question

florianmaerz avatar image
florianmaerz asked

How much energy does a pylontech US2000C consume in standby?

I cannot find any information how much energy a Pylontech US2000C needs in standby.

With standby I mean: The battery switch is "ON" and the battery was "started" with the red button. The battery is disconnected to any consumer via battery switch.

Background: The system is installed in a mountain hut. To keep things easy for others I want them to use the battery switch only and not mess with any additional switches in my installation. Sometimes the hut is not used for weeks, even 2 or 3 months maybe.


help very much appreciated. Thanks :)


Lithium BatteryBMSPylontech
2 |3000

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

4 Answers
Alexandra avatar image
Alexandra answered ·

@FlorianMaerz

Pylon does not state this at all in any manual that I have read so far. Most Lifepo4 (i think it can depend on cell age as well) state it can be up to 3% self discharge per month. I have not seen that kind of level on any of the batteries I have used so far though.

Pylon in the install manual do under part 7 - remarks - maintenance say this ....

1665151668613.png

It is likely that after being idle for longer periods it will switch itself off anyway. Most BMS controlled batteries do that when left alone with nothing connected for long periods.


1665151668613.png (63.1 KiB)
2 comments
2 |3000

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

florianmaerz avatar image florianmaerz commented ·
Thank you very much for your fast answer.


I will try to contact Pylontech and ask:

- How much energy does the battery need if:

a, the ON/OFF switch is "ON", but the "red button" was not pressed to start the battery

b, the ON/OFF switch is "ON" and the red button was pressed to start the battery

In addition I will ask: does the battery switch of automatically if not connected to a consumer after a certain period.?

Maybe I am lucky and Pylontech does answer. If they do I will copy their answer here in the comment section.


2 Likes 2 ·
florianmaerz avatar image florianmaerz commented ·
Unfortunately, Pylontech did not answer my questions yet.


I did a very rough estimate on my own:

1) I leave the battery "ON/OFF" in the "ON" position and activate battery with the "red button"

2) I disconnect the batteries from any consumer via battery switch

3) Every 24h I turn on the battery switch and read the state of charge as shown by the cerbo gx

4) it turns out that the batteries loose roughly 1% a day

5) US200C: 2400wh * 1% = 24wh a day => 24/24 = 1W self consumption of the batterie

0 Likes 0 ·
Rob Fijn avatar image
Rob Fijn answered ·

Hi florianmaerz, good question.
Maybe someone can measure this.

I would not assume they go OFF if nothing happens on the load/charge side.
Maybe you can still have the PV connected to the battery, and have the other loads and switch OFF by the user. Set the charge profile with some safe voltages...

Regards, Rob


1 comment
2 |3000

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

kevgermany avatar image kevgermany ♦♦ commented ·
Not sure how to measure without invalidating warranties, except by leaving one for a few months and measuring what goes back in when you recharge.

@FlorianMaerz I think good design, labelling and recovery instructions. For instance if you follow @Rob Fijn suggestion to leave PV charging ON, label these switches as leave ON.


1 Like 1 ·
florianmaerz avatar image
florianmaerz answered ·

Pylontech did answer my question: they state that a US2000C needs around 2W in "standby" mode. As explained before standby was defined as: Battery switch is "ON" and battery was started with the red button. All consumers disconnected.

That means that a US2000C with 2,4kwh looses approximately 2% a day (2*24 / 2400)

2 comments
2 |3000

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

Alexandra avatar image Alexandra ♦ commented ·

2.4kwh is 2400w

2400w ÷ 2w/day = 1200 days. So really almost 3 years to fully discharge....

So your daily percentage will be more like (2/2400)*100 = 0.083%


It is more in keeping with the under 2% per month self discharge most manufacturers advertise.

And thank you for sharing the feedback from Pylontech.


0 Likes 0 ·
florianmaerz avatar image florianmaerz Alexandra ♦ commented ·

That is not correct I think

2,4kwh is 2400wh.

A permanent consumption of 2W means: 2400wh/2w = 1200h

1200h/24 = 50 days (until full discharge)

That means 1/50 = 2% discharge a day

0 Likes 0 ·
s3b avatar image
s3b answered ·

Thank for your feedback @FlorianMaerz . I search since few day why my system lose about 1% every 9/10H with battery in standby mode. I mesure the cerbo gx consumption ( about 75/90 mA on 48V battery , 30/40mA with 2 MPPT VICTRON ). On VRM 0mA take on the Battery. So if the US2000C use 1Wh in stand by mode, if I add the cerbo gx and the MPPT, I can arrive to 1% every 9H of battery ....
On this picture, the evolution of battery state ( -1% every 9H with only cerbo GX and 2 MPPT )

capture-decran-2022-12-06-a-212807.png


3 comments
2 |3000

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

dirk-s avatar image dirk-s commented ·
I have nearly the same discharge with my 6*US3000C with my Multiplus II GX 5000.
1 Like 1 ·
s3b avatar image s3b dirk-s commented ·
Thank for your feedback ;)
0 Likes 0 ·
s3b avatar image s3b dirk-s commented ·
a solution to prevent this the winter ? what do you do ? every -5% of discharge under the SOC, the multiplus force the charge to the SOC
0 Likes 0 ·