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njordan avatar image
njordan asked

What is the minimum number of Pylontech US2000 (2,4kWh) with Multiplus II 3000VA?

Hi,

i plan to go with my house into ESS (battery storage) and would like to buy Multiplus II 3000VA + VenusGX + EM24.....+ Pylontech 2,4kWh (to start small)....US2000.


I've seen some shops selling this combination, and was rather sure that this is perfect for me. But now i had a chat with a dealer who completely tried to unconvince me and not go buy an US2000 as he had several problems with broken BMS as the MPII would take huge turn on currents for the CAPs inside the inverter that the US2000 is not able to handle and the BMS / Mosfets would/could die.....

So now i'm confused.....a bigger BATT is not what i want to invest right now....but if US2000 is likely to break sooner or later its not the deal i want either.....


So i would like to know/see if some of you have experience with Pylontech & Multiplus II....and if a small US2000 really will not work well/and end up with broken BMS.....


For me its strange as both companies state that they work together,.......

On the other hand i googled a lot but could not find the behaviour the dealer told me happens many times......


BEst Regards,

Norbert






Multiplus-IIPylontech
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8 Answers
ejrossouw avatar image
ejrossouw answered ·

Hi @njordan For your size inverter you need min two batteries. If your inverter runs at full capacity pulling close to 46A and not even to mention startup spikes, the nominal 25A of the Pylontech will not be nearly enough. As for startups, again only a problem if you keep shutting down and starting up the system, which should not happen unless for maintenance or firmware upgrades and certain system setting changes. Others are probably more qualified than me on the topic, but with two batteries you will be ok. Also note that discharging lithium fast is also not good in the long term and don't expect battery warranties to be honoured if you did not follow the manufacturer's guidelines.

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njordan avatar image
njordan answered ·

As i do not need power to balance more than 1000W (short period of time like Espresso machine - typically much less at night - like 100W) - i guess this would not be the problem (?) - but as you also mentioned the spikes due to the CAPs.......do you know of any cases that broke the BMS while starting up?

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Rob Duthie avatar image
Rob Duthie answered ·

Hi

I run the same system with 4x US2000 with no problems at all, i started with 2x then upgraded to 4x, when you what to run over night with loads of 250 to 400 watts it lasts all night and i still have capacity of 50 % in the morning.

Yes the min is 2x US2000 i would use. You can set the inverter to limit power output injection anyway so you can run a smaller pack of US2000 packs.

If you run the inverter at full power of 3kw, yes on a 1x US2000 will load it up to much and the on board BMS will shut you down, so need to limit power to be safe.

Regards

Rob D

RD Electronics & Electrical

Rotorua

NZ




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ejrossouw avatar image ejrossouw commented ·

Small, but important for sizing calculations. The Multi is 3kVA and 2.4kW.

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chippy-145 avatar image chippy-145 commented ·

i am seriously thinking to replace my lux with a multiplus ii does the multiplus need any thing extra to use pylontech batteries can bye a kit through meodotech at a reasonable price there isnt much about using the multiplus with pylontech on any of the web pages or on youtube only moving from the lux because its so temprementle and a poor web page and its chinese getting really fed up with very poor copies of electrical equipment coming from them theyre even copying mk sockets hope you can help me in making a decision to buy

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dayandnight avatar image
dayandnight answered ·

Hello @njordan,

your idea is good and possible to realize with two pieces of USB2000. To do it with only one unit it is out of specification. I can't recommend. What about a PV-system? Only in combination with a PV system it makes really sense. Or do you want to use it as USV and backup, or for off-grid?

Further I would recommend to buy a Multiplus-II GX, instead of a Mulitplus-II. The Multiplus-II GX is the version of the Multiplus-II with builtin GX unit. So you do not need a separate Venus GX device and it is much less equipment and less work to do wiring. Do not forget to buy a MK3 unit to start updating and programming with VE-config and get the right cable for the communication from the GX-device to the pylontech batteries. Over all it is a good solution and works well, nevertheless it needs some work and time to set up and you need to know what to do or you need a good partner / dealer with know-how where you buy.

Have success - DayAndNight

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njordan avatar image
njordan answered ·

Thanks for the feedback.

I know about the Multiplus GX, but don't you think from failure perspective its better to split it up in VenusGX and simple Multiplus II? Of course you would be more compact and have less cables arround you.


I'm electrical engineer with a lot of experience in craft work. Do you think with manuals and commuity help its "easy/possible" to do the configuration myself?


@SolarPower....i have a 2kWp Solar plant (SolaX) and this extra installation should swallow all the negative power i provide to the grid right now.....


Is there any alternative to Pylontech in terms of price. My budget was about 3000€ which would easily cover the US2000 + Victron installation. But anohter US2000 would mean 4k€ which makes me now a little reluctant.

Going DIY Battery from my research does not bring that much budget advantage...as the cells simply cost that kind of money and you finally end up with Pylontech. Is this a correct view?


Kind Regards,
Norbert

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ejrossouw avatar image ejrossouw commented ·

If your highest consumer will max out at say 1000W, then I''d suggest looking a smaller multiplus? As for components or integrated, if you have space, go for components as it offers an upgrade path e.g. replace Venus with Cerbo or Colour GX. (Price is actually the same if you look at list price). At your budget end, BYD is a touch more expensive and there are few other options. Maybe look at Alpha ESS, but it is a completely integrated system.I think many battery failures can be accounted for through poor system design from the outset. Stick with combinations that are tested and supported if your are unsure of things.

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dayandnight avatar image dayandnight commented ·

Hello @njordan,

"don't you think from failure perspective its better to split it"

I was more than happy when starting my first installation to have one unit less to think about wiring and to have space where to put the unit. And I really underrated how much space is necessary for a three phase installation, especially for the wiring. So I was really glad not to have an extra GX Device.

If you have to ensure 100% fail-safe, you need spareparts on site in warehouse and than you need both units in your shelve. But this is more a discussion of a standpoint of view and it has to be decided based on the requirements of the installation.

It might be the feeling, too that with Multiplus-GX a "real" display is missing. But be honest I do all my access to the Victron by smartphone, pad, pc on-site local or by VRM off-site. I never missed a GX display.

Did you think about fuses? I can only highly recommend a fuse on the positive | plus cabling between Pylontech and Victron. From my standpoint of view it is a must. But you need it only for the positive cable. You can use a Lynx Distributor or you do your own distributor as I did.

"I'm electrical engineer with a lot of experience in craft work. Do you think with manuals and commuity help its "easy/possible" to do the configuration myself?"

It is possible, no doubt. For me it was fun to put the system together. There is all information which is necessary available at Victrons web-site and there is a lot of help and support thru the community. Only sometimes it is somehow difficulty to find fast and easy the right information at the moment when needed, because it is spread out over many pages and PDFs - but at the end all is there, well documented and easy to understand and to follow. And last, the additional money for a second pylontech is spent well. Go ahead! Have fun!

DayAndNight


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markussi avatar image
markussi answered ·

I use the Multiplus with only one battery. It works, but in ESS Mode the Multiplus drive only 800W from the Battery.


Regards

Markus

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njordan avatar image njordan commented ·

hm, that is really interesting. I anyhow would limit the power from the battery to what you wrote...so more than 500W is not required to come from the ESS system itself. Still my fear is that the Caps in the Inverter could break the BMS from a single Battery. At least one Dealer told me some bad experience here......and this is my only fear.....

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njordan avatar image njordan commented ·

Markus, can you tell me for how long you have been using a single US2000 now. Few months or even longer?

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Kevin Knoop avatar image
Kevin Knoop answered ·

@njordan I have a Multiplus II 3000VA setup with ESS and a single US2000 battery. It's been running for almost a year and has never missed a beat. No issues what so ever.

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njordan avatar image
njordan answered ·

One question that came up now - what would be an alternative Inverter (for Europe) that does the same as the MultiPlus2 + VenusGX......(ESS, battery storage - no directly connected PV) but on a lower power level (like 1000W). Many Thanks Norbert

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