question

moeterxl avatar image

DVCC limiting charging current - Multigrid, Venus, MPPT, Fronius and Pylontech

I`ve got an problem with DVCC on while charging the batteries. My system: Multigrid 48/3000/35-50 with Venus GX and two connected Pylontech US2000 Plus. A BlueSolar 150/35 is DC- connected to the Multigrid. My Fronius Primo 3.0-1 is AC- connected to the output 1 of the Multigrid. The gridmeter is an ET340. The system work fine. But if i activate DVCC the charging current will slow down to about 20A and the excess of energy is load to the grid. If i deactivate DVCC the full energy (about 30A) is load to the batteries. I want to load all the energy to the batteries. All firmware is up to date. Whats the problem?

MPPT - Solar Charge ControllerVenus GX - VGXPylontechDVCCmultigrid
2 comments
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

can you show what the BMS parameters are in the Remote Console?

Please confirm the current firmware versions on all devices, most specifically VGX and Multigrid.

There have been improvements made in this regard.

4 Answers
moeterxl avatar image
moeterxl answered ·

Now i`ve isolated the batteries and above 16°C the charging limitation is gone up. Later i want to apply a battery heating / cooling system based on 230V an d switched by an external sensor. Problem solved. Thanks a lot.

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

moeterxl avatar image
moeterxl answered ·

Hey Guy,

there`s the answer from Pylontech Support. Sorry, i dont`t get any diagrams about the temperature and the allowed charging current.

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

Hi Kay,

Thank you choose our product!

Just like telephone battery cell, all normal lithium battery will get hurt in low temperature working condition specially in charging mode. For longer cycle of life and calender life we limit the current in low or high temperature. You can google the knowlage of "Lithium dendrites" if you have interesting.

So our BMS of battery work together with inverter to limit the current to protect our battery cells. It is intelligent design.

My proposal is:

  • Install a heating system for our battery (heat in the cabinet). Rise the temperature above 10℃. And the battery's comfortable temperature is 18~28℃.

Thanks and best regards!

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

I´ve checked the VGX and Multigrid to control the internal relay in relation to the batteries temperature. So it should be possible to built a battery heating module. Unfortunately i haven`t found any free configurable function at the assists to use the BMS temperature. There`s only temp high / temp low alarm and pre alarm (LED) available from Multi. Should i use an external temperature sensor wired on Multigrid even though the temperature is available from BMS? I think the best option is to use the BMS temperature for switching the relay of VGX or Multi according to a set temperature. This is an important feature for heating or cooling a battery system to his comfortabel temperature.

Thanks for your opinion

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

moeterxl avatar image
moeterxl answered ·

Hi Guy,

today i`ve tested the new firmware 2.23. It`s the same problem like before. See the uploaded PDF ESS.pdf the requested parameters. The battery set the DCL to 50A and the CCL to 20A by BMS? My MPPT shows already an CCL = 35A (=maximum). What`s wrong?


ess.pdf (215.3 KiB)
4 comments Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Ah so it is the BMS parameters, I'd start by checking the battery manual / asking battery distributor, could it be that the batteries are at a low temperature?

Hi...

See Pylontech Manual: Working temperature range is from -10 to 50, (Charging 0~50; discharging -10~50) with excellent discharge performance and cycle life.

The battery temperature is about 9 - 15 degree all the time. All alerts at BMS are OK. By the way the system works perfect with disabled DVCC. The battery uses the maximum available current for charging. The DVCC- function is important for me? Whats different in detail to disabled DVCC?

If you want us to read the Pylontech manual, you'll at least have to link to it..

But DVCC is important for preventing to much current in / out of the batteries, You'll void the battery warranty otherwise.

The battery not giving the expected charge current is something you'll have to pick up with Pylontech support (after checking you've correctly wired your batteries)

Are you sure both batteries are 'online' or maybe only one is seen?

It is most likely a restriction of the current by the battery BMS due to low temperature.

A similar issue was discussed here - https://community.victronenergy.com/questions/6220/pylontech-charge-current-limit.html

I have been unable to get a copy of temperature derating table for the Pylontech batteries. I do have the similar one for BYD.

It is not documented in Pylontech manuals. Please contact your battery supplier and ask them to provide it (and then post it here so that we can also know for others in the future).

It would appear that everything on the Victron side is behaving as it should. The DVCC feature is receiving the instructions from the Pylontech BMS to reduce current, and it is.

Disabling DVCC to bypass this restriction will be logged inside the Pylontech BMS and can void your battery warranty,

moeterxl avatar image
moeterxl answered ·

Multigrid: Product: 2690 Firmware: 433

VGX: Product: 20181201144037 Firmware: 2.22

MPPT150/35 rev.2: Product: 0xA04B Firmware: v1.39

ET340: Product: b00d Firmware: 3

3 comments Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

moeterxl avatar image moeterxl Guy Stewart (Victron Community Manager) ♦♦ ·

Hi Guy,

i`ve updated the VGX to the new version 2.23 from today. But now it`s a little bit cloudy so i couldn`t test it . I`ll write back if it works. Thanks for your fast answer. Sincerly - Kay

The information that Boekel asked for in the parameters menu of the battery on the Venus-device is also important.