question

Hugo Russouw avatar image
Hugo Russouw asked

MultiPlus-II 48/5000 Low Battery

I have Pylon batteries connected to my MultiPlus-II 48/5000.

The batteries are fully charge at 53V and I did set the MultPlus-II settings as stated in the Victron & Pylontech US2000B Manual, VEConfigure Settings.

The Multi Battery LOW RED LED is flashing and if I disconnect main, the Multi switch off after 30 seconds because of low battery even if the battery is still 53V.

What am i missing??

Multiplus-IIPylontech
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offgridsystems avatar image offgridsystems commented ·

I also have this problem when using Pylontechs on either Off Grid or ESS mode. It seems the published low voltage cutoff values are incorrect. If I reduce these values to a lower value, the problem goes away. Of course the values I have used are guesswork and may cause problems with Off Grid systems during the Winter if the voltage does get too low and the batteries shut down.

Currently I am having to drop the low voltage warning well below 50v, typically 46v to stop the warning light flashing, even though battery voltage is well over 50v, typically 52v on delivery.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ offgridsystems commented ·

Hi @offgridsystems

The 'low voltage warning' on inverters is something you can ignore on lithium battery systems, just make sure the low voltage disconnect voltage is according to the manual:

https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom

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offgridsystems avatar image offgridsystems Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Hi Daniel.. Thanks for the quick reply. I use the exact settings in the manual, but when the system starts, the multi flashed low battery. I have to back the published settings down to lower voltages to get the system to start.

This has now occurred on all 5 Pylon systems I've installed over the last few weeks.

Chris Rudge

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ offgridsystems commented ·

Hi @offgridsystems , Chris,

When starting up with AC on input AC1, does it start up normally?

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offgridsystems avatar image offgridsystems Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

When used on an Off Grid system, the inverter will not start up and just has a low battery indicator flashing. We tried to run the generator to try a few things and possibly overcome the low battery problem. The Multi still did not start.

If I program the low battery warning to threshold 45v, it all works well.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ offgridsystems commented ·

Hi @offgridsystems
I've sent you an email about this, did you recieve it?

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James Minnie avatar image James Minnie commented ·

We also have a Multiplus II with BMZ ESS 7.0 (48V) batteries. A low battery warning and at times a low battery fault occurs when the inverter starts although the battery volts is at 58V. Low battery alarm settings are below 48V.

Any advice?

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ James Minnie commented ·

Hi @James Minnie

Is this the 'Helderberg Solar' site?

If so, there is something wrong with the battery, or the connection to it.
Either a fuse is blown, or the battery is not connection internally.

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James Minnie avatar image James Minnie Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Thanks Daniel, problem was solved. Partially blown Pyro-Fuse in BMZ battery pack.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ James Minnie commented ·

Thanks for the update!

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Russell avatar image Russell commented ·

I also get a flasing RED low battery on Victron MultiPlus-II 48/3000 firmware 470 , ESS assistant & Pylontech US2000B. Low battery warning goes away if I delete ESS assistant.

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Hugo Russouw avatar image Hugo Russouw Russell commented ·

Hi russellw

See that you enter the correct values for the Dynamic cut-off in the ESS.

1613381908740.png

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1613381908740.png (16.4 KiB)
psadeazevedo avatar image psadeazevedo Hugo Russouw commented ·
Thank you! This resolved my problem. My cut-off voltages were set to 46.50. Setting all of them to 46.00 resolved the problem, but the question is what's the problem with the 46.50 ?
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2 Answers
Paul B avatar image
Paul B answered ·

Hi Hugo

Check the settings in the VE config under the inverter tag and adjust if required


Also if you are using the ESS then what settings did you set. re low voltage settings and adjust to suit your batteries.

if you are using other assistants then consider what setting you added and adjust these so that the low voltage reflects your type of battery.

In practice you will need to use logic and adjust any low voltage setting to suit your needs, with out going to low and outside the battery specs for there low voltage settings.

Currently there is a fault in the forum and I cant past any screen shot examples for you and I suspect you cant post any for me as well.



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rnieckau avatar image
rnieckau answered ·

I have found the Low Battery Warning to illuminate automatically once the 30% SoC threshold has been reached, via the internal BMS of the Multi.

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