SOC Image

SOC

ESS SOC LIMIT

Hi,


I try to set my Minimum SOC to 70% but the active SOC limit won't allow me to go lower than 80% on ESS

Any recommendations to set it lower?


[image]

hdp asked
Matthias Lange - DE answered ·

2 Answers

multiplus SoC not syncing to 100% (mains backup system)

Hello,

I have a system with:

1 x MultiPlus 24/3000/70-50 firmware 476 (but problem predates this firmware too)

4 x Trojan SAGM 06 375

for mains backup.

----------------

Edit 2020-11-24

Having clarified a few things since first opening this post I'm listing here the key points as I see them:

The system is not triggering a bulk/abs cycle after anything except a very deep discharge. I.e. it returns straight to float after small to medium discharges.

This means that over time, with several small/medium discharges the SoC indication gradually drops off, when really it should return to 100% once mains returns after such discharges.

I have been told that, by design, the bulk/abs cycle is triggered when the battery voltage drops below 26.2V (2.6V, for 24V systems, below the set absorption voltage of 28.8V). This is happening here, yet the bulk/abs cycle is not activating.

----------------

Original post:

The SoC indicated by the system will not sync to full for long periods of time, which results in the system always showing well less than 100% even when in float. Please see the VRM screenshot below.

I raised this issue somewhere on Victron community/disqus a good while back, but can't find it anymore! We never got a resolution, but I recall it was discussed that the reason was:

i) the battery voltage doesn't drop low enough under the brief discharges/small loads to trigger a full bulk/abs cycle (the SoC does reset to 100% on the rare occasions this does happen).

ii) the repeated absorption feature (which is set at every 7 days on this system) does not trigger a SoC reset on completion

I'd be very grateful for any ideas on how to resolve this, especially now as the system is using the new "shut-down on SOC" feature, which means the batteries will be cut off sooner than necessary due to starting with an already low SoC.

Many thanks

[image]

Edit 2020-11-02

I've added vrm screenshot to compare charts for the same mains failure event for this system and another very similar system (only differences I can think of are 48Vnom/375Ah vs 24Vnom/375Ah and CCGX vs venus GX). This system goes straight back to float, other system goes through bulk/abs cycle.

[image]

Edit 2020-11-24

Just adding another screenshot here as we've had some interesting events over the last three days. Of note is how a bulk/abs cycle was triggered by the full discharge to 40%. However, the most recent discharge to 80% didn't trigger a bulk/abs cycle. I'm wondering if perhaps somehow this system has the bulk/abs cycle voltage level trigger of a 48V system even though it is a 24V system?

[image]

colin asked
colin commented ·

2 Answers

BMV 712 SOC reads "--", Inverter reads "lo", No BMV history

I'm converting a Ford Transit 250 into a camper and just finished setting up my electric system last week.


Components:

BMV 712 Smart Battery Monitor

MPPT 100v 30A Solar Charge Controller

(3) 100Ah LiFePO4 Battle Born batteries

Giandel 2200W Pure Sine Wave Inverter

Sterling 60A B2B Charger

Progressive Dynamics 60A 12v LiFEPO4 Battery Converter/Charger


I've been reading forums and doing a lot of research and can't figure out why the Battery Monitor state of charge just shows 2 dashes (--), and there's no history (Deepest discharge - 0Ah, Discharged Energy 0.0kWh, etc.). It's been this way for about a week now.


Also, when I turn my inverter on, it beeps continuously and says "Lo", indicating low voltage protection. Yet my 12v system runs and works fine (water pump, lights, fan, etc.). But when I turn the inverter on to use my GFCI outlets, they don't work. And again, I can't tell what my SOC is.


I've gone through the battery settings in the Victron app and changed everything to the recommended specs (see attachment).


Could anyone please point me in the right direction?


Thank you!

[image]

[image]

joycarlaina asked
joycarlaina commented ·

1 Answer

Active SoC stuck at 80 %

Hi! I have a question regarding the functioning of the parameter 'Active SoC limit' that can be found in the ESS. While in mode 'Optimized (with BatteryLife)' I started playing with the different parameters to test the installation, and in particular with the parameter 'Minimum SoC (unless grid fails)'. At first, both 'Minimum SoC (unless grid fails)' and 'Active SoC limit' had the same value, but after increasing the value of 'Minimum SoC (unless grid fails)' up to 100 %, the 'Active SoC limit' became stuck at 80 %.

I would like to know what does this parameter 'Active SoC limit' really mean and what's the functioning behind, so I can have a better understanding of it once I change the value of 'Minimum SoC (unless grid fails)'. I have already read the ESS Manual but it is not very clear to me yet.

I would like to add that my installation works mainly disconnected from the grid except in a few occasions that it is connected for short periods of time. I don't know if that has anything to do with the system recognizing this and, thus, trying to set a high value according to this characteristic.

Thanks!

inigodu asked
Hendrik Coetzee edited ·

2 Answers

Batteries apparently losing charge on light load

This is a new installation set up using default settings on smartsolar and multiplus II.

When first connected, Colour Control GX showed battery charge at 85% if memory serves. Over the course of three weeks, battery SOC indication has dropped to 30%. Apart from two very brief higher load scenarios (vacuum cleaner for 5 minutes and fridge freezer for 2 hours) the only load has been the base load of about 5-7W (according to colour control).

Colour control is recording voltage of 55+ Volts on the 48V AGM 230Ah battery bank (confirmed by meter on the battery terminals), so the smartsolar will not do an absorption charge for very long (1 hour on default) before reverting to float.

As I write this, it is 11:32am, bright sunshine, and VRM is recording a 9W AC load, batteries idle 11W, SOC 29%, 55.4V and current 0.2A, and PV charging at 50W.

What am I missing?

20871pault asked
20871pault answered ·

3 Answers

What happens when BMV712 sees charging beyond 100% SOC?

I have a BMV712 + MPPT 75/15 in my new RV, and I've been collecting data through various conditions. After a lot of analysis, I'm convinced Johannes's video from earlier this year is providing the 'best' settings for my solar scenario, where I'm setting Charged Voltage = 14.2V (14.4V absorption minus 0.2V) and tail current around 5%. The downside is that we will synchronize when we're at approximately 95% actual SOC, and if we charge exclusively via shore power (which has a lower 13.8V absorption voltage), we will never synchronize. Setting lower tail current is not an option because we don't always stay in absorption mode long enough to see this lower current, and we don't want to set a lower charged voltage + lower tail current in float mode because clouds could result in a false synchronization.

So on to my question: when we synchronize, whether it's manually or automatically, we often will do so at a level slightly below the actual 100% SOC. What happens if we continue charging (regardless of whether it's in absorption or float) beyond this point? Specifically, will the BMV start counting down from 100% SOC after that additional charge is discharged? Or will it ignore that additional charge and just start counting down as soon as it sees any net discharge on the battery?


Here's an example:

- 200Ah battery, charged to 95% (190Ah), and synchronization event happens, setting the BMV to 100% SOC.

- Since we're not 'truly' at 100% (but rather 95%), an additional 10Ah of charge continues to be applied before true float/maintenance state reached.

- After that point, we apply a load that consumes a net 5Ah power off the battery.


What's the BMV going to indicate?

- Will it internally calculate that we're at 100% + 5Ah capacity (effectively, 102.5%) and keep displaying 100% SOC until we've discharged more than the 10Ah "extra" we added post-sync?

- Or will it ignore that extra 10Ah of additional charge and just show that we're now at 100% - 5Ah = 97.5% SOC?


In simplified terms, when does the BMV start counting down from 100%, and how does the BMV handle additional charge beyond what it thinks is 100% SOC?


My guess is that anything above assumed 100% SOC is ignored/clipped, but the engineer in me wishes there was a way to better reflect 'true' SOC rather than jumping to 100% SOC when we're in reality only around 95%. The quest for accuracy :)


Thanks!

Tom

Tomasz Czernecki asked
rslifkin commented ·

1 Answer

SmartShunt SOC synchronization with SmartSolar MPPT

I know! This question have been asked before, and I think I have read every answer twice...and I am still not able to get my system to behave as I want.

System consists of 2x24V 100Ah LiFoPo4 batteries wired in parallel, SmartShunt, SmartSolar Charger MPPT 100/50, MultiPlus-II 24/3000/70-32, Cerbo GX and some other bits that are not important here.

I tried to configure the SmartShunt as per. the manual:

Charge Voltage: 26,7 ( SmartSolar float - 0,3v)

Tail Current: 2%

Charged detection time: 3 minutes

But this resulted in SOC resetting to 100% every morning when the SmartSolar started charging.


Based on the description of what the parameters does, and the graphs I could pull from vrm, I then tried to set the charge voltage to 28V and lowered the detection time to 2 min. But now the SOC does not reset even when the SmartSolar is done charging.

Below are graphs of such a scenario:

[image]

I do not understand why the SOC was not reset to 100% when the voltage was >28V and amperage was close to zero for many minutes?

Settings for the SmartShunt are:

[image]


Settings for the SmartSolar are:

[image]


I hope you guys can help here, because I don't understand it :)

bomadsen asked

0 Answers

How to set SOC charging target other than 100%?

My system has 2 Smart Li 200Ah batteries, Multiplus 3000/120, 2 MPPTs 100/30, connected via BatteryProtect, Alternator connected to AGM, and via Cyrix Li to Li batteries. Setup includes BMV-712 Smart and Venus GX.

I want to be able to charge the batteries to say 60% or 80% only while on shore power, knowing that I will have plenty of sun for the rest of the day.

How can I set an SOC target for the Multiplus, or better via Venus GX? I don't want to change the absorption/float voltages.

kupo asked
hackett answered ·

7 Answers

Inaccurate readings?

[image]

Trying to understand and get a descent battery reading since I installed this BMV-712.

I added a RPi 3b+ with VenosOS for monitoring.

Attached is the latest readings from this week.

The numbers don't make sense to me.

I have two golf cart batteries (230Ah each) in series, so 12v with a useable 230 amps (Right?)

So if I have used 82 amps of the 230 as stated by the monitor shouldn't that be 64%, how does the monitor calculate 78%?

Is there a setting to mitigate this error? A setting I've missed?

Also, the (mostly) at rest voltage is 12.17 volts? Is this not considered a battery at roughly 50% charge?

(There are parasitic loads in the trailer, fridge, CO2 Dect. ect that I cannot remove)

I was hoping that this 712BMV help me determine the state of my battery, but I'm as confused as ever!

I just want to get the most out of the batteries without damaging them early.

Attached is the last week of use. battery started from full. Zero Cal was done with everything disconnected with the exception of the BMV itself.

mogal asked
mogal answered ·

2 Answers

How can I set custom SOC in my Multiplus C 12/1600/70 without using VE config?

I have lithium batteries in my boat and do not want to charge them to more than 85% SOC normally except when I plan longer trips and want to top them off to 100%. Is it someway I can change that through either VRM or via Cerbo and Touch 50 without using VE Config? Would be a nice feature to have for managing lithium banks. Custom SOC and then shut off the charger when SOC is reached. Second feature would be to have the auxiliary charger on for maintaining current to the AGM starter battery bank.

trulsla asked
Alexandra edited ·

1 Answer

How to see SOC on Easy Solar 24/3000/70-50 MPPT Colour Control Inverter Charger system

I have just had a Victron EasySolar 24/3000/70-50 MPPT 150/70 Color Control Inverter Charger System installed in an off grid setting, trying to make sense of the manual [which says for a multiplus so poss wrong manual? or is the EasySolar a MultiPlus?] though there is also a Smart Solar charge controller manual, [lists lots of various mppt] but can't really make any sense of this either. Basically would really love to be able to work out how to see the batterries SOC [state of charge] which is how I used to guage my old system, Firstly on the Color controller GX, Then I think I have connect to it online but can't fathom that out either, not sure if I some sort of wifi dongle {where would I plug it in as the color controller is attached to the inverter/charger] or plug in an ethernet cable? I have been trying to research it from the Victron site, but so many pages link to other pages that don't seem to function & I am getting more confused.

We used to have a 12 volt system & this one is now 24 volt so also quick question, before I could gauge my batteries by the dc voltage [Not wanting it to go below 11.5] now as this is a 24 volt system on the color controller in the bottom left hand battery icon, its states around 25.1 v -1.4A [fluctuating] is the 25.1 v the battery voltage as its on a 24 volt system [so 2 x 12 would be 24] so 25.1 is Ok & I guess if it goes down to 23v this would be equivilant on 11.5 on a 12 volt system.

It seems such a shame that there doesn't seem to be any guide on the victron site or in the manuals what this wonderful colour controller images mean! for non tech savvy folks like me

Thanks in advance

lucylite asked
Alexandra answered ·

1 Answer

EasySolar-II SOC keeps falling and never rises?

Recently commissioned a EasySolar-II 3kva 48v system running PowerPlus Energy 4kwh ECO module. Setup battery monitor on VEconfigure, programmed mppt as per powerplus recommendation and all looking good. About 5 days later system shutdown on low SOC cut-out, went to site and batteries full and on float but SOC showing 15% so it had slowly gone down each day after i left but was in fact being charged fully each day. Where have i gone wrong??

mark-dreyer asked
on2itmaclennan answered ·

3 Answers

State of charge

Hello ,

I have MultiPlus Compact 12/1600/70-16 + Smart Solar MPPT 100/50 all in one.

Im monitoring system on GX display.

Everything is connected and it works good, but i have problem setting state of charge?

Is it possible to have state of charge with this configuration, or i need to install shunt?


[image]

T

nevercarry asked
nevercarry answered ·

2 Answers

Does the Relay Assistant in a MultiPlus Compact (aka Phoenix 12/2000) continue to work after low SOC shutdown?

Hi there,

I would like to be able to turn a MultiPlus Compact (Phoenix 12/2000) off when reaching a defined SoC. This part is easy. I would however also like to continue to use the programmable relay in the same MultiPlus to turn off DC loads via a Battery Protect when the SOC reaches a (lower) threshold. In other words, what I have in mind is turning off AC loads at say 25% SoC and turn DC loads off (relay driving a Battery Protect) at 15% SoC.

Is that possible?

Jan

jbakuwel asked
jbakuwel commented ·

0 Answers

SOC DIFFERENCE

I have a cerbo and a Lynx shunt on my BMS. The data says in a 24 hour period I have 1.3 kwh of solar and 1.1kwh of consumption so more power in than out, my SOC at the start is 77% and at the end 73%. How can the SOC reduce if the consumption is less than the solar generated ?

paul-clingan asked
Stefanie answered ·

1 Answer

SOC and Tail Settings

I added two photos showing the SOC went to 100% very quickly and was thinking I might need to change the settings for the tail percent?

2x SLR125 125ah agm batteries

Battery size = 250ah

Charged Voltage = 13.1v (thinking of changing this to 13.2)

Charge Time = 3m

Change Tail = 4% (not sure about this one)

[image]

[image]

[image]

burnttech asked
burnttech commented ·

1 Answer

BMV SOC just does not add up (or subtract) what is wrong here?

Setup: I have a BMV 700 On my boat with 300Ah (@C20) batteries, a pretty constant load current of 1A and an MPPT recharging the batteries when there is enough Sun.

The BMV SOC and Ah consumed values disagree by approximately 50% which is worrying because if the trend is across the full capacity the battery could be empty when the SOC says 50%.

I dont think it is anything to do with the setup (wiring to shunt etc.) as all I am looking at is the BMV data (see graph below) the BMV is reading the current (in/out) and making the calculations on this data so it is just not in agreement with itself. I would be happy to understand where I have gone wrong and learn from my mistakes, here is my reasoning.

I have read the article here.

https://community.victronenergy.com/questions/58699/bmv-700-soc-percantage-does-not-match-to-the-used.html

But I started a new thread as this is new data and I think it might be proof that something is not right (or I dont understand). In that article it says it might be the Peukert exponent but it is set to the Victron default 1.25, charging efficiency default 95%, battery capacity set to 270AH which is the C20 capacity less 10% all as set my my Victron installer. So if I am following Victron recommendations what more can I do?

Considering:

1) The load at 1A is so low that Peukert should not have any effect (which is about inefficiency when drawing high currents).

2) The problem can't be charging efficiency because the SOC is too high even when no charging has happened.

3) it cant be the wrong current reading because the BMV is using the current reading as its only input value for all the calculations. (it could be wrong but it should not be inconsistent)

4) it can't be the battery capacity setting that throw the readings out by 50% and anyway I have only entered the one capacity value so the BMV must base all its calculations on the capacity I have set (270 Ah).

5) Finally it should not be the discharge floor setting (15%) as setting a discharge floor should cause the SOC to be lowered for a given AH consumed value. Anyway according to the documentation discharge floor only impacts the time remaining.

BMV is Firmware version 3.11 - it was installed by an authorised Victron installer.

OBSERVATIONS

At the end of charging yesterday afternoon the BMV reset to 100% SOC and 0Ah used. Then 14 hours later this morning before the MPPT started up the values were.

  • SOC 98%, (actually looking via the VRM it gives the SOC at 97.6%)
  • Consumed 12.9 Ah,
  • Current -0.9A

The current was constant at between 0.9 and 1 A overnight, so I feel I can trust the consumed Ah. But the SOC at 97.6% suggests that 2.4% has been consumed and 2.4% of 270 is 6.5 Ah almost exactly half of the displayed consumed Ah.

The other suggestion in the article above is that it is rounding errors so I looked back through my data, as I took screen shots of the BMV display on my smart phone at intervals over the last 2 months.

Here is what I see:

The orange line is the % consumed calculated based on consumed AH (according to the BMV), the blue line is the corresponding line for 100%-SOC% (I.e. how much the BMV SOC says has been consumed). The lines are amazingly straight and as you can see the SOC is consistently saying that the amount consumed is half of what the consumed AH says.

[image]

IF anyone want to check here are my battery setting in the BMV.

[image]

My ultimate worry is that others who use the boat from time to time may rely on the SOC display and run the battery down without realising.

laurenceh asked
laurenceh commented ·

1 Answer

Soc 100% at absorbtion beginning

Hi folks!

On my system, SOC reaches 100% about 1 hour before the end of Bulk while full sun at 10:00. I thought that Bulk could only fill 80% of the battery capacity and that absorption was designed to fill in the remaining 20% and reach fuil SOC. I set BMV with the C20 Ah capacité Where am I wrong?

Lionel SEYDOUX asked
michelg edited ·

5 Answers

Battery SOC 100% but still charging?

Hello


In a solar system i have 2 packs of both 4 exide 330A gel batteries. Together this forms 2 sets of 24 volt batteries.

This setup is charged by solar panels connected to a MPPT 150-60 and a Multiplus compact 12-1600 is connected as well.

The system is monitored by a BMV 700 and this is connected to a color control gx.

Settings for the BMV are:

- Ah 660

- charged voltage 28,4 volt


My question:

Why the BMV tells the battery is 100 percent charged while the voltage is around 26,70-26,85 and still charging around 8 amps??


Shouldnt voltage readout be like around 28 volts and charging amps around at max 0,5 or so?


ThAnks in advance!


Best regards, Piet



piet-hein-van-asselen asked
piet-hein-van-asselen answered ·

4 Answers

Feature request: Dynamic Grid-Setpoint in ESS, based on top SOC.

Currently the Grid-Setpoint in ESS is a static number (in watts) that controls how much system power is allowed from grid, with the remaining load being served by incoming solar and/or battery capacity, down to a tolerable SOC. While that works great in the assumption of keeping batteries @100%, every day, it’s not so good for long-term health and maintenance of lithium batteries, in a (stable) grid-tied system.

I would like to suggest an upper limit to the SOC (other than default 100%), at which point the ESS would dynamically shift the load more/less (by changing Grid Setpoint) to charge the batteries when they’re below the high mark, and otherwise running the load off of solar or battery capacity, down to the existing minimum SOC (as normal)... or similar type of functionality.

Currently, I’m constantly changing the Grid Setpoint down, to serve the system loads from the incoming solar preferentially, as much as possible. Then resetting it up again at night, to keep the batteries above a reasonable SOC. While workable, it is way more manual than it needs to be.
I believe adding a simple top SOC to the algorithm that controls when to shift to using solar would greatly simplify and automate this process.

geomz asked
Alexandra commented ·

0 Answers

State of Charge never gets reset - BMV700 with MPPT 75/15 and 110W Solar panel

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.




Dominic asked
Dominic commented ·

3 Answers

Grid SetPoint and SoC

Hey guys,

Very Quick quesiton. If I set grid setpoint as a -ve to discharge battery when spot price is high, can I rely on the SoC setting to stop discharging when the batteries get too low?

What one takes precidence?

Mike

Mike Casey asked
Mike Casey commented ·

1 Answer

Simulateur de SOC raspberry

Bonjour à tous

Afin de tester le bon paramétrage d'une installation PV, j'imaginais utiliser un "simulateur de SOC" . Quelqu'un a t il déjà fait cela ? à l'aide d'un raspberry par ex ?

Merci d'avance

denis-esf asked

0 Answers

2xBlue smart IP22 charger 12/30 (3) parallel on LiFePo4 questions

Usecase: REC ABMS connected to 12x 272Ah cells (Lishen), 3 parallel and 4 series (12V). Charging with 2x Blue Smart IP22 30A, Smart Solar 75/15 and TS800C-50.

The manual of the Blue smart IP22 is very limited with respect to its behavior of the "Lion" setting. First it doesn't feel right they call it "Lion" while LiFePo4 is a total different chemistry, but as they put LiFePo4 between () I assume this mode is for LiFePo4. Anyone that can confirm this?

Can someone explain how the charger behaves in the "Lion" mode?

I want to parallel two of these chargers. Is this going to cause any problems? Do I need to use the "Lion" mode or is it better to use the power-supply mode when putting in parallel?

From what I understood (e.g. https://marinehowto.com/lifepo4-batteries-on-boats/) LiFePo4 is very sensitive to overcharging. Even with low voltages (~13,5V) the battery can be killed when current is applied after 100% SoC is reached (very low internal R). So it is very important to stop charging when the current does reach a certain threshold (ideally SoC based), or to control this externally using a BMS. Anyone that can comment on this?

joep asked

0 Answers

SOC calculation worse with latest Multiplus firmware

First, let me say that I understand that, for my setup, the Multiplus's calculation of SOC will inherently be incorrect.

(Right now I have my battery bank being charged by both my Mutliplus and occasionally by my SmartSolar MPPT. So the Multiplus cannot see the current being fed to the batteries by the MPPT.)

Still, the SOC calculation was better with the firmware immediately prior to v481 that is now.

And I think it can be "hacked" to do better, as below.

Consider the following two screen shots, taken at two parts of the day.

[image]

This first shows the battery voltage is 26.56V and the SOC is 57%.

Now, as the day progressed, with solar charging, the battery voltage has increased to 26.82V. But the SOC has decreased to 31%!

[image]

I know that this incorrect SOC calculation is because the Multiplus is (apparently) looking at current only, and has seen 7 to 8 Amps leaving the battery all day, but is not seeing current coming in from my MPPT.

But as I said above, the previous firmware of the Multiplus handled this situation better.

Might I suggest a software hack, that when the battery voltage increases, the SOC calculation be prevented from displaying lower? That would solve the false low SOC reading in this case.

pmikep asked
pmikep commented ·

3 Answers

How to get Plyontech batteries to 100% SOC

Hello

My system is 2 x US3000 batteries, 1 x Multiplus II 5kw with a 1kw ongrid connected to the AC IN (waiting on stock of a BlueSolar) and a Cebro but I have an issue that the Cebro gives me a high battery voltage alarm with 91% 92% SOC and the charging stops... I can clear the alarm and sometimes it will go back to charging the batteries with 10 amps but that only lasts a minute ( if at all) so for now I cannot get near 100% charge. Any ideas thanks .

davidrkennedy asked
seb71 commented ·

2 Answers

BMV and discharge floor impact on SOC reading

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

siletzspey asked
Stefanie answered ·

2 Answers

SOC vs Voltage

High in the southern french Alps, my house is powered by 2kWp on the roof, 30kWh OPZS lead batts and a 3kVA generator all manages by a full Victron system. The last 3 months the sun has been scarce and erratic but I kept my Multiplus 24/5000/230 running to keep a fridge and a congelator running as it is good to have something under your teeth after a 2 hours climbing in the snow. Max watts 150 when both run, but as the room temperature is about -4°C it should be for very short periods with a daily load under 1 kWh/day .

Q1: But on VRM, the voltage stays very low: Yesterday afternoon 24.77 for a 100% SOC and this morning 24.41V for SOC=99.3. These values are not consistent and I fear my settings are wrong though set as required (Ah at C20 for BMV). Or my bats are completely out of order.

When I manage to get there, probably April, I shall test my settings and SOC with electrolite density, but I may have to switch to LiFePo bats a little later.

Q2: Another idea: I tried to have some information about REDOX batteries which could store enough to regulate my power the whole year round (100kWh should do). No answer yet.

Q3: A third idea: I may have to change my panels so I look for wood looking things which could easily cover the whole roof, all spare place being filled with somme look alike materiel or wood. Any idea?

The last two questions are a bit far away from sea-faring devices, But our community is universal isn'tit?

More info as needed

Lionel

Lionel SEYDOUX asked
Lionel SEYDOUX answered ·

2 Answers

Smartshunt inaccurate SOC

Hi Guys, Thanks for the great community and support, I have always found this forum to be extremely helpful.

I seem to have an issue with the Smartshunt State of charge in a recent installation.


I have 8x 90AH 12v Yuasa batteries in parallel totalling 720AH.

I set the minimum discharge floor to 60% as my usage is minimal and I would be surprised if I reach that below 80%.


Now the Smartshunt indicate total consumed AH to be -48.1AH and the SOC to be 97%. I think this is inaccurate


Now if I do my math ( I could be ignoring many factors)

according to the set discharge floor of 60% I have 40% usable.

40% of 720AH = 288AH

Expected SOC = 100% -( 48.1/288)x100) = 83.2%

and not 97%

I am confused. can you please help :) below are screeshots and battery specs.


Many thanks



[image]

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vanlifer007 asked
vanlifer007 answered ·

3 Answers

MPPT 100/30 Charge Control Battery Charge Display Issue

My battery state of charge display shows a charge drop when a load is draining the batteries..... but when voltage is being applied to the batteries it does show as charging up until I unplug the cord from the shunt and plug back in? Eg.....shows a drop of in charge but doesn’t show an increase in state of charge until the wire from the display to the shunt is unplugged and plugged back in. It has on a couple of occasions shown such a low state of charge that it shuts down the electrical even though the batteries were charged.

cdhackney asked

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