SOC has reached "Bulk finished" level but it didn't go through Absorbtion and Float phase

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dcsonka asked Apr 5, '23

SOC has reached "Bulk finished" level but it didn't go through Absorbtion and Float phase

Hi,

I have a 5kWp 3phase (3x Multi+2 3k 48V) system with 4x3.5kWh Pylontech freshly installed and I noticed that when the SOC reached 95%, then it remained there for 90min and then it increased to 96% and stayed there unchanged. I expected, that after reaching the end of bulk state, it will jump to Absorption and reaches 100%.

I also noticed that the battery voltage is over the absorption limit of 52V, yet the chargers stopped charging the battery (even with full sunshine).

I read it from older questions that in such cases I should increase the voltages in the MPPT, but it doesnt change anything, because the MPPT settings are overridden by the BMS settings of the battery (MPPTs are BMS controlled).

But instead the solar chargers stopped charging the battery at this stage. I have the following settings.

I attached my settings, maybe you can help me to fix this issue.

Thanks

Dezso

battery charging SOC

1680702850965.png (260.2 KiB)

1680703051157.png (26.1 KiB)

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dcsonka commented · Apr 05, 2023 at 02:07 PM

Here are some more screenshots. No sign of Absorbtion. Maybe my values are too low?

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1680703631310.png (123.7 KiB)

dcsonka commented · Apr 05, 2023 at 02:09 PM

Seems that one of the screenshots were deleted

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1680703725553.png (232.8 KiB)

dcsonka commented · Apr 05, 2023 at 02:26 PM

Ok, one must have a little bit of patience, the yellow LED on the MPPT and M+2 lit up and in parallel the SOC is 99%. I suppose, it will reach 100% and go to float state.

The only thing that I don't get is whether it changed because I set the absorb/float values on the MPPT to the same like in VE.Configure, or it just changed because it really reached the absorption level. I will need to spend more time on htis.

Thank you

Dezs

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Answer 1 · 2023-04-05T14:30:53Z

nickdb answered · Apr 05, 2023 at 02:30 PM

This is completely normal and documented in the pylon/victron install guide.

Just need to RTM.

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Alexandra ♦ commented · Apr 07, 2023 at 06:23 PM

@dcsonka

The Pylontec seem to run themselves a little differently to what you are expecting.

No, the mppt will not show absorption stages, or float.

If you are reaching target voltages,with not alarms, then all is well.

I also hardly see 100% and if it does, it is for a short time.

As @nickdb mentioned....

It is in the documentation here.

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dcsonka Alexandra ♦ commented · Apr 07, 2023 at 09:32 PM

Thnx Alexandra, now things are getting clearer :)

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