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Multiplus/48/3000 connects to Generator but doesn't charge. DVCC or tail current issue?

Hi All,

I'm running an off-grid system using MultiplusII/48/3000 with a Cerebo GX, MPPT/250/100 VE.Can rev2, SmartShunt 500A all connected with VE.Can. My battery setup is 20x 250A 12v Gel batteries in 48v with 3 battery balancers.

On the Multiplus AC input we have a 7.5Kw generator that we've configured to start when GX relay is turned on. We want to use the generator on cloudy days top up the batteries while briefly running our critical load.


When we start the generator and the Multi accepts the input, we see the system taking over 1000W from the gen to supply load and help charge the batteries alongside the MPPT250/100 as we expect. However, after less than 2 minutes, the load on the generator starts to drop in a very controlled fashion. It appears that either Multi or another device is limiting the generator input for charging, even when the MPPT is clearly still in bulk and the batteries need charging. This makes us very nervous about when bad weather will come and we'll be reliant on the generator charging the batteries.


We have not enabled DVCC yet for this install as we're not entirely confident about its impacts with our setup and running these Gel batteries. We also have issues with the Smartshunt's tail current settings not being able to set the % value below 0.5%. Given we're running over 1000Ah storage capacity, a tail current value of 0.5% is still 50A! We'd need either an Amp value or 0.05% to get to a more normal 5-7A tail current setting. I believe this results in our batteries always showing 100% as soon as the MPPT's start charging in the mornings.

We suspect it may be the tail current setting with battery SOC always being at 100%, but we are unsure this is why the Multi is not using the generator for proper sustained charging along with the MPPT. Perhaps because we're not using DVCC and this will help with global control of all the devices working together?

Attached some pictures showing setup and generator on but not charging. When MPPT is on, it give charge to battery. When MPPT is off, generator still doesnt charge.

Gen with MPPT.jpg
Gen without mppt.jpg
Smartshunt settings.jpg
Multiplus settings 2.png
Multiplus settings 3.png
Multiplus settings 4.png
Multiplus settings 5.png
Multiplus settings 6.png
physical setup.jpg

kmr asked
kmr commented ·

1 Answer

Quattro refuses generator when charging with more than 1250W?

Setup: Quattro-II 48/5000/70-50/50 + 3 Pylontech US3000C + Hyundai HY8500LEK (one phase)

Dear community,

we are currently in a no-grid situation, where I need to charge my three Pylontech US3000C with a 8500W Hyundai generator HY8500LEK (Manual and specification: https://cdn.hornbach.de/data/shop/D04/001/780/492/386/204/10573553_Doc_01_DE_20220708111753.pdf)

Charging works, but only when DVCC "maximum charge current" is set to 25A (at ~50V: 1250W)

As I understand, with three US3000C, I should be able to charge with 3x25A = 75A. But when I set the maximum charge current to 30A or higher (on Cerbo GX), charging only works intermittently - 15 second charging, charging breaks off, inverting starts, then a while later, it tries again, same thing...

How to analyze this situation? The generator should support a higher charging rate. Our AC loads are only ~500W, so with 25A/50V charging, the total load to the max 8500W (one phase!) generator is only 1600-1800W.

Is it because the generators AC out is not clean enough for the Quattro II, when running at higher loads? I can provide statistics, if you tell me what is needed.

I am aware of the Victron Generator FAQ, but as we are currently in an emergency situation, I would prefer not to do any firmware changes, which could result in a complete shutdown. No ESS is set up.

Thank you







tobyfw asked
Paul B answered ·

1 Answer

Pylontech UP5000 not charging to 100%

Good afternoon all,

This is the first time I am using the pylontech UP5000 batteries and I cant get them to charge above 86%, or more specifically 51.53V. The system is a Cerbo, a Quattro, and the pylontech batteries.

[image]

[image]

This is not my first time setting up a Victron with the Pylontech batteries, and I thought it was pretty straightforward up until now.


I have been through https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom

and all of my settings are exactly as they state here, with the exception of the DVCC.

It looks like the items on the Live page are outdated as the DVCC is now forced on. SVS is forced off, STS is forced off. (I have checked past installations and I see this is now true on all my installations)

In addition to the above the following settings are set:

Limit charge current: Off

Limit managed battery charge voltage: off

SCS : off.

[image]


I also have confirmed the battery and the Cerbo are communicating with the parameters coming through as expected. The BMS CAN is set up correctly and I have no errors.

[image]

Additionally, I see that the cell data is now available. I don't know if this is just a Cerbo thing or a UP5000 thing. But I think it's cool.

[image]

History:

When I first charged the battery it charged to 100%, which was at 51.53V. Over time that 100% has dropped to 86%.

What I suspect is that overtime the cells have balanced, which causes the 51.53V to equal a lower SOC. This is just my opinion and could be incorrect.

I dont know if anyone has any ideas on what I can do differently, or if I am missing anything. as at this point, I don't know how to get it to charge to 100%.

ewalderasmus asked
waburger edited ·

7 Answers

Why is my GX allowing 0.5A of charge current when set to 0A?

At first I thought this was a Batrium issue:

https://community.victronenergy.com/questions/166158/why-is-my-batrium-allowing-low-current-charging-wh.html

However, when I set DVCC to 0A, it still allows up to 0.5A:

[image]


[image]

BMV-702 is the configured battery monitor.

MPPT charging is clearly being throttled, but it's allowing charge when it shouldn't.

I can set GX current limits at other times, and it doesn't go over, e.g., if I set to 30A, It will usually peak at 29.7A or something like that.

This is a concern for Lithium battery charging below freezing.



snoobler asked
snoobler answered ·

3 Answers

DVCC and SmartShunt as generic source/solar charger?

https://www.victronenergy.com/media/pg/Cerbo_GX/en/dvcc---distributed-voltage-and-current-control.html#UUID-34a4601f-5b47-faa7-9b06-dc557696f5fc

Limiting the charging current with DVCC will compensate for the current measured by a SmartShunt configured as DC-load.

Will it also reduce the charging current of a MultiPlus/Victron MPPT if there is also current coming from a non-Victron charging souce (or Orion-Tr Smart) measured with a SmartShunt set to generic source/solar charger?

Example DVCC CCL set to 50A and 30A are coming from a non-Victron charging souce (or Orion-Tr Smart) -> the charging current of a MultiPlus/Victron MPPT will be limited to 20A.

Matthias Lange - DE asked
Matthias Lange - DE answered ·

1 Answer

Multiplus + CerboGX + FeedIN on + DVCC

Hello.

Does anyone have experience or knowledge of how to set the maximum charging in DVCC if I have feed to grid enabled? If I have it disabled, setting the maximum charging current DVCC works, but if I enable the feed, it ignores any settings and is able to push 100-150A into the battery. I received information from the distributor that this is not possible, but nowadays, when virtual battery services are provided, it would be nice if charging could be controlled.

Example:


Production 4000W
Household consumption 500W
Battery charging 100W
The rest to GRID 2500W

Is something like this possible?

Tibor Kocsis asked
Tibor Kocsis commented ·

2 Answers

Sharing Voltage & Temp data across a GX system

Hi: I have a CCGX on my boat, to which is connected a MultiPlus 12/3000 (via VE.Bus); and a non-Bluetooth MPPT 150/70 (via VE.Direct); and a SmartShunt (also via VE.Direct) on the AGM House bank negative. I want to be sure the MultiPlus and the MPPT are getting the best possible Volts and Temp data to optimize their respective House bank charging efforts. I have looked at the DVCC document but am still not absolutely clear....I do have latest firmware on all devices.

TEMPERATURE: The MultiPlus has its own temperature sense cable connected directly to a negative centre-battery terminal on the multi-battery House bank. The SmartShunt likewise has its own temp sense cable connected to the opposing positive centre terminal. I do not want to rely at all on the MPPT's internal temp sense capability.

VOLTS: the MultiPlus does NOT have a dedicated volt sense cable connected. It and (I presume) the MPPT are sensing House bank voltage at their respective output terminals

So here are my questions, first related to temp sensing:

  1. Is the temp data sourced directly from the Multi's dedicated temp sensor, the best temp source for the Multi vs temp data coming from the SmartShunt via the CCGX and VE.Bus?
  2. Does the temp data sourced from the Multi's dedicated temp sensor get transmitted via VE.Bus back to the CCGX ....and if Yes, is it available via VE.Direct to the MPPT?
  3. If both Multi-sourced and SmartShunt sourced temp data are available to the MPPT, is one or the other likely to be more accurate? AND can the MPPT be programmed to prefer one source over the other?

Then on voltage sensing, I understand that connecting a dedicated Volt sensing cable between the Multi and the House bank will give more accurate Volts data. Assuming this is done and similar to the temp questions above:

  1. Is the Multi's volt sensing data available to the CCGX via VE.Bus and then to the MPPT?
  2. Is this likely to be superior Volt data for the MPPT than its sensing at its own terminals?

Multi & MPPT are equi-distant from the House bank and each pathway is equally easy (!) to cable. Thanks in advance for your help.

aquabelle asked
aquabelle answered ·

2 Answers

DVCC with a VE.Bus BMS and Cerbo GX

I’m exploring options for using DVCC to protect a Li Smart battery. I know that I can use a Lynx Smart BMS in conjunction with a Cerbo GX to do this by connecting VE.Can on the Lynx Smart BMS to BMS Can on the Cerbo GX, and enabling DVCC in the Cerbo GX.

Can I do something similar with a VE.Bus BMS? In searching for the answer, I came across this statement in the CCGX manual… “DVCC can be used without any problem. The same is true for Victron Energy lithium batteries with the VE.Bus BMS”. However, the VE.Bus BMS manual makes no mention of DVCC, and it’s not clear to me how one would connect the VE.Bus BMS to a Cerbo GX to allow this. Would one connect VE.Bus on the Cerbo GX to the connector labeled MultiPlus/Quattro on the VE.Bus BMS? I have no inverters in my system so I’m not using VE.Bus for anything else.

My end goal is to have the ability to control an MPPT 100/50 which is connected to a Cerbo GX via VE.Direct. Since the MPPT 100/50 only has one VE.Direct port, I don’t have the option of controlling the MPPT 100/50 via VE.Direct with a non-inverting remote on/off cable.

pcg asked
Kienan edited ·

2 Answers

Not getting full DC charger output from parallel mp2

As the title suggests I am not seeing full DC charging output from parallel multiplus 2's. I have 2 MP2 24-3000-70-50 2x120 in parallel. Ac input feeds from the ac in junction box are the same size and length, as are the ac output leads to the junction box. Both ac in and out are 12/4, the manual is very clear about not oversizing the ac wiring for the purpose of balancing between the 2 multi's. I have checked and the multi's are within less than .5 amps of each other under various load conditions. The DC side is fed from a lynx distributor with same size and length wire going to both units. (0000 wire connects 400ah lifepo4 battery bank to the lynx, and 0 connects each inverter to the lynx. Initially each inverter was connected to the lynx with 2guage and I thought to try different size when I wasn't seeing full DC output but no change) everything is connected to a cerbo and I also have a smart shunt. I am only seeing 120 amps combined from the inverters in bulk. I have confirmed that each inverter will put out the full 70 amps in stand alone. The battery bank can take 1c charging (the full 400). If I start the RV and the alternator starts to supplement the inverter charging the batteries will take way over 140 so I don't believe it is a limitation anywhere in the system. DVCC is enabled but these are self managed batteries so no bms connected to cerbo and only shared voltage and current are enabled in DVCC. Max charge current is set to 250.

Unfortunately my clamp meter only reads ac amps and not DC so I can't tell if both inverters are throttled back equally on charging or not. Oh and the firmware is 497. Any ideas? Or is this one of those "it is what it is" situations? Same behavior on shore power and generator.

derrick thomas asked
Adam commented ·

2 Answers

ESS + DVCC - MPPTs overcharging battery when feed-in limit is reached.

Hi there,

I have a DC coupled system:

2x 150/70 Smart Solar MPPT

1x MP 48/5000/50-70 II

15kWh LFP (Polarium).

7.2kW PV array.

ESS and DVCC are active.

There is some anomalous behaviour, when the grid max feed-in rate is reached (~4200w), excess PV power is dumped into the battery beyond the absorption/float voltage, causing overcharging of the battery.

I understand the MPPTs are externally controlled by the Multi, and go to maximum power when controlled by ESS feed-in, but it seems like an oversight for the Multi to allow the MPPTs to dump excess PV into the Batteries when the feed-in is at it's maximum rate?

I understand I can throttle the MPPTs manually using max charge limit to stop this behaviour, but that wastes PV potential when I have to charge the battery and have AC loads also.

Am I doing something wrong here?

Advice much appreciated.

lonesom asked
lonesom answered ·

2 Answers

Clarifying DVCC

I want to just make sure I have my thinking correct here:

DVCC is only relevant in systems with an external BMS. With batteries that do not have BMS Comms eg. lead or unsupported Lithium, whether DVCC is on or off, the programmed parameters on the inverter/charger/mppt are used and any limits set in the DVCC menu are ignored.


Is this table accurate:

[image]


Further to this, the presence of a SmartShunt has no effect on DVCC at all.


We have a site with a Lithium battery (in a golf cart) which does not have BMS comms and we want to use DVCC to set charge current limit between MPPT and MultiPlus but it is being ignored. We noted also that programmed Maximum charge voltage in DVCC was ignored when we tried to lower the voltage from DVCC menu. We have a SmartShunt installed.

Warwick Bruce Chapman asked
Warwick Bruce Chapman edited ·

3 Answers

Is there a difference in system behaviour between allow to charge "no" and CCL = 0A

Question says it all.
I'm asking myself if a "allow to charge = no" triggered by the BMS has the same effect as a reduction of the Charge Current Limit to "0"

Or is there any different behavior of the system?

mascheihei asked
mascheihei edited ·

1 Answer

Why no DVCC with stand alone Lithium batteries?

Best I can see in documentation DVCC is not to be used with stand alone Lithium batteries like battle born. Can someone tell me why please?

Jeff Jensen asked
Jeff Jensen commented ·

4 Answers

Feature Request: Change default behaviour of DVCC override

I use the DVCC override feature on my Cerbo to effectively put my boat's battery into "Storage Mode." When I know I will not be using it, I'll use the DVCC functionality and "Limit managed battery charge voltage" to 13.2v and allow my battery to drift down to around 62% and stay there. Then, the day before I'm about to head out, I'll remote in and turn that off, letting the system fully charge the battery overnight.

The change in behaviour that I would love to see is that the default value for that DVCC voltage should be whatever voltage is being directed by the BMS. Right now, when I turn that feature on, it initially sets to 56.6v, which I then have to adjust down 0.1v at a time to get it to 13.2v. Additionally, that 56.6v would be dangerous/invalid on a 12v nominal system (or 24v nominal for that matter).

hjohnson asked
nickdb answered ·

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
kevstone122 answered ·

4 Answers

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