Jebsens 4.8A 24W Dual USB Car Charger Volt Meter Car Battery Monitor with LED Voltage & Amps Display, for iPhone 7 / 6s / Plus, iPad Pro/Air 2 / Mini, Galaxy S7 / S6 / Edge/Plus, Note 5/4

The results of a geeky test are here. I like the unit, even though it does have a few kinks. I agree that color is pleasing in the evening, though it is a bit hard to read in the daytime. In order to determine its accuracy, I tested it with a power supply and several meters, as well as a Samsung phone and a Samsung tablet. It was a surprise to me at first that my vehicles reported voltage levels that high (old Toyota model At 3000 RPM, 5V or more is required). In cases where there is a huge voltage difference, the computer can switch between amps and voltages more rapidly. A modern car was not even available at 14 years of age. Four volts. Though I expected more in the range of 13, this is still within specification. The following is the result of the tests The first thing I did was to lower the voltage to see what would happen. An image of my test rig can be seen here. It is important to note that the supply wires were not large, and I noticed that some voltage dropped even at lower currents, such as It is important to note that I did not measure output current, but only input volts and current, but the output cannot exceed the input resistance. When the supply voltage is low, such as 10V, the unit will turn on, try to supply current, run out of supply, and shut off. Once more, it raises the voltage and tries to solve the problem. In any case, it is not a surprise. In eleven, there was no lunch. When the power supply voltage was raised to 7V, these effects evaporated, and the unit could supply a steady supply of 2V. The output current to my 2 devices is 73A (on the output side). In this case, your car would be off and the battery would be depleted, so a good result was achieved. *Some of the concerns mentioned that the voltage readings varied, and it did It is up to the USB devices (phone, etc) to control their Apparently, they are trying to draw a lot of amps, causing the output voltage to drop (guess, not measured), and then the load devices reduce their needs so that the output voltage can return to normal. After returning to their previous positions, the units do not get the perfect feedback they need, so they create more and more, and it repeats this cycle to a non-optimal state The voltage and amperage are not in a constant state, which is why you see some cycling. I would guess this is normal, but I would need to think about how the device would establish an optimum draw rate and try to maintain it. I was within 0 volts of what the display said it was, the voltage was exactly right. A voltage of 1V of true input voltage was measured at the terminals. However, it did vary by When the cycling was happening, there was a voltage spike of about 3V. On the input side, I imagine this would have been less severe if I had used larger wires. Currently, two units are being charged at the same time, with both screens on. The maximum input power is at 14VDC (0. The 95A code). According to the charger, there were three. At that setting, it would draw 63A on the output side. A power of 63 times five volts equals This is definitely not happening (it is impossible to output more power than it takes in). Therefore, the amp reading is accurate or the output was 3 instead of 5. In most cases, the charging voltage is only 7V as a result of the gate being wide open to the battery for a longer period of time (most likely), or the voltage is really 5V and the current is inflated. was not able to connect to either side of the battery, so I am not sure which is correct. The current readings seemed more reasonable at lower charge rates (within 10% of input power assuming 5V output). In my car, I ran the unit continuously for hours and noticed that it had barely heated up. This means that it could do its job very well. I don't know if the current is correct without more measurements, but it certainly followed the loads I gave it. USB charging can also be tricky with few standards, so without more measurements, it's hard to know whether the current is accurate. My Galaxy Tab S is too small to be charged properly by the charger, even with two huge cables. It will drop maybe 10% during a long journey in bright sun with a bright screen, no matter how big the cables are. In any case, it is not different from my Anker charger, which I also consider I would say at most as much as an Anker that's rated at 4 while the Anker is rated at 3. My tablet uses 8A total, so I suspect the charge circuitry on the tablet is just not up to the task of keeping the battery at 100% in bright sun with the screen on 100%, regardless of the charger used (the Anker and Jebsen have done the best I've There was no difference in that result when I added a phone, so it does not appear to be a power supply issue. I would rate this unit as good overall. We would like to hear from you if you have measured and compared.

Talon Floyd

| Aug 01, 2020

Besides being a voltage meter, this device also functions as a current (amp) meter (for usb charging) and a dual charging cable. With a large display, you are able to read it more easily than most. (If anything is charging) The display alternates between voltage, and amps to the usb port. By turning the ignition key to the "on" position but not starting the car, you can measure the battery voltage. When you start the car, you'll be able to see the voltage of the alternator. The device allows you to monitor the most critical aspects of your car's electrical system quickly and easily. While the blue LED display looks great and is easy to read in daylight, it is a little hard to read in bright light. Apparently the surface is glossy, so reflections of the sky through the window or objects in the car obscure the numbers. Assuming it isn't dim, the problem is that the surface is glossy. I wouldn't recommend that you do that while driving, but you can shade it with your hand. A sheet of instructions and specifications is included with the product. If you don't want the instructions, you can ignore them. I was able to use it right away. I use this in my lighter outlet because it sticks well. It hasn't been a problem for me to pop it There is certainly a difference between car models in that regard. run into difficulty, I suggest you add a little electrical tape (or any non flammable tape) to the part of the shaft that is plastic. Cover the metal contacts but not the plastic ones. It is important to know that this does NOT measure the overall current (amps) your car's battery is drawing. That would require a wire that is connected to the battery cable of your car. A USB current monitor allows you to monitor connected devices' current (amps).

Salvador Lynch

| Aug 03, 2020

Sister - There is always a problem with the battery in my wife's car and she is always worried about it dying. By turning the key on this little sucker, when she turns on her old car, she knows she has enough juice to start it. I would recommend this to anyone who would like peace of mind and to see her Batt as well. The battery gets really low (she doesn't drive far, so it doesn't get charged like it should) so she gives me a call BEFORE she runs out of juice and we put the charger on. I was going to give it 5 stars except that it's too small to fit in my pocket. This is because the display is located tightly against the plug, making it difficult to view. It would be much easier to view that display from the driver's seat if they would cock that display about 45%. The system works very well, however.

Alonso Wiley

| Jul 10, 2021

As an introduction to this product, I'd like to clear up my reasoning for buying it. I own a 1996 Chevrolet Tahoe and it is experiencing the following issues According to its charging gauge, the battery is low on charge. There is no problem with the battery voltage. I have checked it multiple times. In spite of this, the gauge on the instrument panel shows between 9 and 14 volts, or 11 volts if you do the math. The fifth version. In the end I decided to put it aside for a while. One night I was driving, it was hot, and the A/C was on, headlights were on, and the radio was playing, and I just noticed that the gauge needle pointed That scares me a bit. Based on what I calculated, the number is There are 13 digits in 5v. It's like 11something volts to convert 7 to 9. It was at 13 degrees when I went to a shop the next day to have my alternator checked. A stamp on the alternator states that it can produce 100 amps at maximum output if loaded by 7. It did not find any problems.

Now, since my gauge is starting to freak me out, I bought this unit to keep an eye on the battery/charging voltage. I was driving it with the battery gauge reading 9 and I looked at my cigarette lighter and it read Having a piece of mind is an incredible experience. Though I probably should have the gauge looked at, I'd prefer to take a look at it for less than 20 bucks than spend $200 or more on getting the gauge diagnosed.

Remy Shelton

| Jan 05, 2021