JZK 2 in 1 car truck bus voltmeter & thermometer display, 12v 24v battery voltage temperature meter monitor tester gauge indicator

Quick service. Good value. Very useful for monitoring battery voltage while running and parked

Smart little device - have one in each of my vehicles. Particularly useful for checking alternator and battery charge. Both accuracy of voltage and temperature seem OK.

Good product did job always

Bought this to monitor car battery that I thought was causing a problem with auxiliary electrics. Showed up problem, bought new battery problem fixed. Added bonus tells you temp in cabin and seems very consistent.

Product fits well into 12v socket, easy to use from inside the car with no need to go under the bonnet, appears to be accurate for both battery voltage and cabin temperature readings. Well built & good value for money at under £10.

Couldn’t be easier to use. Stick it in your redundant cigarette lighter socket, and it will give you a nice bright measure of your battery charge. The temperature reading is not that useful – other than to enhance your anecdotes of how staggeringly cold it was as you set off to work – but does no harm.I don’t know whether it’s accurate. It mostly gives readings on my car well below 12 volts. It might be an inaccuracy in the product, or because the voltage has fallen by the time it reaches the lighter socket. But it doesn’t matter. The important thing is that I get advance warning that the battery needs to be charged, rather than discovering in the darkness at 6:00 a.m. - when I should be heading to work - that the car has died.

This is a very accurate piece of equipment if you want to know what your car battery is doing. whether it is a good car battery or it's on it's way out. No need to go under the bonnet to connect anything to the battery just plug into a universal cigarette lighter and it will tell you what the battery is doing instantly whether it is holding its charge or even if the alternator is putting charge into the battery correctly. Should be around 12.5 to 13.5 volts for a good battery.It also has inside cabin thermometer witch is a nice touch aswell. Very good value for money and what it does and what it could do for you in future. Buy with confidence.

This is very useful to check battery health (reading with engine off), and also seeing if the battery is being charged when the engine is running. Engine off, you are seeing the voltage supplied from the battery. Should generally be around 12.5v for a healthy battery. When the engine is running, with a healthy charge coming from the alternator, you should be seeing around 13.5-14.5v. The display is bright and clear and easy to read.The temp reading is vaguely interesting, but I found that after being plugged in for some time on a longer journey, the unit gets quite warm, and so the temp reading from the little sensor which is on a small wire only about 3cm long gets a bit skewed by this and reads rather high. Once the car had warmed up, this was showing around 20c, which is about right. But after an hour it was reading 26c, which is definitely not (temp controlled car heating, it was no hotter).