I have the following in vehicle 12v, house battery charging/monitoring system :

My AGM deep cycle batteries (360Ah) are charged through a DCtoDC 40A charger/mppt solar controller, connected to the vehicle start battery and 600w of solar panels. Also installed is a Victron IP22 240v to 12v charger.

I use a BMV712 which registers Amps used, when my fridge, lights etc are in use. I understand the 712 Current usage is Net ie Charge current going into batteries Less Current Used by Appliances/loads.

If my State of Charge is 75% and power is only coming in from Solar at 22amps, as shown on my Charger/mppt controller, with all appliances/loads switched off, the BMV712 shows 0.0 A.

Current used by appliances is correctly being registered. This results is SOC % battery capacity, always being understated and way below true SOC. So SOC might show 60%, just before the 712 hits the Charged Voltage setting of 14.3V ( Charger absorption voltage is14.6V), and auto syncs back to 100% SOC. Tail Current is set at 2% (7.2A) and Charge Detection time to 10 Minutes.

I suspect solar charge current is not being registered due to incorrect Shunt connection.

The LOAD connection of the shunt has :

1) one heavy cable, earthed to the vehicle chassis

2) Fridge Negative cable

All other appliances load/negative cables connect to a Bus Bar which is earthed to the vehicle body

The Shunt Battery connection has one cable connected to the connected batteries Negative pole. It's the first terminal on that pole, with the Battery connector terminal above it and the Charger/Mppt Controller Battery power Out Negative cable on top of that. Does this also need need to be connected to the Shunt LOAD terminal ?

BMV 712 smart monitor with progressive dynamics smart charger (PD4060). Only the coach battery connection, no temp or starter battery connected.

Lead acid 6V batteries.

Typically low usage, 1-5 AH, no usage higher than 5 AH.

Sometimes we have boondocked for a week or two and run the generator to charge when the battery got low. Often we are plugged into shore power.

I am seeing several readings that don't look accurate at all:

1) After boondocking 2-4 days depending on SOC, I run the generator to charge the batteries.

The BMV 712 shows running around 93/94 SOC and then instantly jumping to 100% state of charge. With lead acid I expect the SOC to take a very long time to top off (hours), not just jump to 100% instantly. What is going on here?

2) The SOC does not match the consumed amps or the voltage charts.

I understand the voltage drops when there is a load on it, yet our load is small so I would expect a small voltage drop.

I brought these up to the dealer early on and was told don't worry about it, you have low Ah usage so the battery lasts longer with that then it would if you used higher Ah usage - it is not a straight line. So trust the SOC.

Over time, these discrepancies seems worse.

Our battery is now showing signs it is failing which is unexpected for it's age (roughly 2 years old). I am concerned we have relied on the SOC following the dealers instructions when we should not have been.

Some examples:

2A)

80% SOC, current -3.1A

Consumed Ah -61 / 210 (71% left)

Voltage 12.26V (just above 60% in charts for lead acid)

2B)

62% SOC, current -1.3A

Consumed Ah -116 Ah (45% left)

Voltage 12.33v (65% roughly in charts for lead acid)

2C)

83% SOC, current -.3A

Consumed -52 Ah (75% left)

Voltage 12.73V (100% SOC in charts)

2D)

90% SOC, current -2.5A

Consumed -31 Ah (85% left)

Voltage 12.43V (below 80% SOC in charts)

2E)

95% SOC, current -1.3A

Consumed -18AH (91.4% left)

Voltage 12.37V (70% SOC in charts)

2F)

99% SOC, current -0.5A

Consumed -5 AH (97.6% left)

Voltage 12.58V (below 90% SOC in charts)

2G)

93% SOC

voltage current -1.1A

24 (of 210) consumed AH (would be closer to 88% SOC)

12.13 voltage (closer to 50% on charts).

Thanks for your help.

I have a BMV 712 smart. No solar. I use Victron Connect - ios app (tablet, phone).

I am looking for more detailed historical information. This app gives me only the current information, a history that is very limited, and trends only for the last 2 seconds (I can't figure out how to show a better trend graph). The demo showing only the BMV 712 is not working (stuck on asking for the password).

I looked at VRM and it looks like it would give more detailed historical data BUT it looks like I need the VE.Direct LoRaWAN. Is that true? I checked the LoRaWAN gateways and there is not one in the required distance.

We have a BMV-712 and want to buy a MPPT charger. Would it be possible to but a BlueSolar MPPT 75/15 (SCC010015050R) and connect it with a cable (VE.Direct) to the BMV-712 and get data from both of them in the app, or do we have to buy a Bluetooth dongle or a SmartSolar for that to work?

I observed an inconsistency of readings on my supervision, indeed the curve of percentage of charge went from 86% to 100% in a single blow (10 mins which is my sending frequency) while the sunshine was decreasing, here is a picture to illustrate:

[image]

Thanks

Maybe a dumb question. I have a lot to learn. I bought a BVM-712 to install in a new to me truck camper this weekend (2013 Lance 825). I will use the VictronConnect Android App to monitor. I note that the setup wizard will ask me to input the battery capacity. Unfortunately, I don't have a clue what my battery's AH rating is, and would appreciate advice on how best to proceed. The battery is a single 12 volt flooded lead acid. The label on top reads "MARINE-RV" ;"EXTREME CYCLE DUTY"; "Distributed by ABSS, Everett, WA." That, along with a yellow "8/18", is the only information provided. (I have reached out to the named distributer, but haven’t received a reply yet.)

My question is, how important is it for me to ascertain the battery’s capacity rating and input that into the app? Is it required for State of Charge and Time to Go? If I just guess, will the monitor self calibrate over time? If I should instead manually determine the capacity, any suggestions for how best to do that either using the BVM itself, or a DVM?

[image]

I have someone asking us to validate whether their non-Victron charger/inverter is treating the batteries well. All I could think of was strapping on a BMV-702 with temperature sensor and plumbing that into a Venus device (maybe a VenusPi) to log the battery data to VRM for a period.

Will the BMV work with Venus and VRM without having a Phoenix or Multi or Quattro or MPPT in the mix?

Today I updated all firmware for my components: CCGX, BMV-712, SmartSolar, and Multiplus. Before the updates, the BMV-712 was reporting the SOC just fine. Now the BMV-712 shows 0% SOC (and the voltage is correct).

Any ideas as to where to look/troubleshoot?

Why is it that I don't get VE Bus SOC [261]on the VRM ? I do get BAttery SOC {258}. Multiplus 5000/48V V4.33 , BMV 702 , Venus GX v2.33.

The boat I have has 2 Volvo D4 260 engines. There are 4 batteries. 1 is dedicated for starting the Port engine and the other 3 are for starting the Starboard engine and supplying the 12v power to the boat, therefore the starting amps will be going through the shunt. I cannot find out how many amps starting takes. What is the maximum intermittant power I can put through the shunt?

My two batterybanks are 25 ft apart. What is the best way of monitoring both banks with a BMV-702?

Hello,

I noticed that my BMV is calculating a too low SOC value (yes, it has been days since 100% charge reset), so I thought my currently set 1.05 Peuker's coefficient is too small for Tesla batteries. I adjusted it to 1.02 and to my surprise SOC instantly went down (?!) from 28% to 21%. Adjusted it back to 1.05 - SOC went back up to 28% again.

1. To my understanding, adjusting Peuker's closer to 1.0 should increase SOC not decrease it, shoudn't it?
2. Shouldn't the Peuker's coeff. be applied only during real-time? How is it incalculated into the SOC? Is BMV saving all historical Ampers that have flown through it since last 100% (I'd think that's highly unlikely)? If not, what's the formula? Consider that there's no temp. compensation, etc.
3. Is there a situation where Peuker's coeff. of, say, 1.02 not only decreases capacity, but can increase it?
4. Now I have set it to 1.0 to see how the SOC is being calculated without it. What params to use in BMV to make SOC calculation trivial as such (i.e. without no Peuker's, temperature, efficiency, etc. magic):
   
   (Consumed AmpHours / Battery Capacity) - 1
   
   If I do this calculation I get 30% SOC, which is closer to reality than currently reported 21% with Peuker's 1.0 and charge efficiency 98%.

Thank you for your insights!

Hi!

I have a BMV-700 on my LiFePO4 (100AH) Battery and i notice that the SoC is drifting heavily after days/weeks when i only have partial charging (Solar, only short trips with charge booster). Peukert is already set to 1.00 but it seems that the charging-efficiency is higher than 99% but in the App i only can set integer (not float) values for that. This results is too less AHs detected when charging. Last time i had a SoC show of 78%, then i plugged in a external charger, it loaded to 80% then the Voltage was 14.4 and current was 0A, so the battery was full. It then synchronised but it will not do that (and even can't!) when only have partial charge often. Any ideas? Also there should be a (hidden?) function in the BMV to calculate the charge efficiency, e.g: Fully load the battery with external charger. Discharge to let's say 50%, then activate the "calculate charge efficieny", plug in the charger again and then the BMV can calculate the efficiency (as it knows how many AHs were charged to reach 100% again). This should be possible, or not?

Can someone help me?

Regards

we can not find any detailed electrical specifications for the relay contact on the back of the BMV-712. We looked in the BMV-712 manual to no avail.

We can find only a summary on the spec sheet indicating 60V/1A. That spec does not specify DC or AC current and voltage, both of which are critical.

Could anyone point us to the location of the detailed technical specifications for the relay contact?

The bare minimum information we need is:

Maximum DC and AC voltage between the ground of the unit and the contacts

Maximum AC withstand voltage between contacts

Maximum DC withstand voltage between contacts

Maximum AC current capability

Maximum DC current capability (almost always different than AC current for relays)

Hi All

I’ve just updated my BMV 712 and now the soc reading is stuck on zero % , and not reading ah and hours to go. it’s reading the battery voltage ok

Any suggestions as to how to fix this would be gratefully received

Mojo

I have a Bmv and twin 150/35 controllers

Chargers will go into float each day but the bmv reading drops by ave 2% each day

Ive done a reset to 100% Next day 98% so and so on

Checked shunt Think that's ok

Any help

Hi. Will you add VE.Smart Network support on the IP22 Blue Smart Charger?

I own a BMV-712 with temperature probe and a MPPT solar charger which works really fine with VE.Smart Networking, so i think it would be really helpful to deliver the right battery voltage and temperature via Smart-Network also to the charger for temperature compensation and so on...

Thank you very much!

Hi,

I have bought a SmartSolar MPPT 100/20 and would also like to add a battery monitor to my system. I'm considering the BMV-700 as the 712 is out of my price range.

Is it possible to connect the BMV-700 to the Smart Charger via a ve.direct or other cable so that the BMV-700 can also be accessed by the bluetooth app through the smart charger? I understand you can add the bluetooth dongle but wondering if its possible to use the smart charger bluetooth instead via cable.

Thanks,

Dave.

My (new to me) setup is a 960Ah bank of Lead Acid batteries in an RV, with a Quattro, BMV 712 + 3rd Party MTTP Solar charger and a Cummins LPG (3 wire) generator.

I'm looking at using the 3-wire suggestion using assistants on this page (https://www.victronenergy.com/live/auto-generator-start-stop:start) however I was hoping to use SOC rather than pure battery voltage to avoid false positives if pulling a decent load from the batteries.

However, the assistant only seems to be able to use the SOC from the Quatrro and not the (as I understand it) much more accurate SOC from the BMV 712 (in this config with DC loads, alternators, 3rd party solar chargers).

Is there any way around this or should I be looking at another solution?

How hard would it be for VictronEnergy to have a post, page, what ever... listing the latest updates for their devices and app?

Wanting to find out if others have had success in gaining an audible after upgrading to rev 4.03. I've upgraded and still can not get an audible alarm on low battery temperature alarm, display indicates the alarm.

My BMV 712 smart is set to alarm on high voltage via the battery settings on the unit. On high voltage however, the display flashes and the alarm symbol shows but there is no noise. The buzzer is set to 'On' via battery setting 32. How do I make it so the buzzer sounds?

Any ideas?

At the moment, my first thought is that since the BMV is being powered via the sense cable and shunt, the additional 5v feed from pin 4 of the ve.direct port on the MPPT controller is unnecessary, and that since something odd is clearly happening there, I will get some JST-PH connectors and make up a little extension that goes between the mppt controller and cable, with pin 4 disconnected and only the gnd, tx and rx wires connected. I'm thinking this is most likely going to fix it, but even so I'd like to know what's going on here.

I have a BMV-712 connected to a 450 amp hour lead acid battery bank (Trojan t-105’s). Recently When I run my battery charger to bring the batteries to a fully charged state I’ve noticed that the consumed amp hours still read 40-50 amp hours consumed when the BMV synchronizes and resets the battery to fully charged and resets consumed amp hours to 0.

in other words I’m using 100+ amp hours over night but only registering a return of about 50-60 amp hours back into the bank when I fully charge them.

Is this normal?

Both my solar and my AC-DC battery charger bring the batteries to 14.82 volts for a specific time based on previous day’s discharge and then reduce batteries to 13.5 volts with minimal amps to sustain this. I have adjusted my battery settings because before I was getting fully charged status too early.

[image]

Hello,

I recently purchased a sailboat with a BMV-602S Battery Monitor. I was wondering if anyone has had luck with the VE.Direct Bluetooth Dongle or NMEA2000 drop cable working with a -600 series unit.

The compatibility list for the bluetooth dongle only lists -700 series BMV Battery monitors, but the interface/plug on the back of the -600 & -700 series monitors looks the same. Before I buy one, I'd ilke to know if it'll work for my BMV-602S monitor.

Thanks!

I have my TPS1230 solar controller connected via my VictronConnect BMV 712 smart battery monitor. The TPS shows 7.5 amp solar imput however the VictronConnect shows only 5.2 amp imput. Why would there be this variation and which is the correct reading? Many thanks

Hello!

I have a Smartsolar 100/20 and I'm looking at acquiring a BMV-712 and associated temperature probe.

Currently the Smartsolar is connected to a Raspberry Pi via the VE.Direct USB cable. If I bought a BMV-712 and connected the two via bluetooth/smart networking, would the VE.Direct messages from the BMV appear on the VE.Direct interface of the Smartsolar, or vice versa, or would I need to buy another USB cable to be able to recieve data on the Pi from both?

I'd much prefer to not have to get another cable as USB ports are at a premium in my setup!

I have a fairly new installation (July 2019) of a 200ah battery and a BMV 712.

I’ve the last week or two I am noticing that the % reason on the BMV seems off from the actual voltage reading.

EG SoC is 51% and Voltage is 13.26

I know my fully charged voltage (SoC 100%) is 14.4 volts but can’t find any list of voltages for lower SoC.

Is there a way, list, or calculation that will show me the _real_ SoC for the voltage at the battery.

My system is:

Multiplus 3000

200amh Victron Lithium battery

Victron bms

Battery protect X 2

Sterling Power Dc charger.

All fitted in my Motorhome where we live full time.

TIA

It's starting to get cool here so I'm thinking about my LiFePO4 batteries. I have a Victron 100/50 MPPT and a Bmv712 connected via VE network and I have the BMV temperature lead connected to a battery terminal.

The MPPT is set to 5°c cut off but can you confirm this will prevent any charge going to my batteries until they get above 5°c?