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solarmanu avatar image
solarmanu asked

Discharging instead of charging on dash: is my setup actually working? Or are these issues serious?

Hello,

I'm a newbie with a new installation in East Africa (Victron Multiplus 5KVa, Smart Solar 250/100, Venus Cerbo GX, 10 solar panels of 345W and one Weco 4k4 battery). It's fully off-grid.

There seems to be a few issues with the setup and I was hoping some here would know how to fix it, or let me know if there's nothing wrong. Any help would be really welcome, thanks!!

I had a professional install this but there seems to be mistakes in their setup (e.g. initially there was no power usage showing on the dashboard) and so I want to check that everything is in order.

1 - The charging lights on the 4k4 Weco battery always indicate that it's discharged, even fully charged:

whatsapp-image-2021-11-18-at-072724.jpeg

2 - The Cerbo dashboard is showing the battery discharging when it's actually charging and vice-versa, like here:

whatsapp-image-2021-11-16-at-065411.jpeg



3 - At night, the system (fridge mostly) takes 0.05KWh of power on average for around 11-12h. It starts discharging from 6pm (until then it's 99% full) and charging from 6am. But it looses 1kWh during the night and the battery is at 70% charge in then morning (6am) when the sun comes back. I'm guessing my math is wrong but can't make sense of this.

whatsapp-image-2021-11-15-at-140536-1.jpeg


4 - Should the DVCC be activated (it is now)? I couldn't find out which settings should be used.

whatsapp-image-2021-11-16-at-072618.jpeg


5 - Bonus question: how bad is it to discharge the battery to 30-40% on some nights? Should I get a second one? What happens if it goes to 0%?

Thanks a lot!!

Manu

cerbo gxbatterysetup
3 comments
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marekp avatar image marekp commented ·
@Solarmanu

Is there external current sensor installed?

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solarmanu avatar image solarmanu marekp commented ·
I don't think so
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weco-uae avatar image weco-uae commented ·
Hello,

you battery is not maybe equipped with the correct Firmware.

Please upgrade the battery to the lastest version available.

If you have se the WeCo WiFi APP ( Or bluetooth) simpli tap on the notification area or on Firmware upgrade lacated in the third page of the APP.

This problem has been fixed on April 2021

Thanks

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11 Answers
nickdb avatar image
nickdb answered ·

Lithium batteries can be discharged lower without affecting their life, that's what they are designed for.

DVCC is a requirement for these types of setups.

The VRM dashboard sometimes gets confused when refreshing and will sometimes show discharging when it is charging batteries, it just gets out of sync but usually sorts itself out, a page reload resolves immediately - the remote console will show a more accurate view.

Weco isn't on the supported list for Victron, so you really need the supplier to confirm what settings are required and to verify the BMS is operating correctly.

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solarmanu avatar image solarmanu commented ·

Thanks. Helpful to know about the battery.

For the charge/discharge it is consistently wrong though, it's not a matter of updating.

See e.g. below. It's been night for 2 hours so it's definitely not charging.
20211118-194551.jpg

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kevgermany avatar image
kevgermany answered ·

Looks like a wiring issue as well.

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solarmanu avatar image solarmanu commented ·
Thanks. What would be the issue specifically?
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kevgermany avatar image kevgermany ♦♦ solarmanu commented ·
Wish I knew. Wiring diagr would help, but I guess you don't have one.
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Alexandra avatar image
Alexandra answered ·

@Solarmanu

The lights on the weko (coupled with the charge discharge reverse report) suggest something internally has not been connected right / in transport has disconnected? Thats a supplier related question. But is also related to why the charge discharge indication is backwards.

Is the Cerbo using the battery for the SOC report? I do know many lithium batteries struggle to track SOC with small loads. It may be worth putting a bmv or shuntt based monitor on the system.

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solarmanu avatar image solarmanu commented ·

Thanks! I think the Cerbo is getting the battery readings from the battery itself, see the screenshot. It's getting it wrong even for 1000W loads.


Could this wiring mistake have damaged the battery?
screenshot-20211119-055824-chrome.jpg

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Alexandra avatar image Alexandra ♦ solarmanu commented ·

Have you ever fully charged as shown on the weko datasheet? Check your settings and charge with what they show. Is the model you have the 4k4 Rack? This will help with soc and balancing.

I am thinking a cell balancing thing may be at play here?

Some batteries while balancing discharge a little bit to bring cells down to a manageable level then top up again.

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solarmanu avatar image solarmanu Alexandra ♦ commented ·
Most of the day the battery indicates 99% because we use much less than we consume. Is this what you mean by fully charged?

Sorry if I'm mistaken.

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Alexandra avatar image Alexandra ♦ solarmanu commented ·

Is the battery charging to the correct voltage? Ignore the percentages of soc for now.

When i say correct voltages i am referring the battery manufacturer recommended voltages for fully charged.

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solarmanu avatar image solarmanu Alexandra ♦ commented ·
Right now the battery is at 52.7V and spec is 51.2V. it's night so discharging. Is that the way it's supposed to be?

Thanks a lot for your advice!

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Alexandra avatar image Alexandra ♦ solarmanu commented ·
It would be helpful to know exactly what battery you have. Can you link a datasheet? Or a manual.

What are your setting on the inverter and the mppt?

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solarmanu avatar image solarmanu Alexandra ♦ commented ·

That's the specs for the battery
20211122-061030.jpg

The settings on the cerbo.

screenshot-20211119-055824-chrome.jpg

On the Mpptscreenshot-20211122-061757.jpg

This seems to be the manual for the battery

https://www.google.com/url?sa=t&source=web&rct=j&url=https://wecobatteries.com/oweephee/2019/06/pdf-stackable-4k4.pdf&ved=2ahUKEwj5kLbggqv0AhUnRvEDHY1BCiwQFnoECA0QAQ&usg=AOvVaw2pglSgjQugmYVrwFi7l8jW

Is that helpful?

Thanks!

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Alexandra avatar image Alexandra ♦ solarmanu commented ·
Yes helpful.
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kevgermany avatar image
kevgermany answered ·

Sorry, but given your comments in the first post and that the kit is new, this is one for the installer/victron. Is the installer an official victron dealer/agent? If so they have a support system.

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solarmanu avatar image solarmanu commented ·

There's no official Victron installer/agent where I live

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kevgermany avatar image
kevgermany answered ·

I've lived in Africa. I think I know what you're up against.

Hopefully the importer can help.

What I'd do is get some example wiring diagrams from the Victron website and if the installer didn't leave them, the manuals as well.

I'd collate these into what it should be, based on what connects to what. Match to your symptoms to try and narrow down the search.

I'd then trace the actual wiring and make a diagram. And compare to ecpected. Post it here, Good chance of someone spotting an error.

If this doesn't work, you should be able to pinpoint a component problem.

But as it's apparantly working, could be a simple issue.

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Alexandra avatar image
Alexandra answered ·

@Solarmanu

Looking at the datasheet for the battery that you linked there are several pieces of information I wanted to point out.

The charge current in dvcc should be set down to 60A. Thats the nominal rating for it according the datasheet.

The range of the bms is 46.3v to 57.8v, yours is set in DVCC to 55v but 56.8 on the mppt. (So within the range, that is good.) Not sure what the installer reasoning may be there with the 55v. Does the system charge to the 56.8v? The only issue that there may possibly be is cell balancing. Since I am not familiar with the battery I do not know what voltage balancing begins at and if it is passive balancing or not.

The mppt is set to the preset from victron, which is not ultimately a bad thing. If they have done that on the inverter then no damage will be done to the batteries from a settings standpoint.

The charging discharging information difference may just be a software issue. I am guessing here as I have never used weco. As mentioned it is not a fully supported battery so issues like that can be expected. It might be worth changing out the data cable to check to see if it is the cable or not?

Basically 100% charged should be at 56.8v and then the battery should drop down to float that is set at 54v. If it is doing that then they system is functioning correctly even if it is saying/reporting charge and discharge backwards.

The lowest you should ever discharge your batteries to is 46.3v.

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solarmanu avatar image
solarmanu answered ·

Thanks @Alexandra !

The contractor came so I was waiting to see if they could fix it. They tried a different cable, but still the same issue. It seems there's maybe an issue with the Weco battery itself, which is quite annoying as it's brand new. Now it's only charging to 95%. They're running some tests to confirm this. Will let you know!

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Alexandra avatar image Alexandra ♦ commented ·

@Solarmanu

Glad to hear there is progress. I also wanted to ask if you are running an official release on the GX device or a custom one?

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weco-uae-1 avatar image weco-uae-1 commented ·
Please contact us: service@wecobatteries.com

Our expert will then call you to fix your issue

Thanks

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solarmanu avatar image
solarmanu answered ·

It's an official release, the latest one. The technician also tried to get the battery reading from the Multiplus and the charging/discharging was correct.

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solarmanu avatar image
solarmanu answered ·

The people who did the solar setup are now saying that the Weco batteries are not compatible with Victron and that I need to get a different battery (spending more money). I'll make a post about this to warn others...

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weco-uae-1 avatar image weco-uae-1 commented ·
Hello, you don’t need to buy another model ( unless you want) you can just contact us and we can put in contact with our authorized installer in your area to properly install the battery.

Service@wecobatteries.com

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kevgermany avatar image kevgermany ♦♦ weco-uae-1 commented ·
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marekp avatar image marekp commented ·

@Solarmanu

Maybe you should contact the maker of the WECO batteries.

service@weco.uk.com

Their manual does not agree with "the people who did the solar setup".

Maybe they did not follow the manual.

https://wecobatteries.com/download/94/manual-4k4/7718/4k4-pro-r22_manual_v1-11.pdf

8.4
To set the CAN protocol to match the inverters communication protocol, select the inverter that you are connecting to from the list and press SET, wait for the positive feedback after the first communication with the inverter Using the Software available on>https://wecobatteries.com/download-area

If you look at the picture in this section of the manual, "VICTRONCAN" is an option that needs to be set.

screen-shot-2021-12-12-at-112535-am.png

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weco-uae-1 avatar image
weco-uae-1 answered ·

Hello

Please contact service@wecobatteries.com

The solution is much more simple…. The service team is available 24/h. Please contact us we can support remotely or via video call.

Kind Regards


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solarmanu avatar image
solarmanu answered ·

Thanks for the tip @MarekP and @WeCo-UAE

I was going to write an update.

The technician configured the battery (they hadn't done this) and it's now working fine. I had contacted the Weco commercial service a while ago and was initially told to ask the technician which I did but they struggled to fix it, although it was quite simple... It took a while to get this sorted but it's working fine now.

Glad it's sorted!

I hope the battery will work for a very long time!



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seb71 avatar image seb71 commented ·
Maybe post that settings change, to help others.
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