Multiplus 2 24. Is it possible to use a 22v battery?

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kane-1 asked Aug 21, '21

Multiplus 2 24. Is it possible to use a 22v battery?

There are currently 12 cells connected. I have a total of 22 intact cells. 2 cells are missing to make the 24v set complete.

Can I put 2x11 in parallel so the voltage would be 22v instead of 24v? The battery size would increase from 225Ah -> 450Ah. It does not matter if the battery cannot be completely discharged.

What settings need to be changed?

About the system:
* Multiplus 2 24 3000va
* Gerbo gx
* Smart battery shunt.
* Mk3 USB
* Battery 225Ah Tubular plate Traction (22 x 2v cells)
* Alongside the battery are Maxwell BOOSTCAP® ultracapacitors to take out the sharpest spikes.
* ESS is enabled

Multiplus-II battery

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Matthias Lange - DE answered · Aug 21, 2021 at 07:08 AM

The 24V MP-II has a DC input voltage range of 19-33V

https://www.victronenergy.com/upload/documents/Datasheet-MultiPlus-II-inverter-charger-EN.pdf

You will need to adjust the low voltage cut-off voltage and the settings for charging depending on the datasheet of your batteries.

1629529595115.png (89.1 KiB)

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Modifications Space

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Answer 1 · 2021-08-21T07:55:26Z

kane-1 answered · Aug 21, 2021 at 07:55 AM

Thanks for the answer.

I read in some discussion that the ESS ignores some of the voltage settings, so I wasn’t quite sure. So it is enough if I update the battery settings and the device cut-off limits.

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Paul B commented · Aug 21, 2021 at 08:45 AM

The ess has its own settings so if you change these to something diferant then some of the inverter settings are overriden ie the voltage cutoff settings in the ess, but most of the charge settings are not controlled outside of the multiplus

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Answer 2 · 2021-08-31T19:17:55Z

kane-1 answered · Aug 31, 2021 at 07:17 PM

Thank you. I calculated the voltages from the original values for 11 cells and the system works just as well as before. I also calculated ESS dynamic-cut values for 11 cells.

Although capacity doubled the problem is still low voltage warnings and early alerts. There are as many warnings as before. The alarm starts at 85-80% and continues to 65% until alert + sustain mode is activated. At that time, 174Ah was taken from the batteries.

Just wondering, are the standard dynamic-cut and sustain values too tight for these tubular plate batteries? What values do you recommend?

Hawker perfect plus (3 PzB 225) 2x11cells (22v)

perfect_plus_td_gb.pdf (enersys-hawker.com)

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