BMV Battery Monitor

I am having an issue with my MPPT 100/50 charge controller reading the wrong voltage, which in turn does not fully charge my battery bank. The charge controller is networked with a SmartBMV battery monitor. The charger controller receives battery voltage and temperature from the battery monitor through VE smart networking.
For example, my battery monitor is reading 26.45v. This is the correct reading, verified by a volt meter and consistent with the state of charge. When I log into the charge controller, the voltage is reading 27.26v. This is WAY high!! This stops my batteries from fully charging. If I sit there in the app and watch the battery voltage for a while, it will sometime dip down to ~26.8v and then jump right back to ~27.2v. When this happens, EVERYTHING is off. No charging or discharging. Battery monitor voltage does not move and stays right around 26.45v.

I thought maybe the battery monitor was sending the charge controller the wrong voltage, so I removed the VE smart networking between the two devices. So now the charge controller is reading the voltage for itself. The charge controller was still reading around 27.2v. Nothing changed. Reconnected the network, charge controller was receiving the correct battery temperature, but the voltage was again high, around 27.2v. Do I have a bad charge controller? It is less than a year old. I am not a novice at this as I have an undergrad in mechanical engineering and a master’s in industrial engineering. My day job is mostly electrical engineering. This issue is starting to drive me nuts. Am I missing something? Is this a known issue? Firmware on both devices are up to date. Battery monitor v4.03, charge controller v1.46.

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Hey Everyone,

I am in the middle of a van conversion. I've got solar, shore power and alternator for charge sources.

I was curious about how the devices in my charging system decide which source to charge from and if they are smart enough to realize that the system is already being charged by another device already. I don't want to jam too much current into my batteries.

My current setup is:

-200AH (100AHx2) AGM batteries (wired in parallel) max charge current is 60A

-310W Solar Panels

-Victron BMV-712

-Victron SmartSolar MPPT 100/30 Smart

-Victron Orion TR smart 12/12-30 Charger

-Kisae IC-122055 AC Charger/Inverter (55A Charge) - Shore Power

https://www.kisaepower.com/wp-content/uploads/2016/07/Inverter-Charger_datasheet_high_frequency.pdf

-Victron Smart Battery Protect - I was thinking of using this to turn off all DC loads with the push of a button.

Scenario 1: If I am plugged into shore power and the sun comes out and the MPPT decides to start charging at the same time, I could see a very high charge current (80A) with both devices trying to charge at the same time, correct? Or would the MPPT somehow detect the charge voltage of my Inverter/Charger and not start?

Scenario 2:

The van is charging from the MPPT and I decide to go for a drive. I start the engine and the Orion decides to start charging. Technically this scenario wouldn't exceed the max charge amps of the battery but I am just using it as an example.

Am I overthinking this?

I have got BMV712 Vers5.19 an Android 9.0 for two month in work without any problems. Suddenly the app can not find the BMV. I can see the BMV in android bluetooth settings. Its not peiring. In App settings i can see there was an update 7 days ago.

What i already tried with no success:

new installation of the app, search for any updates for the app, restore network settings in android, disconnect and connect networkcable from BMV (unfortunatly all settins lost), go in the airplane mode in android for some minutes and back, reboot the phone several times.

Have somebody experience with this issue ? Thanks great for helping.

I have a BMV-712 which monitors the state of charge of an 800 Ah lithium pack. This is installed on a liveaboard boat and is charged purely from solar. Day to day the soc remains within the range 30-80% and is in continuous use. I recognise the issue of drift and as a result each month I bring the soc up to calibrate the BMV back to 100%. I have the reset conditions quite tightly controlled, the BMV needs 13.7v (absorption at 13.8v) and a 2% tail current for 6 minutes. This reset always occurs ‘prematurely’ ie at an indicated soc of about 92%. I know I cannot avoid soc drift; however, for it to be consistently in one direction makes me believe the situation can be improved by changing my settings. Since, at the end of the month the BMV is underestimating the true soc I felt that I need to increase the charge efficiency factor. I already have this set to 99% and changes are only available in whole numbers. Could I ask that you confirm my logic and if I am correct is there any chance we could get a software update to introduce more precise settings for the charge efficiency factor?

BMV-712 SOC is always wrong. 3 Battleborn Batteries.

Hello everyone. I sure this has been covered somewhere but I haven’t found the answer yet.

I have the BMV-712 smart monitor and it seems it’s never correct on the SOC. I have charged the batteries several times to full charge. During this process I run nothing off of them and charge them to the point it shows 0.2 Amps or less going into them and 14.4 volts. At that point I synchronize the BMV to 100%.

Now one would think the SOC would go up and down correctly with the voltage but the BMV-712 shows a low SOC all the time.

All of the settings are correct for the battleborn batteries firmware is up to date.

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The system has 800 watts of solar and generator that can charge the battery bank.

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One would think that when the system is charging and it’s only dumping in 10 amps via the generator it would show it’s nearly full on the SOC. But it always seems lower then expected.

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So if anyone can please give me some ideas on what makes or ideas on what to change or make adjustments to I would appreciate It.

Thanks in advance. Crazy Marty.

I cannot discover my new BMV 712 with the Victron Connect App on my iphone. Setting 71 is not shown when I scroll through the settings, they skip from #69 back to #1. Any suggestions out there?

I have two independent systems; one 12v and one 48v. They are connected to the same Kohler generator for off grid charging.

For the 12v system I want to use a BMV-712’s generator auto start function when the 12v system hits the discharge limit.

For the 48v system, I want to use my 48/10000 Quattro or Cerbo GX‘s generator auto start function, when the 48v system hits the discharge limit.

Is this possible to use the BMV-712 and the Quattro/Cerbo GX in parallel on the genset remote start circuit? Which is the preferred trigger output for each system? I assume I need a diode on each output?

Thank you in advance for the advice.

I have 2 24v batteries connected in series for a 48v system but one of the 24v is getting more charged than the other. Currently I have 2 150/35 MPPT controllers in parallel charging the 48v battery and it's monitored by a BMV-712 which needs to be the only thing connected directly to the negative 48v terminal to track the current in & out. The negative terminals for the solar panels & the MPPT controllers (both for solar in and the other for battery out) are connected to the chassis (to reduce loss from heat/save wiring, this is in a motorhome - side question: is this helping or hurting?).

1. If I connect the +/- terminals of one 24v battery directly to the +/- of one MPPT controller (and do this to the other 24v battery too), will this work or short? If so, how is the + terminal in the middle (of the 48v set) connected to the - of the other battery protected against a short when that - terminal is connected to the - of the MPPT controller?
2. Should I use a battery balancer for this issue instead?
3. Whether balancing with a balancer or using the MPPT controllers on the individual 24v batteries, how will the BMV accurately track current unless it's the only thing between the battery and ground?

I am wondering if my BMV-712 settings are optimal for 960ah of LiFePO4 12v battery array and 1200 watt solar system using an MPPT 150/85 controller. Thank you!

BMV Settings for Solar:

Battery Voltage: 12V
Max Charge Current: 85A
Absorption Voltage: 14.5V
Float Voltage: 13.5V
EQ Voltage: 0.00V
Re-bulk Voltage Offset: 0.10V
Absorption Duration: Adaptive
Maximum Absorption Time: 30m
Tail Current: 2.0A
Equalization Current Percentage: 25%

BMV SOC Settings:

Battery Capacity: 960ah
Charged Voltage: 14.2V
Discharge Floor: 50%
Tail Current: 4.00%
Charged Detection Time: 1m
Peukert Exponent: 1.05
Charged Efficiency Factor: 99%
Current Threshold: 0.10A
Time-to-go Averaging Period: 3m

Hello everyone.

Re the newly announced Smart Shunt, I'm wanting to understand what it doesn't do compared with the BMV-712.

I'm working with my boat builder to design and install a large Victron lithium battery and electricity management system, based around 4 x 12.8V 300Ah Smart LiFePO4 batteries. I had specified a BMV-712 and its included shunt (500A/50mV).

The documentation on the new Smart Shunt says:

Hi

My batteries are going into FLOAT every day but the dsplayed battery capacity % is gradually reducing over a few weeks (ie, the batteries are not degrading).

What is the likely cause?

Should I have to reset 100% SOC frequently?

Is my shunt installed correctly with respect to the 12v fuse block? The shunt is out of picture but is in the negative cable leading out of the bottom of the picture.

thanks

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hy

i have a probleme with a bmv 700

one off my customer make a discharge test on a systeme with 24 V (2 bat agm 125Ah) .

he had fully charged individualy the batery before start the test.

the test start with a soc at 100 (on bmv and in real because the 2 battery was fully charged)

you can see below the test:

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the probleme is he had just loking the soc and suddenly, all system broke done.

the theorical consumption is minimum 0.4A, the real cunsomption see by the bmv is 0.4 A

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so if we calcul the Ah used, we arrived around 120Ah so it's look corect with the 125Ah off the battery, but the soc calculed by the bmv (around 50%)when shut down) is not good.

i had checked the bmv parameters, but it'look ok:

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during the test there is only bmv, venus and the load conected and nothink conected between the batteri - and the shunt .

i don't anderstand why the soc is aproximatively 50% faults.

do you have an idee ?

best regards

I know the shunt uses m10 hex bolts, but what is the length and pitch.

What is the max length of the UTP cable for the BMV 712?

Other than having an RJ12 connector with all 6 wires in a straight through configuration, are there any other requirements for this cable?

I have a multi plus 12/3000,connected to a BMV battery monitor and a CCGX colour screen - when on shore line the batteries charge normally and the CCGX shows 100% charge batteries full. However when I disconnect the shoreline and run the engine over a four hour period the batteries are going down as well as the percentage - have had the alternator checked and the cables from the batteries to the shunt have been tested with a clamp meter for the amps and voltage but the equipment is not detecting any amps volts etc - any ideas?

Hello, i am installing a boat with a two bank 24v system switched 1/2/both/off. Also a victron split charge diode which requires both banks -ve to be permanently linked. I have bought 2 bmv-700 monitors as I would like to have visual information on both battery banks at the same time. Will this work and which side of the 2 shunts should the link cable be on?

My smart BMV-712 is telling me that my batteries are at 40% and that the time left is just a few hours. The problem is that I know that the battery are fully charged. How can I fix this? I think it should be an adjustment somewhere, but I can't figure out what. Help please. Thanks

I have an Easysolar 48/5000/70-100 with CGX and seperate BMV 702.

I notice that there is an installed battery temperature sensor to the EasySolar, and I assume that is part of the charger (it is not the optional BMV one). I would like to know if it is possible to configure the system so that that temperature information feeds the BMV state-of-charge calculation?

Have a 48 volt system using lithium powerplus batteries on a quattro inverter. BMV will read 54.2 volts and CCGX will show 55 percent, wondering why they are not matching up.

cheers

i have power supply for vehicles include 200 amp LFP battery ,Cyrix, LVD ....etc, and using BMV 712 smart for display current ,voltage SOC % when dismantled the system and installed it on anther vehicle the SOC reading = 0% but the battery voltage = 27.9 v = 100 % SOC i need to know whats happen for the BMV?????

Why did my battery die.

I'm asking this question to find out what went wrong and how to correctly maintain solar charging of AGM VRLA type batteries in a mobile scenario.

Setup purchased Dec 2018 (14 months old)

2 x HGL-120 -12 PRO SERIES EXIDE VRLA AGM.
1 x Victron 75/15 mppt
1 x Victron battery temp sence
1 x 100 watt solar panel.

Batteries are in parallel, charge cable from mppt is connected to + on one battery and - on the other.
The mppt settings from new have been, absorption 14.3v float 13.7v. Having some concerns over this near default setting about 3 months ago I changed these and made a new user defined standby setting which allowed the battery to achieve a float without major charge. info here

https://community.victronenergy.com/questions/29395/firmware-update-v142-causing-different-charging-ti.html?childToView=29432#comment-29432

The van has been used very little, 3 camping trips, a week each time and 10 other times overnight all with minimal discharge from a 45 watt fridge and a few other small gadgets.
January last was the third week trip to forster, it's then I noticed my discharge was more than normal down to 12.7v and charging back to float was hard to achieve, a bit concerned I started to wonder what was happening.
today with settings on default the voltage wouldn't rise above 14.1v and bulk charged up to 6 amps through the day, after chasing symptoms on line I physically checked the batteries and found the one without the victron temp sencer was hot hot hot, cooked. The other with temp sence was warmer than normal at 35 degc, I suspect it's been warming by leaking power to the dying one, I disconnected the batteries and checked voltage cold battery 13.19v the hot one was12.9v and checked an hour later 12.6v.

I must say I have spent hours of research trying to do everything for this not to happen and here I am, so I ask the question why did my batteries die.

My BMV-700 shows battery voltage as 0.00, even though it is 12+ volts. It does however show Amps in/out. I found that the left most pin on the PCB board on the 500A/50mv shunt is corroded and has no "spring" left in it to make contact with the UTP communication cable.

Can someone tell me if the left most pin on the UTP connector is used? If not, what else could the problem be?

If I do need the left most pin to work, where can I go to get a new PCB board?

See pictures below. Thank you.

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Made a mistake yesterday. Pushed the sync buttons when the batteries were only 82% full. This has changed the battery capacity to 100%. Now I can't undo it. How do I get the charge to return so I know the batteries are full.

System is:

4 x 6vDeep Cycle batteries in series and parallel giving 12v and 500Ah capacity

Charge voltage set at 13. 6v

Tail current set at 4%

Everything else set at factory default.

Any suggestions how to get batteries back to their true 100% capacity?

Thanks

Kiwibev

Hi

Advice needed on 2 areas

Background.

Question 1

I do a lot of shows and off grid stop-overs, apologies upfront and bear with me.

Original setup was Smart Solar MPPT 100/20, 110AH leisure battery, SmartSense using VE Smart Net. But the demands on load increased so added a second leisure battery and Smart Sense battery monitor in parallel , this is where things started going wrong. Batteries were connected in standard - to -, plus + to +, Load battery A -, Battery B +

In this configuration from what I understand you can only use one BatterySense which means you cannot synchronise/monitor temperature on both batteries. (Batteries are contained in their own battery boxes)

Further complicated as needed to increase load still further so I replaced the inverter, as such I wanted to protect batteries to a maximum current drawable from each battery, so changed cabling so both batteries are now fused and connected by bus bar using same length cables (+ and -), as you would in 3+ battery configuration to maintain balance, also as I may add additional batteries in the future.

I have now added a BMV712 Smart into the mix, which measures current and voltage at bus-bar point rather than battery point, but the documentation says you cannot use the BMV 7xx with smart sense monitors. Even if you use the BMV with temperature sensor, you can only measure temperature on one battery??? So charge/temperature algorithms will only will be based on one battery not both or more.

I'm at a loss on what to do for the best?

Question 2

I currently am looking to replace the current DC-DC charger for the Orion-Tr smart 12/12 (30), Does anyone know if there are any plans to include support for VE Smart Net.

Any advice is very much appreciated.

Rgds

I have a BMV 700 connected to the Venus GX and working fine for about 6months what worries me is it keeps on resetting to 0.0 on the screen and battery icon starts to flash and i cannot see any data from it. I will have to plug of cables from the back to restart it each time this happens in a day or 2

Just purchased the bmv712, trying to install on my motor home but I think I’m overthinking it. I have a redarc bcdc1240 charge controller, which runs my solar and converts my alternators 24v to 12v while the bus is running.

Question is; 1: is the instal as easy as cutting my earth wire, and running end to the shunt

2: does the bcdc charge controller earth have to be connected to the shunt directly?

Thanks in advance guys and girls

Hello,

I have a motorhome with (2) 12 V AGM batteries and a Victron 712 to monitor them. Everything was working correctly until I let the batteries become discharged.

I removed the batteries & charged them fully outside of the vehicle. I also had my battery dealer test them (the batteries are less than two years old). When I installed the charged batteries in the motorhome, I ran the on-board generator to top off the charge.

With the generator running, the voltage shows 14.2, but the current wavers between zero & 0.2A. I get the same readings if I run the motorhome's engine. The manufacturers of the converter/charger and the battery isolater had me check a few things & they both appear to be working. When the generator or motorhome engine isn't running, the 712 shows a negative current amount.

Any suggestions on why the current reading is essentially nonexistent?

Currently I have a BMV-712 mounted in my RV battery compartment. The display faces horizontal. I only receive the BT signal in the coach with my phone laying on the RV floor. I am thinking that I may be able to rotate the head unit to obtain a better signal inside the coach.

In which direction does the BT signal transmit from the BMV-712 ?