question

Stijn avatar image
Stijn asked

18S LFP Victron Quattro 48/15000/200-100-100

A Victron Quattro 48V has a max input voltage of 66V.

The EVE LFPs I plan to buy have a max voltage of 3,65V.

And thus I plan to use 18 in series giving me max DC voltage of 65,7V, instead of the conventional 16S.

/*

The following is NOT correct as stated by mvas underneath

However, Victron advises to bulk charge each LFP to 3,55V and then absorption charge them at 3,375V.

*/

This is correct:

Bulk charge until 3,55, absorption at constant 3,55 and then float at 3,375V

https://www.victronenergy.com/media/pg/Manual_BlueSolar_100-30__100-50/en/configuration-and-settings.html

So my max 18S voltage would be 63,9V, well below the 66V for additional safety margin.


Any reason this is ill-advised?


Thanks,

Stijn

Datasheet-Quattro-3kVA-15kVA-NL.pdf

EVE 304AH datesheet.pdf

48v battery
eve-304ah-datesheet.pdf (3.4 MiB)
datasheet-quattro-3kva-15kva-nl.pdf (338.0 KiB)
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4 Answers
Phil Gavin avatar image
Phil Gavin answered ·

Yes, 18s can be done. The 450V Victron MPPTs limit their output at that DC voltage, but all other Victron CCs and Multi's seem capable.

I theorized about this with a fellow forumite, @Jaco Reinecke. He started running 18S Eve cells and is quite happy with it.

Many BMSs are available that exceed 18s, but you may need to revisit fuses if they are not rated for 60V+.

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Jaco Reinecke avatar image
Jaco Reinecke answered ·

Jip, 18 cell 280ah EVE bank at 3.45v max per cell, with 3.375v float. I see no need to go higher, based on the graph.

Also, cells can shoot out to 3.65v in an unbalanced bank, so one wants to keep well clear of the max volts.

18 Cell - Excel.jpg


18-cell-excel.jpg (98.5 KiB)
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Stijn avatar image Stijn commented ·

@Jaco Reinecke ,


Thanks! What BMS do you use?

Where did you buy the EVE cells from? Happy with your purchase?

Something else I should take into account?


Much appreciated!

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Jaco Reinecke avatar image Jaco Reinecke Stijn commented ·

Bought the EVE cells from Amy on Alibaba. Grade A Batch Matched, very happy with them.

Using a JBD (Jiabaida) BMS, the 20S 200a one.

Interfacing the JBD BMS with the Cerbo using Louis software: https://louisvdw.github.io/dbus-serialbattery/

Louis driver shows all 18 cells individually on the Cerbo. That one can spot 'n problem quickly, remotely too. :-)

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Stijn avatar image Stijn Jaco Reinecke commented ·

Cool, I'll check all that out...but eeuhm, Amy? How can I find her on Alibaba?


Am in negotiations now with Daisy Efest from Docan Power.


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Stijn avatar image Stijn Stijn commented ·
@Jaco Reinecke


I must say that the info on JBD BMS's is very limited. Is the quality any good? Which one exactly did you buy? Cheap yes, but does not really inspire confidence.
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Jaco Reinecke avatar image Jaco Reinecke Stijn commented ·

JBD-AP20S003 and JBD-AP20S004 as well as JBD-AP20S003S.

It is a passive balancer, one can add an active balancer, new models seem to lead towards that, active balancer added, but the cells, the cells are the key, when balancing becomes an issue.

I am only interested in BMS'es with Bluetooth AND RS485 ports, so I can use the App, and see all the data, settings, and alter settings on the BMS, whilst it is connected to the Cerbo.

It pretty much does what it is supposed to do, the accessibility, for me, was the key. The main function of a BMS is to disconnect the bank to protect the cells. It does that quite well.

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Jaco Reinecke avatar image Jaco Reinecke Stijn commented ·

BMS'es from:

Dongguan Jiabaida Electronic Technology Co., Ltd.
Contact name: Fidelia Xiao
Registered company address: CN,Guangdong,Dongguan,2nd Floor, Plant 6, No. 40, Baoyuan 2nd Road, Lianhu 3rd Industry Zone, Tangxia Town
Company tel: 86-0769-28960405
Company email: xf0829wdn@163.com


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Jaco Reinecke avatar image Jaco Reinecke Stijn commented ·

EVE cells from Shenzhen Luyuan Technology Co., Ltd.
Contact name: Wan Amy
Registered company address: CN,Guangdong,Shenzhen,14c, Jinmin'an Business Hotel, No. 529, Bulong Road, Bantian Street
Company tel: 0086-0-13425163957
Company email: luyuansale@163.com

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Stijn avatar image Stijn Jaco Reinecke commented ·

Thank you!


Just looked at the EVE cells 304Ah from Shenzhen Luyuan Technology, they are 120,67 EUR starting from 200 pieces. At Docan Power, they are at USD 114 starting from 100 pieces, so 104,7 EUR.


Will further look into the JBD info you provided.


Thanks a lot!


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mvas avatar image
mvas answered ·

You wrote...

However, Victron advises to bulk charge each LFP to 3,55V and then absorption charge them at 3,375V.

That is NOT what the manual says.

It says ...

Bulk Charge until 3.55 volt/cell, then hold at 3.55v/cell during absorb.

Float at 3.375v/cell.

If you want to "play with fire'' then you can try to run your 18S battery bank voltage near the Quattro's maximum battery input voltage.

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Stijn avatar image Stijn commented ·
You are right, misread the columns.


However, is 66V then an unsafe limit?

Serious question...if rated until 66V, isn't it rated to operate safely until 66V?


Thanks for the answer.


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klim8skeptic avatar image klim8skeptic ♦ Stijn commented ·
@Stijn charging is limited to 64v.
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Stijn avatar image Stijn klim8skeptic ♦ commented ·

Hi @klim8skeptic,


Could you point me to where it says that max charge voltage is 64V? Did a quick search through both the PDFs here included, can't find any mention.


Much appreciated!

29694-MPPT_solar_charger_manual-pdf-en.pdf

handleiding-victron-quattro-algemeen.pdf


In the MPPT manual, I saw that some standard equalising settings go up to 68,4V!

screenshot-20230703-110505.png


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29694-mppt-solar-charger-manual-pdf-en.pdf (6.4 MiB)
handleiding-victron-quattro-algemeen.pdf (2.6 MiB)
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jeanmarie avatar image
jeanmarie answered ·

I would just add that:

- 3,45V correspond almost to a SOC = 99.9%, not essential to go higher

- some legislation consider passing 64V as not anymore low voltage and impose expensive measure in such case (and not respecting your legislation means you are not covered by any insurance)

- depending of the BMS models, SOC is adjusted to 100% by reaching some higher voltage. If the selected BMS is not able to sync the SOC to 100 when reaching a defined float value like 3,45, then you'll have a drift of the SOC, even with batteries full. With a 16S you can force to a higher voltage to resynch, if you are at the high limit and this is not possible, it could lead to some functioning/displaying issues

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