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BVM 700 discharge floor %

I have a bmv-700 with a bluetooth dongle monitoring four 64ah lithium iron phosphate house batteries in parallel in my rv. I am trying to find the definition of "discharge floor" in the bmv manual. In the app it is the third item under "battery" which can be changed by the user. 50% is the default. In the 4.2.1 section of the manual it should be listed "03.", but it is not. I can't find it listed anywhere in my physical manual, or the downloadable manual. I assume it is the bottom half of the monitor's way to calculate "state of charge"? But a percentage of what? Battery voltage? Battery ah capacity? Thanks

biflip asked
seb71 commented ·

3 Answers

BMV-712 SOC not Accurate with Drop In Lithium (built in BMS)

After extensive testing, we found that the SOC is not accurate with Battleborn drop-in lithium batteries. We believe this is due to the fact the Battleborn's internal BMS is not allowing the BMV to take accurate readings.

For example, on a 100Ah battery - When the battery has half of it's capacity drained with 50Ah consumed, the SOC reads 0%. It will remain at 0% as more Amp hours are consumed and pulled from the battery. The SOC will register 1% when it is charged back to only 50Ah consumed, and will increase to 100% once it reaches 0Ah consumed.

Of course it should be a direct relationship for this example - Every Ah consumed should equal 1% in the SOC.

Is the lack of an accurate SOC a limitation of the BMV-712, since it was designed to work with Victron batteries that don't have an internal BMS?

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solarsean asked
lehrling answered ·

3 Answers

BMV-712 suddenly reports wrong high current

I have an RV trailer with single LiFePO4 battery, solar charger and AC input. BMV-712 works fine most of the time and reports sensible numbers. Occasionally though it enters some bad state when it reports approx +17A current (as if the battery is charging). Voltage readings are still good. The only way to get it back in good state is disconnect the power. Current reading fluctuates as the actual load changes. It seems the readings are shifted up ~17A or so.

I saw the same problem earlier when I had an AGM battery and a bit different wiring. All the cables are connected to large nuts of the shunt. The battery alone to one side, all consumers to the other.

I suspect it breaks down when there is a good charging current. Last time it did that when I left my RV with solar panels plugged in. (I use MPPT 75/15 controller.) Not sure how and when exactly it happened, I found it in 17A state when I returned. The other time I plugged the AC power, the battery started charging at about 30A, that gradually went down to 17A and I figured it is stuck. On the other hand, most of the time AC charging goes without a problem. Last time it even started charging at over 50A and BMV worked fine.

const asked
const commented ·

3 Answers

BMV-712 Smart on VE Smart Network

I have just installed a BMV-712 Smart to my solar system and added it to the network with my SmartSolar MPPT and Smart Battery Sense.

I did not purchase the optional temperature sensor for the BMV as I (and my dealer) believed that the BMV-712 would get temperature from the network, it does not.

The BMV allows for monitoring only one of either start battery, battery temperature or midpoint battery voltage.

Now that I have already wired and set my BMV to monitor battery midpoint, I can no longer have battery temperature, even with the extra optional sensor.

What information does the BMV see and use from the network? Is there any benefit having it connected to the network at all?

Victron – can this be changed in firmware?


lehrling asked
lehrling answered ·

3 Answers

Battery Monitor SOC Showing Empty Following Brief High Load

So, I've got a tiny little setup that has been going without issue for the past month. 100 Ah Battle Born, 150/35 SmartSolar MPPT, 712 Monitor, and an AIMS 2500W inverter.

I've been wanting to use the inverter to run my well pump to fill an indoor water tank. This takes only 7 or 8 minutes and even with my tiny battery bank and my less-than-efficient pump, the math shows this to be very much much within the limits of the system. I did a short, 3 minute test today to see what the actual load would look like and after doing so, my monitor is acting like I've completely drained my battery. The battery symbol in the lower right flashes and is hollowed out and the SOC percentage shows only a pair of dashes. The pump was averaging around 1300W according to the 712 for the 3 minutes it was turned on, which should only amount to a total draw of 65ish watts. What is more, the voltage shown by both the MPPT and the 712 after continues to show around 13.27V - clearly not an empty battery.

I've used the inverter on smaller loads before with no problem. I'm guessing that when the charge controller pops into float tomorrow the 712 will synchronize itself and all will be good, but I'd obviously like to not lose my monitoring every few days.

Is this a matter of improper settings on my end? A known glitch? Bad math?


figure-effects asked
lehrling answered ·

2 Answers

Voltage from BMV 712 incorrect - fuse size of temp sensor?

Hi all,


I read about incorrect voltage readings from the BMV712 when there is by mistake a 100mA fuse instead of an 1A fuse in the power cable.

I got an optional temperature sensor connected on my BMV and there is a 100mA fuse in the power cable. Does the fuse size have to be 1A also?


I didn't find a information about it.

mad asked
stefanie commented ·

2 Answers

Blue Smart Charger 12v (25a) with 36v Lithium Golf Cart Conversion (HELP NEEDED)

Hi All,


So this has got me stumped :( I have tried everything else that could possibly cause this issue but think it may be my setup with the charging. So here’s a summary:


I have a 36v Ezgo golf card which previously ran on 6 x 6v Trojan Lead Acid batteries. As a company we have recently got into the solar field so wanted to "experiment" with converting the cart to Lithium batteries as a side project. After quite a bit research I settled on 3 x 12v 108Ah Blue Nova Mobile batteries in series (https://bluenova.co.za/wp-content/uploads/2019/03/BN13V-108-1.4k.pdf).


To cut a long story short we did the conversion and it works brilliantly. Then came the issue of charging. One option would have been to use the 36v charger I already had for the cart. However, my concern there was that the "charging algorithm" on the charger was for lead acid. I did some research on Lithium chargers and found one expensive 36v option. I then got chatting to my Local Victron dealer and he suggested I use 3 x Blue Smart 12v (25A) chargers and install them in the cart permanently wired up to the batteries. What I liked about this idea was that I would be certain that each battery would be charged equally and would never get a battery imbalance (and it worked out cheaper) 12 So I went this route….


Fast forward 2 weeks – cart is going great, no issue and then suddenly battery 2 & 3 turn off (being battery 1 connected to main positive and battery 3 connected to main negative) 1 i.e. the internal battery BMS shuts off… I have gone through COUNTLESS different theories on what could be the cause (from parasitic drain, to wiring etc) but at the moment I’m wondering if the following could be happening (but need someone VERY knowledgeable people to prove or disprove).


So could the following be happening?:


1. Battery 2 and 3 discharge just ever so slightly more than battery 1 during use (as battery one is connected to main positive and batter 3 to main negative).

2. Then during the charging “somehow” the three chargers pick up on when the first battery is full (battery 1 in this case) and then all three chargers move to the next charging phase (say from bulk to absorption).

3. This leads to battery 2 & 3 losing out on just a little of a full charge each charge cycle.

4. In my case the cart is used daily and uses about 30 % in a day. After about 2 weeks maybe that “ever so slight” loss on every charge cycle drops the battery to a low level and the BMS turn off the battery to protect itself?

5. It is a “theory in progress” as the batteries where turning off every few days until I separated the 3 batteries, charged them, put them back in series and then for the past 2 weeks it has been perfect (until yesterday when they shut off again). So last night I separated the batteries again, charged them up and ill see how long they last.

6. So in summary, I suppose what I’m asking:

a. Can you use three of the Blue Smart 12v (25A) charges on 3 x 12v batteries connected in series (i.e. one charger connected to each battery)?

b. In such a setup would they in any way affect the operation of each other?


As a last note, I did install a BMV-712 Smart BUT because of the way the chargers are connected directly to the battery the “input” from the chargers cannot go through the shunt. So its set to reset to a full state of charge at a certain voltage (approx. 42v). This has helps me see what the parastitic drain is (approx. 0.01A) which I think is acceptable. This was verified with a clamp meter.


Any other suggestions would be appreciated 12


Thanks,


Richard


richsa asked
richsa commented ·

3 Answers

BMV712 correct settings for Lead carbon batteries

Can someone please help me with the correct settings for my BMV712
I have 24 x 600AH REX Lead Carbon Nevada batteries connected and 2 x 5000W inverters.

It was initially installed incorrectly and I have since rewired it, but now need to reset the settings so it works as it should.

Thank you so much
Caroline
P.S I have no idea about alarms etc either, complete solar noobie

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carolion asked
carolion commented ·

3 Answers

Smartshunt and Peukert coefficent?? Doubts...

Goodmorning everyone.

I bought victronenergy Smartshunt.

I must say that I am extremely satisfied with the accuracy of all the measurements.

Comparing the readings from TracerAn 3210 Epever and Smartshunt, they are surprisingly nearly identical, in both current and voltage.

They differ only by 0.02A and 0.02V. That is practically zero.


However, I am not convinced that the Peukert coefficient works.

In theory, by increasing the coefficient, the remaining runtime should shorten as the discharge current increases.

But it's the other way around:

for example, with a discharge current of 3 amperes, if I put coefficient 1.5 there is more time remaining, compared to coefficient 1.0.


The percentage of SOC also increases as the Peukert coefficient increases. I expected the opposite.


In my case, the statistics with default coefficient 1.25, seem too optimistic and less realistic than coefficient 1.0 or 1.1.

Can anyone clarify this for me?

francesco asked
francesco commented ·

3 Answers

Doubts Smartshunt cycle counting.

Good evening, I have been a very satisfied Smartshunt owner for about 2 weeks.


But I have some doubts.

1) I would prefer victronenergy to change the cycle count setting.

In fact, the software only counts a cycle when the battery drops below 65%. This is misleading.

I use a total of 190ah on the camper and the average discharge is 10/15%.

It may turn out that an Agm battery reaches the end of its life and the Smartshunt records only a few dozen cycles.

When in reality the battery has done the 1000/1200 cycles of 15/20% discharge.Cycles that are not counted by the Smartshunt.

Fortunately, the synchronization count is more realistic. Since a synchronization is counted every time the Soc goes below 90% and goes back to 100%.

So I associate the synchronizations with the number of cycles.

It is not possible that in two weeks of daily use it has only 2 cycles.

In reality I am 15 cycles of 20% of discharge... in fact I have about 15 synchronizations.

Otherwise my batteries will die with only 10/20 cycles recorded.

francesco asked
JohnC answered ·

2 Answers

Synchronize VE.Bus SOC with battery? Select on loss of communication source for genset

Synchronize VE.Bus SOC with battery

Has this item been rolled into dvcc? After some digging here it seems its been removed yet its still in the manual. The last mention of it in the changelog is in the v2.02 – 30 January 2017 Venus Os

Are you guys working on an update to the manual to remove redundant settings to avoid confusion?


loss of communication source for genset

I have a few systems I setup and support with auto start gensets, after a couple of weeks of bad weather one went into LVD during a sustained load at a low SOC. Voltage start timing settings were a bit too long to catch the voltage crash. LA batteries.

I had set start on loss of communication as a third fail safe to start the genset, and had the BMV as the source for genset SOC. However the genset didn't start as the BMV was still active yet the multi had shutdown. I had assumed that it would start on loss of comms to anything on the VE.bus. After rereading the manual, it's loss of communication to the SOC source.

Normally I disable the battery monitor in the multi to avoid the user accidentally changing the source.

I have now reenabled the monitor in the multi, which seems to be tracking the BMV and set the genset SOC source to the multi.

However Synchronize VE.Bus SOC with battery is completely missing so the only indication the SOC is being read by the BMV to the system is that its the same as the BMV.


Seems a rather complicated method, could we simply have this changed so we could select the loss of communication source?


This now raised another question, when performing remote configs through the portal the multi/quattro drops communications to the venus device for a moment. Will this cause a genset start?


alan asked
JohnC commented ·

1 Answer

Unable to measure voltage on starter battery

Not sure if I wired up my battery monitor wrong or my shunt is faulty. I want to measure the voltage of the starter battery. I have the postive cable on my starter battery and it's plugged into the B2 of the shunt. The negative of the starter battery is connected to my mppt then goes to my shunt on the load side. On my display it shows 0.03V (pretty much zero). I have checked the settings and it's set to starter battery. If I switch the B1 and B2 around my voltage changes and is roughly correct when I check it with a multi meter.

Is my wiring correct or have I wired something wrong or is my shunt faulty?

winston-hung asked
Wayne answered ·

1 Answer

BMV-712 resets to 100%

I have a Bmv-712 batter monitor that is resetting to 100% when the battery is not fully charged. Looked at the level around 8am and it was at 89% checked it 15 minutes later and it was at 100%. Nothing else was plugged up and I was checking to see what my solar panels were charging to determine if they needed clean. Now I am not sure what my battery is at to reset. Is it possible the BMV would reset itself?

chadwick-torp asked
the-boat-galley commented ·

2 Answers

Charging a 12V Lifepo4 battery. Who has the key to this mystical knowledge?

I have bought a lifepo4 12.8V 40Ah battery from an unknown but experienced manufacturer for a small project, that was not too expensive to wake the kraken and dragon of my spouse.

It came at 13,33V and looked very tame.

I charged it with a blue smart ip65 12/15 charger on lithium configuration and low current (4A) instead of 15A to wake it up softly.

The manufacturer prescribes a CCCV load profile with cut off voltages of 14,6v high to 10V low. But Victron thinks that 10V is too low. They told me to cut off at 12,5V. And load with 14,2V.

I think Victron uses a more conservative load profile. Maybe to protect the battery from unballanced cells in these high limits? Is that right? Or does that have another reason? Lifepo4 is lifepo4 right?

The first charging got to 14,2V for a little while, but then very quickly started ballancing at 13.5V. Is that normal?

So now the battery is 13,5V... Which is good I guess for storing the battery? When I look at a voltage chart of 12V Lifepo4, that is about 90%SOC? I have enough capacity to do what I want, so that's ok.

But I need to calibrate an Aili battery monitor (I know it might be rubbish but I want a little experiment). So when the battery is 100%, I have to tell the monitor by pushing a button that it's 100%SOC. But how do I know whether the battery is completely charged at 100%? On the voltage charts of lifepo4 I see that 13,5V is not 100%, but the smart charger brings the voltage automatically to 13.5V, and I don't want to start messing with the configurated values...

I also have a smart battery sense, a smart battery protect on load side, a battery protect on charge side, and an mppt 75/15 for a solar module when I install everything. Some are new, some were of a previous AGM project (that's why the chargers are 15A, instead of 10A which would be preferable for a 40Ah battery). But without a shunt, these victron appliances can't determine the SOC, so they can't help me either, although they all blink very willingly.

Any suggestions to educate me on this and protect my precious investment from my erratic ignorance, and help me to set this battery monitor please?

Would it calibrate itself when the battery reaches full capacity again? Even when the voltage drops again to 13,5 V?

maartenvt asked

0 Answers

BMV712 temperature sensor and status not working

I got a temperature sensor on my BMV712, but no matter what I try in settings, it shows nothing like it's not connected.

I got another one from the store to see if it maybe broken but that one gave the same result.

Other issue.....after a little while BMV712 shows load drops to 0% in a couple hours after charging, but the 4x 12V220Ah agm's are fully loaded.( New batteries)

Can it be a broken print on the shunt or is the BMV itself broken?

Everything else seems to be working fine...

Multiplus 12/3000/120, 360Wp, Mppt12/24-40

edwin-prasing asked
edwin-prasing commented ·

0 Answers

VE.Smart Network Support on Blue Smart Charger

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!

Christian Lindermann asked
maartenvt commented ·

9 Answers

BMV 700 SOC percantage does not match to the used Ah

Hello together,

i have identified a problem at my BMV 700 regarding the shown percentage from SOC (State of Charge)

My current SOC shows 93,1 % with consumed Ah from 34,6 Ah.

From my calculation, 34,6 consumed Ah should be already 15 % of discharge.


Whats wrong in your opinion?

I am a litte bit confused about the datas which are shown.

Unfortunatley i become less trust in the percantage of SOC.



First some basic data from my system:


Battery: 230ah

Technology: AGM



Settings:

Battery Capacity: 20 hour capacity as recomended in the manual

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Stauts:


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Best regards Julian




locke asked
locke commented ·

8 Answers

bluesolar monitor - change to bmv-712 bluetooth

Since my current (dealer installed) setup up has a bluesolar charge controller MPPT 150/35 which doesn't have bluetooth, I want to know if I can simply swap the monitor ONLY to a BMV-712 and will it ONLY require plugging it in to the current wires? ( bluesolar documentation is very poor and the bluetooth monitoring seems so much better)

Thanks

steve-mcrae asked
steve-mcrae answered ·

2 Answers

BMV 712 relay not activating when programming matches conditions

I've got a BMV 712 hooked to a Cyrix LI relay but the BMV 712 relay doesn't seem to be following the parameters to open it close the relay as expected.


The only thing that will cause the BMV to change the state of the relay is when I hit the invert relay function. I've tried having the invert relay switch on or off and it never follows the voltage or soc low/high settings configured. The relay stays constantly on or off depending on how I have the invert relay function set... everything else seems to be ignored.


Can anyone shed some light on what I'm missing here? I get absolutely no reaction to any voltage or soc charge low/high events. I've tried different relay modes, disabling the event and enabling it, nothing. Thanks



Set to 24 low and 28 high, charger mode and it looks like it is working because the relay is closed since I'm at 26.9v.

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But then I change the high voltage down to 25v and nothing happens. I would expect it to realize the voltage is high and open but it doesn't seem to care.

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The only time I've been able to change the state is if I turn the invert relay switch on/off... otherwise it never changes state.


Cory Wikel asked
Cory Wikel commented ·

4 Answers

BMV 712 fuse

My BMV712 has stopped working. I suspect the fuse may have gone. What rating is the fuse so I know what to replace it with?

Thanks very much,

Tom

t0mb0 asked
bruces answered ·

3 Answers

BMV 712 - no current or power

There is no current or power coming through on my BMV 712.
Does that mean the wiring is wrong?
Or has it been set up incorrectly?
Any help greatly appreciated, my installer is not around.

connected to 24 x REXC 600 Lead Carbon batteries.

carolion asked
carolion answered ·

9 Answers

total pv yield added to historical data

Hey,

I am witnessing some strange behavior in my historical data view every five to seven days.


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The advanced view - again - does show the correct production and consumption of those three days.

I have then exported kwh and log data for this timeframe.

December 23rd:

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December 31st:

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January 6th:

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For some reason the total pv yield of the inverter since installing has been added several times to the kwh export, thus altering total production and consumption in the historical data.

Inverter is a Fronius Symo 10.0-3. There were no other errors or anomalies visible in the log.


Thanks for any idea and help!

Chris

chriss83 asked

0 Answers

Connection lost between BM712 and Venus (on Raspberry Pi 3b+)

Hi there,

After a successful installation of Venus OS on a Raspberry Pi 3b+, I managed to configure the Remote Console, link it to VRM, and view the live data streamed. All worked OK...for a while: after more or less a couple of hours, I noticed that I was not getting updated data from the Battery Monitor. It seems that the issue is the connection between the gateway and the BM - see screenshot below:

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Rebooting solved the issue...for a while. After another hour I had the same issue again. See below (three reboots):

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In my current set-up, I only have a BMV712smart connected to the VRM. The Pi is connected to the router via network wire. The BM is of course plugged in to the Pi via USB.

Below please find more screenshots of the Remote Control.

Thanks for your help and guidance, I did a research but couldn't find any thread on this specific topic.


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flavio-dim asked
flavio-dim edited ·

1 Answer

VE.Net Battery Controller still functions correctly?

Hello,


Designing a new system with a MultiPlus II 5kVA GX. I have two MPPTs and need a shunt connected for battery monitoring as the multiplus doesn't seem to do a very good job of displaying the correct SOC when using "dumb" PowerPlus lithium batteries..


Will the VE.Net Battery Controller function the same as a VE.Direct BMV (smart shunt)? I understand it's a depricated protocol.


The Lynx Shunt is too expensive and physically not practical for this system design.


Regards


Isaac

Isaac Shannos asked

0 Answers

BMV-700 is showing fuller capacity than the voltage suggests (possibly wrong as much as %30) I need to know how to sync it properly.

My BMV-700 is showing fuller capacity than the voltage suggests (possibly wrong as much as %30)

I need to know how to sync it properly.


My system is a 24v solar

Victron Easy solar 24/1600 inverter

2 x Rolls Batteries S12-290AGM 12V 260Ah (C20)

Victron Battery Monitor BMV-700


System has been in place for a year, I have noticed the BMV SOC is wrong over the past 2 months.


My sync parameters are as follows :

1.Battery capacity – 260 Ah

2.Charged Voltage – 29 V

3.Tail current – 4%

4.Charged detection time -10 minutes

5.Peukert exponent -1.25 (default)

6.charge exfficiancy factor – 95%-(default)

6. current threshold – 0.1 A (default)


question 1 ?are any the parameters needs changing ?


Possibly i need to sync the BMV again, my understanding was the unite sync itself by bringing it to %100 charge twice a month.

My question 2- can I sync it manually(using the buttons) any time or is the solar system need to be at a particular stage for syncing?


merav asked
merav commented ·

1 Answer

Can BVM 712 Smart Shut Off All Battery Power?

I have a 712 smart, ACR 7611 and Zamp 30Amp Controller, with 330 w solar panels. When I turn on two vent fans on high in about 3 mins all DC power is lost...BVM shows SOC 99.8 and 12.6v when system shuts down.

Can the 712 shut off all DC power?


Thanks...

phillip-buttolph asked
randy-putnam answered ·

1 Answer

BVM 712 SMART Relay - What does "remote" do? Not in documentation

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.

mduncan asked
karelholubicka commented ·

3 Answers

VRM+BMV712 - No Batt Temp

I have recently hooked up my BMV712/MPPT Solar to VRM portal via VenusOS - its really great and loving it so far.

I have battery temp being fed into the network by Smart Battery temp sensors. And this works as I can see Batt Temp on the solar? (or was it the BMV?)

Anyway - I was wondering if I am doing something wrong as despite the battery temp being on the network, it is not passed through to VRM.

Thanks

Al


bigal asked
mtnbrit answered ·

2 Answers

BMV SoC and Battery Cell status not alligning?

2 x 150ah Victron SmartLithium batteries:

Battery 1

  • Cell 1: 3.05V
  • Cell 2: 3.04V
  • Cell 3: 3.05V
  • Cell 4: 3.06V

Battery 2

  • Cell 1: 3.08V
  • Cell 2: 3.09V
  • Cell 3: 3.00V
  • Cell 4: 2.97V

System is saying 71% state of charge. And the A-SL11 under voltage alarm is saying "battery full discharged, cell voltage below the allow to discharge cell voltage set in the app.

The manual says:

4.8.2. Cell under voltage pre-alarm thresholdWhen the cell voltage drops below this threshold, the pre-alarm signal is sent to the BMS. The purpose of the pre-alarm is to warnthe user that the system is about to shut down due to undervoltage. For more details see chapter: “System design”.The default value is 3.10 V and the range is 2.80 V to 3.15 V.

Is it correct that my system is at 71% SoC? To use the system below 70% I can just change this Cell voltage disconnect feature down to 2.80V? And are the Cell 3 and 4 readings anything to worry about?

lemonjelly asked
stefanie commented ·

2 Answers

BMV 712 Relais on high SOC

Hi! is it possible to Switch the Relais on a High SOC? between 95 and 100% ? i cant do that by voltage, because i run Lifepo Batterys.

finalshare asked
simen commented ·

1 Answer

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