Auto Battery Monitor BM2 Bluetooth 4.0 12V Device Car Battery Tester

It was very simple to install and had it up and running in no time at all. From time to opening the package to hooking it up & connecting it to the app on my phone, it took less than 5mins. The app associated with this device is very responsive and quick to connect. The bluetooth distance is quite good and I can sit in my house and it still recognizes the device even when I'm on the other side of my house. Very pleased with this. Highly recommended.

It does a good job of monitoring the battery when you are in proximity to the vehicle. The app is pretty good and easy to install and use. It helped me find out that my 1.5 year old AGM battery was marginal and should be replaced.

I’m going to give it 5/5, but it does seem to interfere with my Bluetooth audio signal. Not sure if this is due to the number of devices I have paired to my phone, the strength of the signal, or the amount of data being transferred. If I disconnect the Battery Monitor app, my audio works instantly.

I have an EV whose HV-battery has occasionally failed to maintain a full charge on the 12v battery, leaving me with a discharged 12-v battery. This tiny battery monitor and app were both really easy to install and allow me to check the state of my 12-v battery well before I start a trip, so I know whether I need to attach a battery tender or portable jump starter before starting. The only complaint I have is that even with Bluetooth 4.0, I have to get fairly close to the car and make sure there are no obstacles like walls when I want a battery reading. If somehow this tiny little beast could have a better range without sacrificing size, it would be absolutely perfect.

Works great. Good idea for monitoring your battery. I have 4 batteries that I monitor with these. I like the ability to know the status of them at time.

I have a charge controller and large battery bank for my solar. My charge controller lacks bluetooth features. It does display the current voltage, but I have to go to the unit to see it. Likewise, it doesn't have a way to transmit or store historical data.I bought the BM2 thinking it might be a quick fix for this, and I was pleasantly underestimating the device. I connected it to the leads of the battery, opened the app, and connected the device. There was no pairing issue, no hunting around for some long forgotten Chinese app. Everything was easy. The device was detected and linked instantly almost. It let me select my battery type, name the device, and it went to work. I saw the voltage readout on my phone, and it started charting the voltage. This was in the middle of a sunny charge cycle, and the voltage was consistently rising, updating every second on the app.As for accuracy, it matched the readout shown on my inverter precisely. I was so blown away by the speed, usability, and simplicity of the device and its app that I considered buying another for the car. If you have a battery for utility, camper, truck, solar, boat...you need this. It beats pulling out the multimeter, it is accurate, and the ability to chart the data is priceless. Given the insights the data will provide, I don't doubt this device will pay for itself within a year.

It is important to know this battery monitor will only communicate with a Bluetooth device -- like an iPhone -- over a very short distance. Maybe a dozen feet. And said iPhone needs to have its Bluetooth turned on, which is a small but continuous power drain.My Quicklynks unit is problematic. It tends to underestimate the charge on the battery, complaining that it is almost out of charge when it still has plenty of cranking power. Also, it sometimes says the battery is still being charged after I've turned off the engine.I'm learning to take its reporting with a big grain of salt. I still think it has some value, but I'd be happier if it was more accurate, and had more transmission range.Before I bought this unit I had purchased another, similar device that was supposed to link up with my WiFi network, and do much the same in terms of monitoring the battery. Unfortunately that device also suffered from poor range. It could not link up to my WiFi system while sitting in my driveway, just outside my house. That, plus a difficult setup procedure, led me to return that unit for a refund.If I can find a better battery monitor -- one I can trust, has WiFi capability and decent range -- I'll probably replace the Quicklynks unit. For now, I'll leave it installed.Update March 27, 2019 -- Unit is no longer working at all. It has been reading "0% Charge" on the battery, when there is still plenty of power to crank and start the vehicle. I can no longer return it through Amazon -- I'm past the 30 day limit -- so I am trying to get the vendor to replace or refund it under warranty. But their phone number listed on the Amazon product page has been disconnected. I haven't given up yet, but I'm probably going to have to go through Amazon to get the vendor -- Quicklynks -- to respond.Short version -- don't buy.

Easy to install and use. Had it a week. So far, so good. Ordered another one. Check your battery while you are having your coffee. No last-minute Suprise! Works at least 40 feet for me. Your results may vary! The history feature is nice. Could show a coming failure, or be useful to an Auto Tech when a problem develops.