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DVCC

3-Phase MultiPlus II ESS System with an additional MultiPlus II for battery charging

Dear Victron Fellows,

I have the following use case for two almost identical installations:

On the already existing 3-Phase ESS installation using MultiPlus II Devices, the battery should be charged in case of a grid failure and in time of insufficient PV power.

The installation already has the following devices:

  • 3-Phase ESS installation using 3 MultiPlus II 48/3000 operating in parallel to the public grid (230V)
  • 3-Phase Fronius AC PV converter connected at the critical loads AC Output of the Multis and controlled by frequency shifting (MG50)
  • CCGX
  • BYD B-Box 10.0 connected by VE.CAN to the CCGX
  • MPPT Solar Charger connected by VE.direct to the CCGX

A single phase 5kVA 230V Diesel inverter is available. It should be used to provide the power for the charger.

Is it possible to charge the battery using an additional MultiPlus II connected to the CCGX?

Can the Multi be connected to the CCGX and does it receive the relevant battery information BYD BMS information (DVCC)?

According to the following question it should be possible. And that is what I would expect and I think is the reason of DVCC.

Asking my dealer to verify the answer he told me that it is not be possible to connect the additional Multi to the existing CCGX, because the additional multi would need its own controller and needs to operate independent from the ESS system.

He suggested to connect the Multi by the relays (LINK). This would not be an preferred option for me because I would expect the charging process to be more optimal if it is controlled by the batteries BMS.

If the additional Multi can not be connected to the CCGX, would it be possible to add another Venus device and connect the CAN Bus to this device for retrieving the BMS information?

Best regards,

Martin

martin-m asked
martin-m commented ·

3 Answers

Cerbo GX, DVCC and combined charging from Multi, MPPTs and alternator. How measured?

Hello all.


I have some curly questions on using a Cerbo GX and Distributed Voltage and Current Control (DVCC) to manage the system described below.


The yacht installation I’m preparing will have four Victron 12.8V 300Ah Smart LiFePO4 batteries, arranged in parallel. Their overall voltage will be sensed by a SmartShunt, connected to the Cerbo by VE.Direct. The batteries’ 3 Pole Balance Temperature & Voltage (BTV) cables will be daisy-chained to a Smart BMS CL 12-100. This BMS will control a Smart Battery-Protect 220 via its Load Disconnect terminal. The BMS will also control a Cyrix-Li-Charge 120 via its Charge Disconnect terminal. Three Smart MPPT 100/50 solar charge controllers will send current from 1200W of solar panels to the batteries through the Cyrix. The MPPTs will connect to the Cerbo by VE.Direct-to-USB adapters, into a USB hub and then to one of the Cerbo’s USB ports. Another job the BMS will do is regulate battery charging from a 115A alternator.


The system will include a MultiPlus 12/3000/120-50 inverter/charger, connected to the Cerbo by VE.Bus. Current from the MultiPlus will not be routed through either the Smart Battery Protect 220 or the Cyrix-Li-Charge 120, to avoid damaging those with flow in both directions.


I’ve read Victron’s explanations of DVCC, along with relevant discussions here in the Community. I’m satisfied it will work. What I think will happen (and not happen) is:


- the Cerbo will take the battery voltage sensed by the shunt and assess this in terms of what it was told the batteries are, during setup;


- it will look up its program library of how these batteries like to be treated and will instruct the MPPTs and the MultiPlus how they should serve up amps for charging, or draw on them for inverting;


- when the Cerbo assesses that the battery voltage reported by the shunt is getting low, it will tell the MultiPlus to stop inverting;


- the Cerbo will not be able to stop the DC loads from drawing upon the batteries, as it has no data connection to the BMS or the battery-protect. These two will use their load-disconnect linkage to cut the loads when one of the batteries says ‘Stop!’;


- if something goes wrong and the Cerbo doesn’t succeed in stopping the MPPTs from charging, the BMS will step in when the batteries ask it to and stop the charging via its charge-disconnect link to the Cyrix;


- however, if something goes wrong and the Cerbo doesn’t succeed in stopping the MultiPlus from charging, there’s nothing in the system or the setup to cut it off. I assume that the MultiPlus will not stop itself from charging, given it’s been told to be dumb and work under DVCC rules. Perhaps I could add a Cerbo controlled relay as a back-up, to switch off the MultiPlus if it goes feral?


Please set me straight if any of the above is off-beam.


*****


Some aspects I’m less clear on are:


- will the shunt report the overall charging current from the MPPTs, the MultiPlus and the alternator, such that the Cerbo might instruct the MultiPlus and the MPPTs to ease-off or stop?


- if the batteries are full, does the BMS have the ability to throttle the current from the alternator? Checking … . Yes, it does.


- and last but not least …


… the Cerbo GX has a second pair of CAN-bus ports, called BMS.Can. Little is written about these, other than how they can be used to hook up other-brand CAN-bus BMS equipped batteries or BMSs. So how good would it be to have Victron lithium batteries that can talk directly to a Cerbo over CAN-bus? :-D Has Victron said these are on the way, or ruled them out for some reason?

valden asked
bathnm commented ·

3 Answers

Pylontech SCS Shared Current Sense

The Pylontech documentation is silent on the SCS parameter:

[image]

Default is on. Must it be on? I will update it based on this answer.

@Daniël Boekel (Victron Energy Staff)

warwick asked
warwick commented ·

1 Answer

Discharge Current Limit in Multiplus-ii with Pylontech and Cerbo

Hi, I have a question around the behaviour of the Multiplus-ii when connected to Cerbo GX with DVCC on under the control of Pylontech US3000.

The US3000 manual has the following current limits:
Recommend Charge/Discharge Current (A) 37
Max. Charge/Discharge Current (A) 74
Peak Charge/Discharge Current (A) 100A@15sec

The Cerbo DVCC Discharge Current Limit is set to 37A since plugging in the Pylontech cable to the Cerbo. What will happen when the load on the Multiplus causes DC current to exceed 37A? Will it just shut down or alarm, or something else?

I really need it to allow the Multiplus to operate within the specification of the battery, to allow for short-term high load scenarios as this is an entirely off-grid install with solar and backup generator.

Thanks, Chris.

chrisb13 asked
chrisb13 answered ·

2 Answers

DVCC to limit total charge current?

I have a parallel multiplus system, with a BMV712, and CERBO GX connected to a FLA battery bank on my boat.

I am interested in limiting charge current when the engine alternator is producing as well as the generator as to not exceed the charge current acceptance rate of my batteries.

A method that we have discussed is using a AUX input on the master multiplus to trigger a reduction in the output capability of the multiplus units. This aux contact would be tied to a “main engine running” signal.

I am certain that this method would work, but there might be a better way.


Could I turn on DVCC on the CERBO GX and have it limit the charge current by using the value supplied by the BMV712?

That would be the best method in that it would be dynamic.


Please let me know.


Thanks!!!




blskevin asked
Matthias Lange - DE commented ·

1 Answer

Connecting smart bms to other victron items

I have just purchased LifePo4 victron smart batteries and a smart bms. Am I right in thinking that I use a non inverting remote cable to connect the bms to my cerbo gx and use dvcc mode to control the mppt.
also where does an Orion tr smart 12/12-30 go in this situation???

My thought was the Orion output goes to the ve+ post of the battery and the remote (h) connected to the bms, likewise the mppt output connects here also and is controlled via dvcc parameters.

I have a smart battery protect that I am putting between the ve+ post and my loads (bus bar) but see that it is one way hence the questions ref the chargers.

Hope this makes sense and thanks in advance for any constructive advice given.

graham78 asked
graham78 commented ·

1 Answer

DVCC Firmware insufficient warning on System overview

This error keeps showing up and then clearing, it has done so at least 10 times in the last couple weeks. All firmware is up to date according to VRM online checking.

Cerbo GX

3 Quattros

BMV 712

3 BlueSolar Charger MPPT 150/85

2 Skylla-IP44 24V/30A (currently turned off)

It's getting pretty annoying to get an email every time this happens and then clears, I have looked through every post concerning this and see no solutions, anybody have an answer to this?

Thanks, Ron

ur12vman asked
ur12vman answered ·

3 Answers

Multiplus doesn't see Cerbo GX Temp Sensor

I have a Multiplus (Easyplus) 12/1600 along with a Cerbo GX and other stuff.

Because I want to use the BMS Assistant on the MP, I had to use the Temperature Sensor input for the control signal (the MP 12/1600 has no other Aux input). This works well and I can control the Charging feature exactly as I want with this assistant.

I was fine with doing that as I could use a Temp Sensor that was connected to the Cerbo GX instead and enable DVCC and the STS feature. That seems to work fine for the SmartSolar MPPT and that picks up the temperature from the sensor correctly, but the MP shows the temp reading as either "NaN C" or "20 C".
I have two temp sensors on the GX and I have tried setting the Sensor in the STS selection to either one of them and it makes no difference to the MP - although the MPPT sees the change (and neither are 20 C either).

Any ideas why the MP is not picking up the Temp Sensor data from the Cerbo GX?

wildebus asked
wildebus edited ·

3 Answers

Strange DVCC issue, need to disable and re-enable daily to get full MPPT harvest.

Hi guys, wondering if anybody can point me in the right direction on a little MPPT VE.Direct problem.

I have a small Multiplus 24/5000 grid-tied system running great with BMV-700, Venus GX and off-brand DC coupled PV charger with 200Ah of Li-Ion. I've recently added another PV string on an MPPT 100/50 Rev2. Everything has latest firmware as of this post.

The MPPT is working great, except that every day its output is down by a few hundred watts. Heres the wierd part - It comes good when I disable DVCC then imediately re-enable it again. It remains at full output until the next day. Here's a video showing this:


In this video you can observe the output is down from what it should be. After disabling DVCC, the MPPT settles on a much higher output, with most going to the battery (huh? already 100% soc) and a little extra going to the grid. When DVCC is then re-enabled, the MPPT continues to produce full power, and the excess goes correctly to the grid. That is, until the next day.


The utility connection is a 10A circuit, so export is limited by the Multiplus to 2400W. When there is excess solar and the grid circuit hits 10A export, DVCC correctly backs off the MPPT as intended, so the battery is not overcharged past 100% SOC and the 10A grid circuit limit is observed - great.

My suspicion is that there is a bug somewhere in this code which is somehow causing the MPPT to stay backed off even when it should be instructed to return to full power output. When this condition is in effect, the charge voltage target in the MPPT is observed at 27.3V (while battery remains at 27.1V, as observed in the MPPT's menu on the venus GX). The mppt *should* be going flat out, but somehow remains backed off.


No battery current limits are ever being hit, the battery temp is mid 20C at all times, wire gauges are all correctly sized and nothing is getting hot.


Any ideas?

victrowok asked
victrowok answered ·

1 Answer

DVCC system in a yacht - configuring and switching on

Hello Everyone.

Could I please have your advice on configuring and switching on a newly installed DVCC system in a yacht? Questions at the bottom. First, a system description. The devices involved are:

- three 12.8V Smart lithium batteries, in parallel as the house battery bank
- Smart BMS CL 12-100, to keep the diesel engine’s alternator safe from overheating
- Smart Battery Protect 220 for load disconnect
- Smart Battery Protect 100 for charge disconnect of MPPT output (might change to a 220)
- Smart Shunt
- Cerbo GX and GX Touch 50 display
- MultiPlus 12/3000/120 - 50
- three 100/50 MPPTs with three x 400W solar panels

There are also two battery chargers connected to the positive bus-bar, being:

- an Orion-Tr 12/12-30 battery to battery charger, for charging the engine start battery, if needed
- a Sterling 12-24 charger for charging the 24V battery bank for the bowthruster

Data connections between the devices are:

- VE.Direct cable between the Smart Shunt and the Cerbo GX
- VE.Bus between the MultiPlus and the Cerbo GX
- VE.Direct-to-USB between the MPPTs and the Cerbo GX

And of course there are:

- load disconnect cable from the Smart BMS CL 12-100 to the Smart Battery Protect 220
- charge disconnect cable from the Smart BMS CL 12-100 to the Smart Battery Protect 100

I’ve read the DVCC information in the Color Control GX Manual. I’d happily read more information if it was available. :-)

How do the following configuration steps look to you?

- I need to activate DVCC in the Cerbo GX. Easy.
- I’m thinking I will activate ‘Limit charge current’ at first, to keep charging calm, at 50 amps max
- Shared Voltage Sense (SVS) comes on by default when DVCC is enabled. From Section 4.4.2 of the Manual, I gather the Smart Shunt will be the source of the voltage measurement, rather than the MultiPlus. This makes sense, so I think I’ll leave SVS on.
- Shared Temperature Sense is a problem. The system doesn’t have a temperature input at present. The batteries in the bilge are likely to be colder than the distant MultiPlus, a possible temperature source. I think I will turn STS off, until I can connect a sensor directly to the Cerbo. Which sensor?
- Shared Current Sense (SCS). Section 4.4.4 of the Manual is difficult to understand, but I get the impression I should turn SCS on, so the MPPTs can be configured to use the Smart Shunt’s current measurements.

Could I please have your thoughts on this approach? I will of course be working with the installer, however, he is not a Victron expert.

Thank you.

valden asked
bathnm edited ·

3 Answers

BMV-712, CCGX, Multi Plus & DVCC enabled, two separate battery banks

In this configuration (RV) with a main battery and a truck battery both connected and charged by one Multi Plus. BMV-712 monitors the main battery voltage and the truck battery voltage. DVCC enabled on the CCGX.. With all connected, it works as advertised. However if for some reason the main battery is disconnected from the camper DC system (BMS action), the Multi Plus gets confused seeing the main battery (now disconnected) voltage and trying to power/charge the rest of the system along with the truck battery. This of course causes the Multi to create significant voltage swings.

Is there a way of telling the BMV-712 to switch from sharing the main voltage to sharing the truck voltage instead as it is the one getting charged?

Any other suggestions?

The BMS could in effect via a relay swap the voltages sensed by the BMV-712. That appears to me the only alternative. I would rather not do that.

roamer105 asked
roamer105 edited ·

1 Answer

multiplus rebulk voltage threshold

Hello,


I couldn't find anywhere the re-bulk voltage offset threshold that the algorithm of a Multi (MP-II, or Multigrid, whatever) in an ESS system with DVCC enabled with unmanaged batteries (nickel-iron batteries in our example) is applied ? For example, we have a bank of 24V NIFE with 31.5VCC for absorption, with the following parameters :


[image]


The bulk-abs-float cycle starts all over again once the voltage of the batteries drop below the float voltage, or below a pre-determined voltage threshold, or minus a certain % of the float voltage, andfor example for how long ? 1 min ?


Couldn't find the info on the Victron documentation (it is clear for MPPT charging algorithms though, but not for internal Multi's DVCC algorithms). We've set up those settings depicted above in order to be able to restart a full charging cycle with a 2h absorption cycle, if the voltage of the array drops below a certain limit (2x times a day max = 0.5 days absorption interval). It would be helpful to manually override the threshold, just like you can do when you have non controlled MPPTs charger (in which you can specify the re-bulk voltage). In any case, knowing the default value would help us in having more prediction over the conditions that trigger a new charging cycle.

Based on our experience and .csv log, it seems like the Multi restart a full charging cycle once the battery voltage drops at the nominal voltage (~ < 25VCC). Can anyone confirm this ?

Thanks in advance for your help !





perma-batteries asked
perma-batteries commented ·

1 Answer

REC-BMS, GX, Multiplus DVCC Firmware insufficient alarm warning

Hi and thanks for reading this.

I have a REC-BMS (Victron version) connected to a Raspberry PI3 with CAN-HAT running 2.60 which has worked very fine for some weeks. Tonight I connected a Multiplus 12/1600/70 via MK3-USB cable to the PI. I also have a BMV-712 connected via a VE.DIRECT cable using the same shunt as the REC-BMS.

All devices appear on VRM Remote Console and look fine. The battery charged to 14.2V just fine and current quickly tailed away to zero-Amps. After a short period of use, an Automatic Monitoring 'DVCC Firmware insufficient alarm: Warning' appeared.

My Multiplus is an 1906 model running firmware 209; could this too old for REC-BMS control? I see a Victron helpful stating 19xx model is supported. Also have two-signal lithium assistant running if that makes any difference.

Some VRM screenshots attached somewhere below.

Many thanks.


[image]

[image]

[image]

[image]

sv-gabrielle asked
Daniël Boekel (Victron Energy Staff) commented ·

2 Answers

DVCC, BMS and Ve.Bus interaction

Hi,

I have been working on a couple of project involving MG batteries with BMS, Quattro and CCGX controller. I have read the DVCC section of the CCGX manual and if it greatly help understand the basis of DVCC some details are left out and I need to reassure our customers.

Some system also includes Blue Solar Ve.Can controller(150/85), Skylla and /or Skylla-i

System are set per recommended settings in the DVCC section of the manual.

The Manual mentions that when DVCC is ON the Ve.Bus device and MPPT system are "controlled by the BMS". and they follow the CVL, CCL and DCL sent by the BMS.

Q1) The BMS does not send the data to the device directly since they are not on the same network. The CCGX appear to be redirecting the references. Are each device directly controlling the charge voltage based on the CVL or is the CCGX adjusting the Current limit to each device to meet the CVL?

Q2) In a case of the BMS controlled system, is there a need to set Absorbtion/Float voltage or are those numbers ignored by the Device?

The Solar charger strictly indicate external control and if the BMS communication is lost they seem to Stop charging. So it seems that the setting are ignored. Are they?

The Case of the VeBus device is not that obvious. External control state does not exist. It seems that the LED are either Bulk when some charging is happening and Absorbtion when the charging stops or oscillates. Never seems to get to float which is disconcerting for some of our client.

[image]

Is this the intended behavior?

Is the absorption voltages set in the charger profile totally ignored or used as "Limits"?

Should the BMS communication stop how will the system react? Will the Quattro stop charging or inverting?


jmarc asked
Daniël Boekel (Victron Energy Staff) answered ·

1 Answer

Orion TR Smart woes. Not impressed.

Hello,

I have three different Victron DC systems and had plans to add the Orion TR Smart to two of them. I purchased a 12v 30a non-isolated Orion TR for my RV and to bluntly put it.. I'm not impressed.

This device has no ve.direct connector, what is the logic behind this decision? If I've invested the money to control every aspect of my Victron system through Venus, why would this device be headless? There also seems no way to add it into the bluetooth VE networking protocol.

I have come to rely heavily on DVCC for my dynamic charging needs, so the fact that this device can only be controlled through bluetooth with an extremely limited set of configuration options is frustrating.

The bluetooth radio in this device is abysmal. I can control every other Victron Smart product meters away from them, whereas this Orion TR doesn't even broadcast outside of the vehicle it's in. I have also seen similar complains in the ratings sections of a retailer and on this forum.

Has anyone used the external relay control features of their multiplus or possibly bmv-7xx to provide at least some type of logic-based control to their dc-dc charger?

I feel like this device was rushed to market. I am struggling to see the value in the Orion TR, I am considering returning this item. Does anyone have any insight if there are firmware improvements scheduled for this product or if I'm missing something here?


teejmiller asked
alnavasa answered ·

4 Answers

How to program equalization with Venus GX, MPPTs and DVCC on

Hi,


My question: Is there a way to manually equalize or automate equalizing while using DVCC?


My problem: When DVCC is on it seems impossible to trigger equalizing. I have tried via the GX console or directly on the charger via VictronConnect. Without luck. When I switch off DVCC I can trigger equalizing with VictronConnect over Bluetooth on the charger.


My setup:


Island setup. No connection to the grid.


- Battery: 24 V, 900ah lead acid

- Panels: 18 275W. Configured as 2 arrays (east, west). Each connected to a charge controller

- Inverter: Multiplus 24/5000/120-100

- Charge controller: 2x SmartSolar Charger MPPT 150/70. Connected vi VE.Direct

- Venus GX


DVCC settings:

- DVCC on

- Limit charge current 100A

- SVS on

- STS on


Regards,

Daniel




oliveoil asked
oliveoil edited ·

0 Answers

How to determine if DVCC is a good option for configuration

As the title says, I’m trying to figure out if I should be using DVCC or not. My setup is expansive, but not complicated, and it’s a marine application.

10kw generator

1x Quattro 12/5000/220 utilizing the VE.BUS BMS

2x Battery Protect

8x Victron MPPT’s hosting 3kw of solar,

5x Victron Smart Lithium 300AH.

B700 Battery Monitor

1x D400 Wind Generator


I’m looking for some advice, I inherited this system when I purchased the boat, but went from a dual Quattro in parallel to a single Quattro. So I’ve had to configure everything from scratch, with very little knowledge.

I’ve read up on ESS - and it appears I should NOT be using the ESS assistants because of the lack of Anti Islanding.

I’ve attempted to read on the DVCC system, but I’m not sure if it would be helpful.

I’d love to hear from someone that’s using a similar setup, and understand what configuration, assistants they are using, and why.

Bryan asked
ejrossouw edited ·

1 Answer

MPPT not charging during Multiplus absorption (DVCC)

Should DVCC allow the MPPT to charge when sun is available, even when the Multiplus starts a charge due to low SOC early on a sunny day?

I've found the Multi will still be in absorption and the MPPT will go to float, but decides not to bother with any output, even though it could.

If i turn the MPPT charge off and on (in Victron Connect) it will try to charge for a few seconds but quickly cycle through Bulk-Absorption to float and give no output.. Only when the Multi goes to float does the MPPT start charging.

I'm using DVCC, + Ignore AC, both MPPT absorption and float voltages are higher than the Multi's

Could it be overheating? Today was hot and the batteries showed a peak of 37 Deg C, or maybe an incorrect setting, I.e. reduce the Ignore AC charge to end after bulk, but that's not ideal until we have more solar?

Or a symptom of the MPPT adaptive charge, either way i thought DVCC should tell them both what to do, as the Multi decided to use the AC In mains to charge when there was enough sun to cover the end of the absorption phase :( ..?

Thanks

VRM link:

https://vrm.victronenergy.com/installation/62545/share/c76c4bf6


[image]

Al asked
JohnC commented ·

3 Answers

PV input power fluxes/dips in a pattern, is this normal ?

Given you are looking at 3 or 6 hour window of VRM. There is almost a perfect pattern of 'dips'

Is this normal ? See picture.


* I am in CO, Fire smoke is constant and has been for weeks.

* I have DVCC enabled, is this causing this ?

Cerbo GX

24/3000/70

MPPT 250/100

BMV-712

x6 100Ah 12v Battleborn in 3PS2 24V 300Ah

x8 400W panels 2PS4 ~ 190v/20A

[image]

[image]



pmano asked
pmano edited ·

2 Answers

SmartSolar MPPT 100/30 output fluctuation since update to fw1.49 using VictronConnect v5.21beta5.

I just updated a SmartSolar MPPT 100/30 to firmware 1.49 using VictronConnect v5.21beta5 (iOS TestPilot says beta 5 but settings shows beta 4), the solar harvest starts fluctuating and also the DC voltage starts to show some disruption. The output will slowly increase and then suddenly drop to 0 after which it starts up again slowly. It would continue this cycle until the sun is down.

After the update, VenusGX showed a notification that there was an unsupported DVCC firmware so I updated the connected Phoenix MultiPlus 800 to FW 474. I also updated the ESS assistant. I have restarted every single component in the system, disabled DVCC to no avail. Eventually I removed the load and disabled feeding back into the grid to safeguard the battery because this was the only thing I could do to stop the DC voltage fluctuation.

I also have a BMV700 in the system which is already running latest firmware.

I did do a factory reset for the SmartSolar MPPT to no avail. Could something have gone wrong during the firmware update? It halted for a few second during the update process and then started over. Is there a possibility of downgrading the MPPT to a slightly older Firmware just to check?

This system had a perfect was working perfectly before, there were also no clouds in the sky that could explain the behavior.


[image]


wrietveld asked
misullivan commented ·

3 Answers

Quattro battery charging voltages not observed with BYD battery when DVCC is enabled?

Hello

All firmware for 3 Phase 5 KVA quattro , Venus and charge controllers , fronius are latest with BYD 10 KWH pro batteries - system VRM ID is TapetaMain

While troubleshooting my random switch offs I observed the following behaviour

The Battery sits steady at 55.5V and occasionally jumps to 55.6/55.7 volts at fill SOC Despite the Quattro settings of 55.0 as float and 55.2 as absorb

Both DVCC is on and the solar charge controllers show Remote control active .

See screenshots

has something changed in DVCC alhorithm ? I suspect my issues are linked to BYD switchiing off in Overvolatge when large load swings happend such washing machine or dryer happen .


[image]

[image]


[image]

[image]


Anil Ghatikar asked
Daniël Boekel (Victron Energy Staff) commented ·

2 Answers

CAN bus battery - controlling external loads and charge sources?

When using CAN bus batteries such as BYD and Pylontech with inbuilt BMS, is there a mechanism to have an effective "charge enable" and "load enable" signal from a Venus device to shut down external charge sources and loads before imminent battery shut down. Use Relay 1 and Relay 2.

An example might be a vessel where non-essential loads could be shut down before battery shutdown. Or disabling an alternator charge source.

Might this be part of DVCC? The system would, of course, have a BMV device to know net battery current.

Gary Pacey asked
Gary Pacey edited ·

1 Answer

Can the SmartShunt get (STS) info from a Multi using DVCC?

Does the SmartShunt's SOC calculation need it's own independent temperature sense lead, or can it produce the same accurate SOC using the MultiPlus temperature lead with (STS) enabled?

I have Multi 24/3000/70, CCGX, 2 x MPPT 100/30, 530Ah PZS FLA batteries. Shorepwer, On a barge, with no other DC loads. (This is separate to navigation / starter battery system)

I currently use a Smartguage for accurate SOC and set the relay output to shutdown the Multi with assistants (only in case of a low SOC emergency). I'm about to install the two MPPT's, and have been adjusting the Multi's SOC parameters in VEConfig to mirror the Smartguage as closely as possible, but it's never that good.

If i get a SmartShunt I can use Ignore AC more accurately with its SOC, but if possible i'd like to use the midpoint monitoring function, rather than use another temperature probe on the SmartShunt, unless the SmartShunt's own temperature probe is needed for the most accurate SOC calcs?


Thanks Al

Al asked
JohnC commented ·

2 Answers

CCGX compatible BMS Device for 6s Li-ion batteries ?

Hi,

Id like to change my Lead-acid 24 Volta battery to a 24Volt Li-ion Tesla batterie module.

Each module consists of six "cells" of nominal 3.6vdc consisting of 74 Panasonic NCA 18650 cylindrical battery cells of approximately 3.2 Ah capacity in parallel. This 6S74P configuration then features a nominal voltage of 21.6v at 233 Ampere-hours for 5032 Watt-hour capacity.

Expl.: https://hsrmotors.com/products/battery_modules

So the Question, do you know of any BMS system that is compatible to the CCGX.

Maybe even with DVCC functionality, or just logging and monitoring.

Greets and thanks

Gernot

notger asked
gyrogypsy edited ·

3 Answers

DVCC doesn't seems to work?

Hello again.

I'm a bit confused with DVCC function.

I've charged my batteries to 100% today, which triggered BMS to stop further charge, but Multi is not stopping, DVCC setting is enabled, BMS is sending all limits to VenusGX correctly, but it looks like Multi is just ignoring it. My DVCC settings are as below:

[image]

Battery is 100% charged, BMS set the charge current limit to 0.0A, but multi is still pushing nearly 1A into the batteries:

[image]

My system is VenuxGX (with ESS Assistant) + Multiplus II 48V/3000VA + AC coupled PV + Liion batteries with Batrium BMS (connected to VenusGX via CANBus)

I've also noticed that the same thing is happening when BMS is forcing limited charging mode (battery nearly full, CCL set to 0.5A), the Multi also is not limiting power to the set current:

[image]


Is that normal??? Am I missing something? Shouldn't Multi limit the power to the set value or I just misunderstood this function?!

mysik asked
Daniël Boekel (Victron Energy Staff) answered ·

2 Answers

Charge limit voltage (CVL) precision

I have a question about Charge Voltage Limit (CVL) when using BMS connected via CAN bus. In my system (VenusGX and Multiplus II) I'm using BMS connected via VE.Can (Batrium BMS). I would like to set Charge Voltage Limit (CVL) to 56.75V, but it looks like precision is fix to just one decimal place, so I need to set it to 56.7V or 56.8V. Is there a way to have 2 decimal places (e.g. 56.75V). All settings in VE Configuration tool have precision to 2 decimal places, why CVL (and CCL as well) is different???

Kind Regards

mysik asked
Daniël Boekel (Victron Energy Staff) commented ·

1 Answer

Ignore AC and DVCC

I have recently installed solar panels on my motoryacht. I am now looking for the most economical use of the solar panels, also in order to reduce the cost of shore power. The electrical system has mainly Victron components, except the panels and battery: Quattro 8000/200, Venus GX, MPPT 100/30, 720 Ah tubular plate batteries and 2 x LG Neon R 370 Wp panels, latest firmwares.

I have studied all the manuals and looked for answers on the community site. Although I see similar setups, I still do not have the ultimate answer on how to use the panels the most economical, either by using Ignore AC, DVCC, lower float voltage or a combination of these.

I fully understand how Ignore AC in VEConfigure works and have now set it up according to below screenshot:

[image]

I have been to the yacht today and have tested it with several loads. When using heavy load, the Quattro will deliver the power instead of drawing it from the battery, so it does not unnecessarily drain too much, which would take forever for the panels to charge back into the battery. There is a certain amount of equipment that draws about average 200 W, so in a day I will loose 4.8 kW. On sunny days the panels will charge with about 4.8-5.1 kW. So on cloudy days and near winter time the batteries will slowly deplete and when voltage reaches 23.5 V, the Quattro will kick in and charge (with max 100 A) up to when bulk is finished (85 % SOC). I might change that in wintertime to when absorption is finished, as the batteries need to be fully charged every once in a while. So far so good.

The manual of the MPPT states that the DVCC function will result in the MPPT being an active controller in the system. "For systems with lead batteries, DVCC offers features such as a
configurable system wide charge current limit, where the GX device actively limits the
inverter/charger in case the solar chargers are already charging at full power". I have tried the DVCC feature (without Ignore AC) with a setting of 100 A for max charging and shared voltage, current and temperature sense.
I have observed the behaviour of MPPT and Quattro for a long time and my impression is that the MPPT does not always do what it should. I can see the Quattro charging with high amps and the panels with relatively low. When I switch off the shore power, the panels immediately jump to a much higher charge, so the panels are under DVCC not used with maximum capacity. I would also expect that when batteries are full and loads are low, while panels can produce more than the load, that the Quattro might stop charging all together.

An expert advised to lower the float voltage of the Quattro with 1 V, After lowering that setting to 26.6 V, I saw this morning at around 08.00 hrs that the Quattro stopped charging. Not completely sure why?

I have gathered my thoughts and I think I have to options: 1) use Ignore AC and 2) use DVCC. With option 1, it will deplete the battery more and I think the panels are used most economical, but I need to make sure the batteries are getting a full charge every once in a while. With option 2, the batteries are kept a full charge (100 %)., but I have the impression the panels are not used to the max and the Quattro will only stop charging when the voltage of the batteries is higher than the 26.6 V. Which brings me to the question do I also need to lower the absorption voltage in order for the Quattro to stop charging when in absorption fase in order to get the max charge out of the panels? I find lowering these setting in contradiction to the DVCC manual: "Limit charge current. This is a user-configurable maximum charge current setting. It works across the whole system. MPPT Solar Chargers are automatically prioritized over the mains/generator".

By the way: I use the AC out 2 of the Quattro for heavy users, with the intention that when I loose shore power (while sailing [do you actually sail, drive or operate a motor yacht?]), it automatically switches of the heavy consumers and I will not unnecessarily deplete the batteries. With Ignore AC while still in the harbour, I loose the heavy consumers as the Quattro needs AC on either AC In 1 (generator) or AC In 2 (shore power). I probably have to rewire the heavy consumers to AC In 1.

My questions:

1) Why does the Quattro stop charging when lowering float voltage when panels are charging?

2) Do I need to lower the float voltage in order for the Quattro to stop charging while enabled DVCC?

3) Why is DVCC not using maximum available charge from the solar panels?

4) Do I also need to lower the absorption voltage while DVCC enabled so the Quattro stops charging in absorption fase to maximum use the charge of the panels

5) Can I, or should I, use DVCC in combination with Ignore AC?

Any comment, suggestions, answers are welcome.

I have also published about the installation of the electrical system and the solar panels on my weblog (in Dutch, but has Google translate button): www.xanthiona.com .

jurjenhoekstra asked
jurjenhoekstra commented ·

1 Answer

Can MultiPlus Compact 12/1600/70 firmware be updated through VE.Connect?

Hello everyone. I have a MultiPlus Compact 12/1600/70-16 on firmware version 154. Is this firmware out-of-date? Can this Multi's firmware be updated using VE.Connect, or do I need to use the (deprecated, dangerous(??)) VEFlash method?


Reason for wanting to update:

In addition to the Multi, the system has a BMV-702, CCGX, and 2x MPPT 100/50. The MPPTs charge a 12 volt ReLion lithium-ion battery bank from two separate solar PV arrays.

I would like to tell the MPPTs that the battery voltage is what the BMV-702 measures, and not what each MPPT senses at its "battery" output terminals.

This is because in bulk charging there is a discrepancy of as much as 0.7 V between MPPT and battery voltages, depending on charging current. Under float conditions, the discrepancy tends slowly towards 0.1 V. The voltage drop from the MPPT output terminals to the battery's terminals is presumably due to the cabling, fuses, and isolator switches, none of which can be changed.

I want the MPPT to receive battery voltage data from the BMV-702 (or maybe the Multi) to solve this problem.

I read here that I can do this with the CCGX using DVCC and SVS. However, when I tried this I got an error message saying that there is a firmware incompatibility issue. Since all firmware in the CCGX, the BMV, and MPPTs is up-to-date I conclude it must be an issue with the Multiplus' firmware.

Any help greatly appreciated!

glasses asked
glasses edited ·

1 Answer

BMW-702: High voltage alarms after enabling DVCC

Hi,

I have a 5KW Multi with 5KW of AC coupled solar (oversized arrays, PV inverters rate limited as per the 1:1 rule) as well as a MPPT which on ideal days adds another 1KW of solar power, all connected to a 600Ah 48V Lead Carbon battery bank. I recently enabled DVCC with SVS and STS and a current limit. The BMV-702 now reports high voltages: 57.8V, which indeed is a bit too high for my liking. The Multi is set to: absorp: 55.0V, float: 53.70V, the MPPT 250/60 is set to absorp: 55.20V, float 53.90V.

Often I see that the MPPT 250/60 has completely derated itself, while the Multi is still pumping ~1KW into batteries that are full. I would expect to see the Multi derate itself first (due to the lower voltages programmed).

I have two questions:

1. What could cause a high voltage situation of almost 3V above the programmed absorp voltages? The only explanation I can come up with is that it's caused by as high load disconnecting while the batteries are full. If this is the case, would this be considered an issue? Note: I have only seen this happening after enabling DVCC and my theory doesn't seem to be supported by the graphs:

[image]


2. Why is the Multi not derating before the MPPT is derating?

When the batteries are full, I prefer to derate the large AC coupled arrays first, and leave it to the MPPT to keep the batteries floating. High loads will of course cause the Multi and thus AC coupled PV inverters to rate up again and once those high loads are disconnected, to derate again. When the batteries are full, this happens fairly quickly.

regards,
Jan

jbakuwel asked

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