Victron EnergyBMV-712 Smart Battery Monitor (Grey)

My previous battery monitor decided to quit so I took the chance and purchased the BMV-712 even though it was a bit more expensive. I'm so glad I did!This unit behaves wonderfully, just like the description. I currently have it on a 5kVA solar system with a 600Ah - 48v battery bank. I also purchased the optional temperature sensor: https://www.amazon.com/gp/product/B076MVPSMQ/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1I use the smartphone app literally 20+ times a day to check on the SOC of my battery bank, temperature, etc.. Aside from all the wonderfulness there are a couple quirks that you might like to know about before you purchase this.- One - the unit connects to your smartphone via Bluetooth. I have been impressed with the range, but the connecting time can be longer than I would expect. It takes on average 10-15 seconds to fully connect to the device. The closer you are to it the faster it connects. If I'm standing right next to it, 5 seconds, but if I'm next to it, I'll just look at the unit itself. Also, is has to reconnect if your screen shuts off. I have my screen-off timer at 30s, so sometimes that can be annoying.- Two* - the panel unit has +/- realtime power that can be displayed, but this is missing in the app, you can see realtime voltage and current, but it doesn't do the math for you in the app.*update* This was feature was added in a recent update of the app, so now it shows instantaneous power as well.- Three - The unit has a bunch of historical data you can view, but in my opinion it doesn't keep track of cycles properly. According to the current firmware version the battery needs to drop below 65% before a cycle has been counted. For example, on average our batteries discharge to about 80% remaining capacity everyday. Somedays more, some less. I've had this installed for over a month and it currently shows 3 "total charge cycles".- Four - It can only connect to one bluetooth device at a time, but even if the phone/tablet/computer is not actively displaying anything (screen off, etc.) it is still somehow "connected" and prevents another device from seeing it. This drove me crazy for a hour one day when I thought it's bluetooth had quit working. Turns out my computer was still "connected" because I had the app open even after the computer's display was sleeping. I even powered off the BMV-712 and it still was locked to my computer when it restarted. I had to quit the app on my computer before it would show on my phone. But what's weird is it would still need to "reconnect" and go through its procedure when waking up your computer/phone, etc.As I understand it, the programmers are working on a revision of the current firmware that will add in/fix some of these issues.The tech support is great, I inquired about the charge cycle issue and they replied within 10min. Very impressed. All in all, I still rate it 5 stars because it has a lot of very useful features and it just works. Easy setup/install. As long as you are aware/okay with the minor quirks, I think you'll love this little meter.

Great features make this a good monitor. Check instructions for proper installation and setup. The Bluetooth feature with the phone app is great and once set up makes it easy to modify settings and check numbers all on your phone. The feedback readings a quick to show on your phone, I can turn on a light and the monitor quickly shows the amps and other values related to the power used from your battery.

Works well, with great range. I can use it while driving.

Once you venture into lithium batteries you soon realize how different it is from lead acid and AGMs. Biggest difference being that lithium battery voltage remains pretty high during use with for example 12 volts being about 10% DOD. Therefore it is very difficult to estimate battery capacity using voltage for lithium batteries. The Victron BMV 712 has to be the best option because in all my searching I was unable to find a better option. It provides valuable information about power going both into and out of the batteries, the current draw both ways also, state of charge, voltage, number of cycles, number of full discharge, charged and discharged energy and so much more. The most important reading is the amount of useable time left based on the power and current draw from the batteries at any particular time, and this is constantly updated to reflect any changes in these reading. I also really liked that it automatically synchronized the full capacity of the lithium batteries. Another alternative monitor I looked at required that the batteries be discharged to set the zero capacity voltage. No need for this with Victron. I also have an Victron SmartSolar MPPT and was able to link the 2 using their smart networking option so they could share information. They both include Bluetooth monitoring which means you can easily see what’s happening and program it from inside the house using the app. Very pricey but worth the money. You certainly get what you pay for.