ESS not drawing from batteries and keeps them 100% charged

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josmeijer asked Feb 12, '23

ESS not drawing from batteries and keeps them 100% charged

In the past (with to my best knowledge the same settings) power was drawn from the batteries till SOC reached its lower setpoint. Either the "hard" setpoint without, or the dynamic with "battery life".

For a considerable time, the batteries keep charging from the grid day and night and SOC more-or-less stays on 100%.

I tried multiple times to reset the parameters, updated firmware, reprogrammed everything from scratch but SOC is stubbornly staying at 100%

What else can I do to get things back to the wanted state of uncharging at night and rescharging (if solar) at daytime?

SOC

nobat.jpg (119.0 KiB)

fullcharge.jpg (43.3 KiB)

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Modifications Space

Node Red Space

Answer 1 · 2023-02-12T09:33:35Z

sean answered · Feb 12, 2023 at 09:33 AM

Go to settings/ESS and confirm what mode is set

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josmeijer commented · Feb 12, 2023 at 10:14 AM

Optimized (with battery life). I tried without too for a while. Same result.

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screenshot-20230212-110428-nlvictronenergy.jpg (328.0 KiB)

Answer 2 · 2023-02-12T11:05:57Z

nickdb answered · Feb 12, 2023 at 11:05 AM

Perhaps some more detail. What batteries?

Have you checked the BMS is configured in the GX system setup as the reference?

Is it sending parameters and details to the GX -> check the battery tab in the GX?

Details will show if charge/discharge is being blocked.

Is DVCC enabled?

If you drop grid supply does ESS start functioning ie charging/discharging?

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Answer 3 · 2023-02-13T08:22:22Z

josmeijer answered · Feb 13, 2023 at 08:22 AM

I replaced the screenshot by a last-year overview that clearly shows that since july last year the battery stopped being involved in my power consumption.

I have flooded lead-acid cells so no BMS is involved. Further I never changed anything in the hardware setup.

I tried enabling or disabling DVCC without noticable differences.

If I drop grid supply the inverter jumps in. (I usually read about power outages in our neighbourhood in the paper some days later :-)

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nickdb ♦♦ commented · Feb 13, 2023 at 10:23 AM

Hmmm. On the remote console, does it ever report an ESS state/error message?

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josmeijer nickdb ♦♦ commented · Mar 02, 2023 at 03:32 AM

yes. I should have remembered that I disabled Low Battery alarms as it reported low battery at inconvenient moments. (without a really low battery voltage)

But now, as I look through the error list, there is an impressive listing of battery low alarms that urges me to start checking on a bad cell.

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josmeijer josmeijer commented · Mar 02, 2023 at 03:47 AM

So, after checking on some cells (not all, as the tip of my multimeter cord snaped off ) my next question is: how can the battery state report 100% as I measure a cell voltage of approx. 1,6 v and a total voltage of +/- 40 volts if I turn the charger off??

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tom w josmeijer commented · Mar 02, 2023 at 08:05 AM

You are using "dump" batteries so the SOC is calculated based on the battery voltage and charge current. The calculation is correct because as soon as the charger is turn on the cut off voltage is triggered because your dead battery is drawing no current. So for the charger the SOC is 100%, but the amp hours of your battery are almost zero.

BTW: Discharging lead acid batteries regularly to 50% will decrease the capacity very fast.

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josmeijer tom w commented · Mar 05, 2023 at 07:01 AM

I used similar setups on our barge for over 40 years and I can state that daily discharging tubular cells to 50% can make them last (without considerable capacity loss) for 15 years or over. I dumped my last set because the connections became unreliable but the capacity was still over 80% compared to new.

Furthermore the ESS "optimize with battery life" will automatically elevate the minimum SOC to a higher value than 50% if the algorithm thinks this will improve life expectancy.

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Answer 4 · 2023-03-25T12:50:54Z

josmeijer answered · Mar 25, 2023 at 12:50 PM

So,

conclusion:

The automatic filling system I got for free with the purchase of the batteries somehow failed and the batteries were completely boiled dry, in spite of my regularly connecting the reservoir with the water supply.

So refilled them with 60-odd liters of water and at first it stayed water, (sw 1.00) but a day later the batteries started boiling like hell, filling the shed with breath-taking toxic vapors while I desperately and in vain looked for a way to stop the charging process (which is non-existent on the solar charger).

The only way to stop it, seemed to be, disconnecting the solar panels which didn't look like a good idea, regarding the amounts of hydrogen gas that was produced.

Even switching off the easy solar seemed too risky (a spark is a spark).

I could in the menu set the charging current limit of the multi to zero and at least cut the current in half and I waited patiently for the sun to set, (at a safe distance from the shed :-)

Apparently some kind of miracle occurred. as the batteries started discharging and I had power all night without any grid usage. Next morning they were still al 68% according to the multi's SOC and now they are recharging when the sun appears, at a rather normal pace, 78% while I write this.

But nothing was wrong with the easy-solar

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