter. They are visible during the day but could be brighter.

Very good and it looks high quality, and mainly it has good contact with the car lighter (in the past, with other chargers they did not fit well and lost contact with the slightest movement).

I have had it for about a month. It works perfectly. The only problem is the cables, because whatever I have bought does not reach the Watts that this one provides, I have charged up to 18W. The screen is flashy and correct. Beautiful and functional gadget. It is worth every penny.

In order to achieve the 45Watt it claims, it needs to be connected to a 24Volt socket and not a 12Volt one. I haven't tested it on a 24Volt socket, but it is mentioned in the instructions inside the packaging.