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chebanov avatar image
chebanov asked

PV Solar Power on MPPT Drops from MAX to 0

I use MultiPlus II 48/1600/20, CCGX, MPPT Solar Charger 100/20 and third party BMS 48V-100Ah LiFePo battery. During the sunny day, the Solar Power drops from max to 0 few times a minute. Inverter started to discharge the battery until the PV Power raise. System configured with ESS and "Keep batteries charged" mode. Without DVCC. The differents between dashboard screenshots is actually few seconds. Could anyone help me?

Dashboard1.png

Dashboard2.png

PV Yield.png

MPPT ControllersESSlow power
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dashboard2.png (52.2 KiB)
pv-yield.png (69.0 KiB)
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2 Answers
chebanov avatar image
chebanov answered ·

I'm suppose that problem was solved. My consumption was equal 260W but the Solar Power on peak reached 800W. And with feed-in disable - the excess energy had nowhere to go. When I increase the charge current on MPPT to 7A (7*48=336W), which is enough to cover the consumption - the problem disappeared.

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nickdb avatar image
nickdb answered ·

Hi, there isn't enough to go on.

Pull vrm charts (or use victron connect) to show what PV voltage is vs battery voltage.

Panel voltage could be dipping beneath the battery +6V threshold and moving to an off state.

Pull charts that show the BMS CVL and CCL. The BMS may be limiting the MPPT via DVCC.

Or you could have a bad connection, wiring or panel.

Any number of reasons.

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chebanov avatar image chebanov commented ·

battery-vs-pv.pngBMS is not connected to the system. It's only built in battery.

DVCC is disabled.

I see that MPPT state occurs Fault frequently. How can I find out why?

mppt-state.png

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mppt-state.png (7.5 KiB)
nickdb avatar image nickdb ♦♦ chebanov commented ·

Connect to the mppt via bluetooth and victron connect. It should record the fault.

It might also be in event/alarm logs on VRM.

Should also be in the cerbo, under the mppt's entry - daily history records the last error state.

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chebanov avatar image chebanov nickdb ♦♦ commented ·

alarm-logs.png

I saw this error before. But it's not as often as the problem happened.

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nickdb avatar image nickdb ♦♦ chebanov commented ·
Your panels are exceeding the voltage limit of the mppt.

Check the specs (Voc) and make sure you allow for peaks due to cooler temps.

You are at risk of smoking that mppt.

Again, victron connect will show the peaks recorded, or the daily history tab of the mppt on the GX.

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