I've got one of these on each of my trucks. It works great and allows me to see what is happening with the 12V battery while the truck is off.Today's vehicles have many modules and some don't shut off until a half hour after the ignition is switched off. Some manufacturers are installing 12v batteries that are too small for all of the conditions the vehicle may face - such as vehicles parked outside during very cold winter temps. If the 12v gets too low it can cause all sorts of warnings and problems in your car. Knowing your battery voltage over time is extremely helpful in diagnosing battery issues.

installed in about 5 minutes - bluetooth connected 1st time really easy and there it was the voltage of my leisure battery handy for when all the kids are using my battery to charge all there phones - it enables you to not damage the battery and run it too low - ok so it has a crank setting which i have no need for on a leisure battery but you can set it to notify you when battery gets low which for me after destroying two AGM batteries because we used to run them flat as i had no way of telling pre my solar kit is fantastic - good but of kit for not a lot of money. IF YOU HAVE A CAMPER THIS IS SOMETHING YOU NEED

Als Ford Fahrer habe ich das bekannte „12 Volt“ Problem und nachdem ich 2 mal morgens vor einem „Toten“ Auto stand musste etwas zur Batterie Überwachung her…Das Teil hier ist total simpel zu verbauen und erfüllt seinen Zweck zu 100%. Die App ist ebenfalls sehr einfach zu bedienen und hat diverse Funktionen zur Überwachung bzw. Testen der Batterie.

This is a well made unit that is quick and easy to fit and works well with the app.The only downside are the instructions but it's easy enough to figure out without them. Just make sure you download the correct app and it will work seamlessly.

Funciona bien hasta el momento ya tiene mas de un año conectado al automóvil.

I wasn't looking for this monitor when I happened upon it on Amazon. I work in the motorsports industry and had not seen anything like this in the dealerships and shops I visit on a regular basis. And since I'm an electronics geek who's also in the motorsports field I had to try this.Before I ordered however I checked out the Ancel Battery Monitor App in the iOS store. There were only 4 ratings at the time with three 5-star ratings and one 1-star rating, the app looked promising so I ignored the one negative rating and ordered up.Once in hand I found the ANCEL BM300 Battery Tester/Monitor unit to be smaller than expected, measuring 3 ¾" Wide x 2" Long and 7/8" Thick. (Tapered design, see the pic below with measurements). The two lead wires are roughly 7" long with open clips on the end.To install I just had to hook up the leads to the positive and negative ends of the battery on my motorcycle. I then went into the app and expected to have to fool around with Bluetooth connections but the monitor had already paired to my phone and was showing the current battery voltage. Sweet! (see pic)From that point I started the motorcycle and the ANCEL BM300 showed the current charging rate and battery voltage with the battery voltage showing on a line graph. (see pic) I then ran the Charging Test and the charging voltage at idle and high RPM was shown. (see pic)The ANCEL BM300 will also perform a Cranking Test which shows the cranking voltage as a numeral and also on a line graph. Note: I like that the app shows good readings in Green and low or bad readings in Red. The Ancel also has a Trip setting which gives you a history showing times and duration for the vehicle (car, motorcycle, etc.) has been running.The app also has some more features in the System Set-Up allowing set two separate Power alarms at a % of your choice. These alarms will remind you once the battery is below the chosen percentages, I have mine set up at 70% and 50%. You can also choose to have a Daily Power Notification or Abnormal Cranking Notification.So far I am very impressed with the functionality and ease of use of the ANCEL BM300. The Bluetooth range is strong enough that I can check the battery status on my motorcycle from my living room with it being 30 feet away inside a garage with concrete block walls.The only negative I can think of is that as far as I can tell the Ancel Battery Monitor App can only work with one monitor at a time. If it worked with more than one vehicle I would buy one for my truck and my camper as well. I would also have an extra monitor to use for diagnosing battery/charging issues on the motorcycles and off-road vehicles I encounter for work.