BMV Battery Monitor

Hi there,

I am trying to figure out some basics of my system. I have a 12 12 / 30 Orion that is not the “smart” newer one. I have it hooked up to a remote switch so that it turns on (green light) when the alternator is running.

I have a battery monitor hooked up as well. When I shut the batteries off and turn them back on it always says “100%” regardless of how much was used previous time. Im guessing 100% is just whatever is currently in the battery bank when battery monitor starts up?

I just want to see if the Orion charges and how much! Any tips much appreciated.

Hi, Sorry if this is a common question, I'm very new to Solar and trying to learn. I'm very impressed with my Victron gear but there is 1 problem.

I watched the Victron video explaining to change the BMV settings and have done so however the SOC detection still doesn't seem to be working...hope someone can offer some advice.

Setup:

120Ah "Fusion" brand battery

110W Solar Panel

BMV 700

MPPT 75/15

0.8A load

VenusOS on a Pi 3B+ with 2 x USB to VE Direct cables

The battery seems to be charging fine, I can see bulk then absorption then float phases. Unfortunately the SOC never gets reset at all, it just gradually declines until it's zero.

I haven't changed anything on the MPPT, it's by default at Factory default "Gel Victron deep discharge 2".

The BMV I have these settings:

Battery Capacity: 120Ah (I changed this)

Charged voltage: 13.5V (I changed this)

Tail Current: 4% (default)

Charged Detection time: 3m (default)

I set the charged voltage at 13.5V because I can't find the battery stat for this on the manufacturer's details so I looked at the average figure during absorption phase, 13.8. Based on this I set charged voltage at 13.5, 0.3 below absorption rate per video instructions here:

https://www.youtube.com/watch?v=4ReljfO3k6M

I guess I must have misunderstood something, can anyone help?

Thank you.

My Lead Acid OPzS battery bank is "becoming smaller" as I continue to load the system more an more. Initially I sized the system for 20% DoD, but now in next winter I am afraid it may reach 40 to 50% or even more.

I have now the chance to get a good priced set of Winston LiFePO4 90Ah cells and I was thinking to build a smaller independent system to offload some of the work of the main system.

I allways thought it would be not advisable to put lithium in parallel with lead acid, but the more I think of it, the less crazy it seems. My LA system is 24V based, the 8 cell Winston would be 25.6V nominal. I would source a 3rd party BMS to manage the lithium. Maybe the BMS can take care of the issues - disconnect in low and high side of the daily swings.

I actually have found a product to make hybrid battery banks (BOS - LE300) so maybe this isn't so crazy after all.

To install in parallel and monitor the 2 strings I was thinking if it would be possible to use a separate BMV on each string (Lithium and OPZS). Is this possible, using 2 BMVs on same Venus device?

We have a BMV-712 that seems to have intermittent problems with 30' USB Runs to 2 MPPT Controllers. We've tried 2 different powered USB hubs (on the MPPT side) and 2 different USB cables (with booster chips) to no avail. I've unplugged the USB WIFI dongle because it too seemed to be dropping out intermittently. Everything is patched to the latest firmware. Here's what I'm wondering:

1) Is there is a known problem with longer USB runs?

2) Is there possible a problem with my BMV's USB interfaces?

3) Would a powered USB hub on the BMV side be better placement to amplify the signal to-from the MPPTs?

Many thanks!

-Steve

I have four 100ah lithium batteries that I plan to wire in parallel, and I would like to be able to monitor them (at least charge status) with my BMV-712 monitor. After searching through some of the posts here and also trying to look through the manual and quick installation guide, the answer is no clearer to me. I'm having an auto electric shop relocate the batteries on our RV so all four of them reside in the same compartment, but I'm not sure how or where to wire the monitor. Thanks for the help.

Hi there,

I am in the middle of setting up my first pieces of Victron gear with my lifepo4 100ah 12v battery.

I love the features and the quality construction but I do have a question.

I am seeing different voltages across my victron gear and readings from a multimeter.

1. BMV712 reads 13.34v
2. SmartSolar 100/20 reads 13.33v
3. Multimeter reads 13.28v

i have taken multimeter readings from various areas. The battery terminals, from the terminal and the shunt and from the mppt terminals. All readings are 13.28v

I have seen comments that there could be an incorrect fuse in the BMV712, but I’m also wondering what could cause this?

I have no long runs of wire and I have checked the crimping on my connectors.

My primary concern is the the mppt charger will stop charging too soon.

Thanks in advance for your help.

Bonjour le cable ve-direct du bmv 702 vers venus GX à était coupé par erreur. Soudure et code couleur ok .Une fois remis le bmv est plus reconnue par le venus . Mise à jour vérifié par Le VE.Direct Bluetooth LE dongle de Victron Energy. Rien ne change, je n’arrive pas à le reconnecter . tout fonctionnait bien depuis 3 ans . Qui a une idée ? Merci.

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I will be capacity testing some new Lifepo batteries in the next couple weeks and was hoping to use my smart shunt to measure and capture results. The tests will run until the BMS shuts down the battery based on a low voltage cutoff (at the cell level, not the battery voltage).

I did a bench test last night and found that when I cut battery power, my smart shunt data/history is gone and I can't see the consumed ah's where the BMS disconnect happens.

I would think the data would persist somewhere, but I can't find it. Is there a way to write off the data to a permanent record somewhere since it appears to be wiped after power is cut? I don't care about capturing every single data point at the end, but would like to get a good idea of where it ended up before low voltage shutoff.

I was also trying to think of a way to power the shunt with a small current from a power supply separate from the battery, but I think that would skew the test and would cause a problem when the battery shuts down since the inverter would still be trying to pull a load when the battery shuts down.

Any thoughts? Thanks.

Hi All -

Relay wiring and documentation for the BVM 712 Smart are desperately lacking. I have a power protect and a 712 on opposite sides of a teardrop camper with only a single wire available connecting the two.

I am trying to figure out:

1. what the three three relay terminals on the 712 are for / how used?

2. In the app there is a "remote" option for relay mode

Neither of the above are mentioned in any of the documentation.

I am hoping that "remote" mode will send a 12v+ connection across my single wire so I can manage low/over voltage disconnect of the power protect with my 712.

Recommend adding any information around this to the documentation.

Thanks for the help and advice.

Section 3.4 of the Victron BMV-7xx manual says "The battery state of charge indicator scales between the configured discharge floor and 100% state of charge and reflects the effective state of charge."

Is this saying the discharge floor setting does impact the XX.X% SOC display and/or the battery-fill [====] display?

The BMV manual seems pretty clear that the "discharge floor" setting DOES impact the "time left" display. The BMV manual seems contradictory if the "discharge floor" setting impacts the SOC and battery-fill displays however.

Thanks,

--tg

I am a little confused and have read my tips which sometimes have been conflicting and confused me more.

If feasible I would like to have a Battery protect to prevent a charge from dc-dc orion, MPPT and the IP22 charger. The intention is to set up the relay parameter in the BMV712 and when the temperature or voltages are outside certain parameters ( below 5 degrees) the Battery protect, using the remote feature, would turn off.

I would like to know if this is feasible?

[image]

and if this is ok which connections do I need to make?

The objective is to protect my lithium battery against charging at cold temperatures.

I have included a diagram of my setup which does not have the BMV to Battery protect relay connection.

Also attached is my current setup, which shows the 2nd BP-65 not connected and this will remain like this until I can found the correct safe solution.

Any help much appreciated

BP2.pdf

While bulk charging batteries alone, PV output stays at about 1400 watts. When a 700 watt load is turned on on the multiplus, PV output mysteriously falls to about 900 watts.This occurs while still in bulk charging mode. One of my mppt's is throttled down to very low output even though it's in constant sun.

I'm running 3 Smart Solar MPPTs,BMV-712, a CCGX (DVCC on, SVS, STS, SCS on, Max charge off) and a Mulitplus compact connected via an MK3.

Any suggestions to fix this and keep the 1400 watt output from being throttled down?

Hello together,

iam a little bit confused about the misc settings about the shunt current and voltage.

Can someone advise how to set this values ?

Even, a free set value are possible.

[image]

Thanks in advance.

Best regards

Dear Victron-fellows,

I have 2 questions about adding a Smartshunt to my system. The picture displays a simplified situation: 2 batteries in parallel, fed by a dynamo, Multiplus and MPPT (via Argofet). Now I want to add the batterymonitor and 2 questions have risen:

- Does it make a difference (or is it good or bad) on which of the 2 batteries the VBatt+ of the shunt is connected (A or B in the drawing)?

- I know I have to connect the shunt to the battery-minus without any other connections on that side. Since I have 2 batteries in parallel, I suppose the right position is C? Problem is that there is hardly any space over there where the minus-cables comes together and I have to use long(er) cables. On position D it would be much nicer (together with A for the powersupply / +). Is this a go or a no go?

Hope to hear from you

Kind regards,

Pim

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I am looking to use the bmv712 and the supplied 500 amp shunt with the ve.direct output and reading the output with an arduino. My question is the bmv712 specs indicate amps accuracy of .01 Dc amps. I am trying measure very small currents say .25 amps up to a maximum 100amps, will the bvm712 measure dc currents that small and output them in the ve.direct port ? The dealer I contacted said it was only good for + or - 1 amp.

thanks

I have completed my install of

• MPPT 100/30 controlling 2 -170 watt panels wired in series
• BMV-712
• And 4 Victron 6V/240Ah AGM Deep Cycle BAT406225084

My problem is figuring out the best settings on the MPPT and BVM. In all my reading I am more confused, much less the fact on the MPPT there are two options for the Victron deep discharge and an AMG. Not to mention on the BVM things like Peukert, charge efficiency, ect.

I just spent a lot of money on all of this and want to get the most out of it and the best battery life.

Hello, since the latest Victron Connect update to v5.38, the Time Since Last Full Charge on the History page for my BMV-712 Smart no longer updates, but reports 0 seconds continuously, even after the batteries have synched to 100 per cent. Everything else seems to be working as normal. Just wondered if this is a bug in the latest software and if anyone else has noticed it?

I have an older PWM charge controller which will charge both the House and Starting batteries. I am getting more solar panels and want to upgrade to MPPT, but MPPT charge controllers generally do not support 2 battery banks.

• Assume I start with a single MPPT SmartSolar or BlueSolar controller

What would be the best solution?

1. I could use the Load Output and wire that directly to the starting battery, and set a rule for the Load output to turn on the load when the house battery is between X and Y volts. Pros: doesn't require more equipment. Cons: the bigger MPPT controllers don't have the Load output at all, so I'd have to stay with the lower capacity models.
2. I could get a BMV 712, and use its relay output to control a relay which connects the House and Starting batteries, and use a similar voltage-based rule (On between X and Y volts)
3. Some other Victron product - battery isolator or combiner or...?

Thoughts?

I have installed a new BMV-712 on my camper that has 2 x 12v 115AHr AGM's in parallel. I also have a separate Volt/Amp meter installed. The BMV reads current lower than what it actually is. 3-5 Amps on Charge and Discharge. 10mm cable used to connect the shunt?
I have no idea if the BMV is just not a very accurate device or how to investigate the problem

Hello ! I would like to know how to connect my BMV-712 24v with the smart battery contact 220 24 v and victron battery balancer 24 v
My battery pack is composed of (A) 2 6v batteries in series coupled to 1 12v battery in series with 2 6v batteries. = 24 v (B) 2 other 12 v batteries in series = 24 v
then A and B in parallel for 24 v total. I don't understand how to connect it all together.
Thanks for your help Claude

Bonjour ! J'aimerais savoir comment connecter mon BMV-712 24v avec le smart battery contact 220 24 v et victron battery balancer 24 v

Mon batteries pack est composé de

(A) 2 batteries 6v en série couplé a 1 batterie 12v en série au 2 batteries 6v.= 24 v

(B) 2 autres batteries 12 v en série = 24 v

puis A et B en parallèle pour 24 v total.

Je ne comprends pas comment connecter le tout ensemble.

Merci de votre aide

Claude

I have 4 12v AGMs wired in parallel/series for 24v bank with their midpoint monitored from my BMV-712. In the past month or so, once or twice a week I get a midpoint voltage alarm when I discharge below 74%.

[image]

The batteries are less than a year old and I think I've taken care of them pretty well, never getting them below 60%. It's very weird that the midpoint voltage doesn't deviate /every/ time my bank is discharged, only some times. For example, in that graph the midpoint voltage was totally fine on the deepest discharge on february 12. In addition, I am sampling from one of the two series midpoints, and it is not linked to the other one because I read here that it could be bad if one of the batteries totally fails. Should I try connecting the two midpoints? Or is there anything else that might be causing his behavior? The batteries never get below 45-degrees.

See video attached:

Before the update, when I switched off my battery, the BMV712 use to show 0Amps being withdraw from the battery.
This week I have updated the firmware to the latest one and now its showing Amps moving in both directions and in a very weird pattern.
I have no solar and the boat is not connected to shore. How can the BMV show that the battery is charging??? Everything worked well for the last 2years.
How can I downgrade my the firmware to the previous version?
What you see on the video is happening with the main battery switch off.

Hi i have a dcdc 12/12/30 and a 100/20 solar controller, the solar controller works fine without the car running, when the car is started the DCDC kicks in but at a reduces amp input, for example solar input 10amps dcdc running total showing 20amps so the dcdc only adds an extra 10amps, i also have a BMV712 connected, maybe the setting on all three are conflicting?

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

I updated the firmware whole the batteries were arou d 16-20% charged. It then read 100% after it updated.

I have two 200AH Lithium Ion batteries connected.

I am afraid of overcharging the batteries by manually choosing an estimated SOC, but I'm also afraid of over-discharging by NOT manually changing the SOC and them not charging above their current SOC because the system thinks they are at 100.

I guessed the SOC had charged to around 30%, so I manually changed it to that. Will a wrong guess damage my batteries as the system charges and then discharges???

What should I do???

Somebody please help. I attempted an update and didn’t loose connection. Current version says 4.05 even though at failed but now the consumed ah says - -. The app suggested removing it from my device but I can’t see how and I don’t want to loose all of my data in there.

I wanted to go to the settings - but the app told me I needed a firmware update before I could do that. So I updated - And then my phone locked and lost the connection.

Now everything is working except for the state of charge.

The product info says that I have the latest (4.3) firmware, so I can not update again.

Is it possible to re-update to fix the problem?

When I test the voltage at the controllers terminal screws it shows 66V (I'm using 3x 20W panels in series) - In the app its only showing 12.7V; which means my 12V batteries won't charge. If I connect each individual panel to the controller it still shows 22V at the terminal but still only 12.7V (each one shows the same) in the app. Is my controller toast?

Hi folks!

I have the MPPT 100/20 48V Solar Charger up and running, charging a 48V Li-Ion battery pack.

The OCV for Panasonic GA cells (13 in series) is going from 42,3V (SOC = 7,5%) up to 53,9V (SOC = 97,5%); This is the working range.

Now I am trying to find the best settings. Could you please help me with that!
How should I set
- absorption voltage
- float voltage
- equalization voltage (really needed for Li-Ion?)

- Re-Bulk voltage offset (what is it for?)
- Absorption duration
?

Thank you very much in advance!

Regards, Flo

By any chance somebody knows if all 6 cables are used at a BMV700?
Or if 4 cables are enough, what I assume (typical in these kinds of connections in electronics)?
Curious! :)