Battery Capacity Monitor, Icstation DC6V-30V Battery Voltmeter USB Fast Charger Car Battery Monitor Meter with LED Voltage & Amps Display for 12V 24V Lithium, Iron-Lithium,Acid-Lead Battery

The battery charger/monitor charged my iPhone 8 at 2 amps and 5 volts (10 watts) in about 40 mins - pretty decent. This is just about equivalent to Apple's 12 watt standard charger, and not much worse than Apple's 29 watt and 61 watt fast chargers. The fast chargers can charge an iPhone 8 from fully discharged to 50% in about 30 minutes. Note that the iPhone require a USB-C port and corresponding cable to support fast charging at the higher power levels. This unit has USB-A ports. All fast chargers will put out more power when the battery is nearly discharged. As the battery charges up or if the battery isn't fully discharged, the fast charger and the phone negotiate to allow less power to enter the phone's battery to protect it from overheating. Heat is a battery's worst enemy.I use this in my car to monitor my 12 volt car battery by using an adapter that plugs into the cigarette lighter. Because I haven't been using my car much these days, my battery has been discharging so the monitor is helpful. I have an older car that doesn't have a USB port so this comes in handy for use with my iPhone when using a navigation app.I haven't tested this on Android phones and other types that use different technologies from the iPhone - such as QuickCharge and USB-PD. Those devices may actually get a fast charge.

This little voltage meter is nice and simple to use, I planned on using this in a project and it fits my needs perfectlyWhen hooked up to a DC voltage of 12V it supplies a stable 5v output on both USB ports, USB supports Quick Charging devices. The display backlight can be toggled on or off. The display is fairly detailed with information such as input voltage and battery level, out put voltage and current consumption. This can be useful in a variety of scenarios like for hobby projects, installation in a car, or off roading vehicle. Id highly recommend it in use in a battery box or for a small solar charging setup. The only real complaint I have is the tabs on the side don’t provide a lot of grip and will need to be trimmed if panel mounting this device.

This little voltage meter can be mounted in your car or be used on your workstation if you're dealing with electronics . It can help monitor the life of your batteries so you can see the progress if its fully charged or not. You have the ability to select whatever battery lipo battery voltage you want and it'll provide all the information for you. The highest it can take is 30 volts, and the system will step that voltage down so it regulates the 5v on devices for usb charging without damaging it. It also displays the reading of what current DC load its taking as well so you'll know how much is going in there.

I wanted to note some differences and tips for other purchasers of this device. Another reviewer said that the backlight on this device automatically turns off after a few seconds. This is not the case with the unit I received. A short press of the button on the front of the unit turns the backlight on. The backlight stays on until the button is pressed again. Another great feature of this unit is that it remember the backlight state even after power is removed.Another reviewer mentioned that the battery capacity indicator is not accurate unless he sets the unit to the lowest number of cells. When setting the number of cells you want to set it to the number of cells in series. If you have cells in parallel don't factor that in to your count. Also ensure that you set the battery to the correct type.There are three battery type settings Fi3.7, Fe3.2, and Pb12v. Fi = Lithium, Fe = Lithium Iron Phosphate, or Pb for lead acid. For those connecting to a standard 12v car battery select Pb12v and 1S.Instructions:1. Apply power to unit2. Hold down button until battery type selection appears3. Short press button to toggle between battery types4. Hold down button until number of cell selection appears5. Short press button to select number of cells6. Hold down button until main screen appears againWhile on the main screen short press button to toggle backlight on and offQuick refresher on series versus parallelSeries = Batteries are connected + to - and output voltage increases as each additional battery is connected in series.Parallel = Batteries are connected + to + and - to - and output voltage does not increase as cells are addedAnother great feature of this device is that it shows the current draw on it's USB ports. Ever notice that your phone is charging slowly with that $2 cable you thought was a good deal? Use this device to see what cables allow your phone to charge at the highest rates.

This thing works well but only after 3 weeks, LCD screen starts going out. Gonna be useless without lcd screen.