New Victron LFP installation constant switch between bulk and absorption

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eliott asked Mar 22, '19

New Victron LFP installation constant switch between bulk and absorption

Hi!

I have a new LFP system with with Quattro 48/5000/70-2x100 and 4*Smart Lfp 25,6 200Ah. What I see when charging is the system only switches to absorption for a short time and immediately back to bulk, never to float. Is this normal or expected? The charger voltages are the default from the Quattro. Thanks

Lithium Battery

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boekel ♦ commented · Mar 22, 2019 at 12:04 PM

-are these the only components in the system?

-what did you set in the Quattro settings? (screenshots of VE-configure)

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Answer 1 · 2019-03-22T12:09:54Z

mihair answered · Mar 22, 2019 at 12:09 PM

From where are the batteries charged, from grid?

When this behaviour happen, constantly switching from Bulk to Absorption,, are the battery almost full (over 90%SOC) ?

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eliott commented · Mar 22, 2019 at 03:11 PM

Yes, almost full, charging from grid, limited to 6A@220V.

I see no alarms online in VRM

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Answer 2 · 2019-03-22T14:11:47Z

eliott answered · Mar 22, 2019 at 02:11 PM

Yes, this is how the voltages and current look like.

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Answer 3 · 2019-03-22T15:09:31Z

eliott answered · Mar 22, 2019 at 03:09 PM

Yes, almost full, charging from grid, limited to 6A@220V.

I see no alarms online in VRM

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Answer 4 · 2019-03-22T15:17:53Z

boekel answered · Mar 22, 2019 at 03:17 PM

-are these the only components in the system?

-what did you set in the Quattro settings? (screenshots of VE-configure)

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eliott commented · Mar 22, 2019 at 04:04 PM

Components: Quattro, CCGX, BMV, VE.BUS BMS, Color Control GX, Digital Multi.

Charger setup:

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boekel ♦ eliott commented · Mar 22, 2019 at 04:51 PM

ok, next thing to check: BMS

I -think- your charge voltage is so high your BMS stops the charging due to one cell being charged too high.

I don't know if you can see separate cell-voltages? this might give a clue.

Other way to try: lower absorbtion voltage to 56 V and see if this helps.

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eliott boekel ♦ commented · Mar 22, 2019 at 04:56 PM

Ok, thanks, I'll try that. I have no access to the cell data, I am remote now. But I can upload the config remotely I think. Should the new value be only temporary until the cells get balanced and should I increase it back?

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eliott boekel ♦ commented · Mar 22, 2019 at 05:23 PM

ok, it went into absorption. Do you think that the cells will equalise and I can turn it back to the recommended values?

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boekel ♦ eliott commented · Mar 22, 2019 at 05:31 PM

I don't know, I personally like to not charge above 3,45V per cell (55,2V) but I don't know if there is a minimum voltage to be reached to let balancing start (should be in the manual)

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eliott boekel ♦ commented · Mar 22, 2019 at 05:48 PM

Actually, tha's why I ask. According to the manual, it should be 56V, so 56V is the minimum required. That's why I was asking if one should try to go a bit above.
Batteries must be regularly (at least once every month) charged to 14V (max. 14,4V) in order to fully balance the cells. Two or four batteries in series should be charged regularly to 28V resp. 56V

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boekel ♦ eliott commented · Mar 22, 2019 at 06:25 PM

Ok, then 56V is fine for now I'd say :)

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