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repro avatar image
repro asked

MPPT 150/45TR tripping inverter with overvoltage

Here is my configuration:

four 175W HQST panels in series (Open-Circuit Voltage (Voc): 24.3V, Optimum Operating Current (Imp), 8.62A), VE MPPT 150/45TR SCC, four 12V LiFePO4 (105Ah) in parallel, Giandel 12V 2200W inverter.

I have this problem that the inverter is constantly tripping on over voltage (16V or higher). The VE 150/45 surges over 16V when cloud cover opens quickly, and the draw on the inverter drops as well. I have set up a "Battery Preset" customized for the batteries and it works fantastic. The inverter manual suggests to not use the inverter if overvoltage shut downs occur. That defeats the purpose of having solar. Any ideas?

Is there any way to limit the power spikes/surges on the controller?

MPPT Controllers
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3 Answers
seb71 avatar image
seb71 answered ·
I have set up a "Battery Preset" customized for the batteries and it works fantastic.

Sounds like you might have Equalization enabled. Otherwise the SmartSolar charger should not get to such high voltage. Or maybe it's defective.


Can you post a screenshot with those battery settings?


Also, those LiFePO4 batteries have some BMS?

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repro avatar image
repro answered ·

356eb5a7-8575-4e40-bb97-455279050e9b.pngScreenshots uploaded. The batteries are Lion Energy UT-1300’s with very good built in BMS.daf6db02-ae70-47c4-b08e-5bdffaf4b9bd.png8814ca5f-c1a5-4c04-b4f1-0998b7cd92b2.png


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seb71 avatar image seb71 commented ·

Does that over voltage issue happens only when the batteries are full or close to full?


I can't see anything in the settings which would explain those 16V.

But the absorption voltage is set at maximum allowed for LiFePO4.

Also I found this here:

Victron inverters charger and charge controllers should be set to 13.9 volts for a 12 volt inverter and 27.8 for 24 volt inverters.

Maybe lower it to 13.9V-14V and see how it goes.


Not a cause of you issue, but your Float voltage is somewhat high. Set it to 13.4V.

You could also enable Tail current.

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repro avatar image repro seb71 commented ·

Yes, it does happen when the batteries are close to full (Absorption phase). I am using the charging voltages that Lion Energy gave me. Actually, they suggest 14.6V for absorption, I never go above 14.4V.

I will lower the absorption setting to 14V and the float to 13.7V and enable tail current. I feel that my batteries will live longer with those settings.

Hey, thanks for the help! I am changing the settings now and will let you know how is goes.

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repro avatar image
repro answered ·

The batteries are 4 Lion Energy UT-1300’s with built in BMS.

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