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blufly avatar image
blufly asked

SOC 100% but only 12.1v

Hi Guys - I have 4 120ah sphere lithiums charging off 8 x 180w solar panel on my basestation - solar charger is a victron smart solar 150/100 and i also have a Smart BMV 712 - I had to put the van in my shed to do some maintenance so it wasn't in the sun - normally the system is continuously charged so never had a problem before and had it made to be able to survive in storage mode for at least a week - after 2 days the my ph lost Bluetooth connection but then it came back on again and was on 78% so didn't worry the next day all the power had shut off and nothing worked so i went to get a 3pin plug to hook up the caravan lead to the house and when i came back it was back on again and now says 100% SOC but only at 12.09 volts . I havnt plugged it into the mains yet and want some advise what to do as I havnt seen this before and usually sits between 13.2-14.2V and it defiantly isn't 100%SOC as hasn't had a power source or sun for 4 days now

BMV Battery Monitor
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Uwe Kilon avatar image Uwe Kilon commented ·

Hallo, was ist denn ein gutes Mass für den Ladezustand, wenn nicht die Spannung?

vg Uwe


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kevgermany avatar image kevgermany ♦♦ Uwe Kilon commented ·
Normaleweise BMV series. Zb. BMV712
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1 Answer
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nickdb answered ·

If power was completely lost, the BMV may automatically start at 100% when it is turned on. There is a setting for this in the menu - Battery starts synchronized.

It would then need a proper charge cycle to sort itself out.

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blufly avatar image blufly commented ·
hi nick - yeah it went completely dead -but shouldn't have in such a short time - Should i plug it into 240v and just let it charge up? and it will then reset after its fully charged or do i need to then re balance or do anything to the bank?
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nickdb avatar image nickdb ♦♦ blufly commented ·
Just let it fully charge itself, then do a normal discharge/charge cycle.

Perhaps post your shunt settings here and the battery specs. Does the pack have a bms you can connect to?

It sounds like either the soc isn’t tracking right (settings) or the battery bms isn’t happy.

Voltage isn’t a good measure of soc for lithium batteries.

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blufly avatar image blufly nickdb ♦♦ commented ·

hi nick - thanks for the reply

weather is really overcast toady and for the next few days so ive plugged it into the mains

it ran up to 12.3v and then has stayed at that level

i have attached the battery settings from the BMV - battery bank is 4 sphere 120ah lithiums, van is new in NOV 21 and I got the system upgraded with the xtra solar and victron 150/50 BMV712 and enerdrive 2600inverter

all these settings are as per the installation so im not sure if there correct?

any further help or advise is much appreciated as you know i have invested $$ into this so won't to make sure its operating correctly and to its capability



1654839076616.jpeg

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nickdb avatar image nickdb ♦♦ blufly commented ·
What are your charger settings?

There are a few variables at play here, I know you didn't use solar but let's have a look at the MPPT settings. I am not familiar with your inverter (Not Victron - Phillistine! ;) )

The BMV won't impact how the batteries charge, it should just be used as a reference.

If the battery isn't properly charging it would explain the short run time.

The question is why.

It could be charger/inverter settings. It could also be related to the battery BMS intervening, can you access this at all or is it a closed system?

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blufly avatar image blufly nickdb ♦♦ commented ·


charger settings from Mppt as follows

img-0712.pnglooks like there is an issue with the caravan control panel so wasn't charging on MAINS , Ive pulled the caravan back out into the sun and its started to charge again and is now at 13.02v



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img-0712.png (343.6 KiB)
blufly avatar image blufly blufly commented ·

battery bank is 4 x sphere 120ah LipO4 sealed and no Bluetooth to BMS


img-0711-2-small.jpeg

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img-0711-2-small.jpeg (38.5 KiB)
nickdb avatar image nickdb ♦♦ blufly commented ·
It won't work so well without mains :)

I see you're using a lifepo4 charger preset. Any reason you haven't created a user-defined profile with the manufacturers specific voltages?

If a cell gets too high it will trigger the bms to protect and that will throw the whole system out.

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klim8skeptic avatar image klim8skeptic ♦ blufly commented ·

You could probably tweak the "charged voltage", "Charge Efficiency Factor" and "Peukert Exponent" in the BMV's settings (to reflect lithium settings).

BMV Youtube tutorial.

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