BM2 Bluetooth Battery Monitor 12V Car Battery Tester for Lead Acid, Auto Battery Load Tester with Cranking Charging Test, LowVolt Alarm for Car/RV/Motorcycle/Truck/Boat/Solar Power System

I got this to use on a secondary car that is left parked for potentially long periods of time. I have a solar powered battery maintainer hooked up to it but I also wanted to easily check on its state of charge just in case. The BM2 fills that purpose perfectly. Installation is simple. You just clip its wires to the respective battery terminals and secure the unit somewhere safe (I just zip tied it to the top mounting bracket of the battery). After installing the app, it detected the monitoring unit and started reporting the voltage automatically. You can set alerts and also offers start and charge tests.It does use Bluetooth, so range is limited (especially considering it has a metal hood covering it normally). YMMV. Worst case, you may have to walk close to the car to get a reading. But at least you don't have to pop the hood or mess with the battery. It does keep a history which it updates to your app next time it connects, so you won't lose data points.All in all, it does exactly what I need.

Helped me diagnose a battery issue on my new F150. Turned out to be a software related problem that an update solved.

Easy installation, good bluetooth solution to monitor my cars' 12v battery charge via my phone. App seems well designed and works reliably

Works to help verify the voltage on my RV batteries. The only downside is you have to be close for it to work,maybe 10 feet. But it met my needs. We had to boondock for a few months and this helped me monitor my batteries. The features on the app are great.

Been using this for a year to monitor the 12V drain on my 2024 Ford Maverick Hybrid (seems to be a common issue with these trucks .... random discharging of the 12V battery. This monitor works well and draws almost no power itself. Only gripe is in the app when you look it historical voltage levels (up to 30 days old), the app does not allow you to zoom in to see a smaller window of time. that would be a HUGE inprovement. that said, the device works as advertised.

Why did you pick this product vs others?:Use this with my mustang mach e, works great. Install isn't bad at all.

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.

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.