question

mrjj avatar image
mrjj asked

Help needed for correct Lifepo4 battery settings for Multiplus II 48V

There is battery alarm on the screen of Multiplus II GX

According VRM my battery is way above low battery, I measured myself and it was 52.1V while 51.9V shown on the screen of Multiplus. Based on voltage still far away from low battery.

I tried to look earlier questions and noticed that ESS assistent will overrule battery setting in Inverted tab of VEConfigure.

Now how should really set it in order to utilise my battery as much as possible ?

My Redodo battery has been given 47.2V as low battery warning voltage and 43.2V as low shutdown. How do I get those values in use as Inverter tab values are not in used ?

I am a bit confused of used charging modes bulk, absorption and float states which are used in case of lead acid battery.

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My setup:

Multiplus II 48V 3000VA GX

Redodo 25.6V 100Ah x2 = 48V Lifepo4 battery. Recommend charging 0.2C = 20A - 0.5C= 50A. Max 100A

Battery cables are 50mm2 quality copper cables, length only like 1.5metres max.

Here is battery logging from last night. A charging session on the middle starting 2am

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Multiplus-IILithium Battery
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1713855308759.png (55.6 KiB)
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1 Answer
Alexandra avatar image
Alexandra answered ·

@MrJJ

Your low battery alarms are being triggered by the rating values you have set in the ESS assistant not the ones set on the inverter tab.

Adjust those and the warning will go away.

The other option is here in Q5 in the ESS manual.

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mrjj avatar image mrjj commented ·

You mean those C values 0.5C - 0.005C with related voltages. I do not know how to calcuate those voltages....?

Right now discgarge ended to 22% / 51.62

Minimum SOC is in ESS settings 10%. I do not need any reserve for grid failure.

That Q5 stuff,it was by default set to alarm only.
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Alexandra avatar image Alexandra ♦ mrjj commented ·

Just set them all at the low voltage warning the manual wants they can all be the same it is fine. I assume you are cycling anyway?

Your battery also needs a bulk/absorption (same voltage). You can make float what ever you like. For lithium i usually go about 1 to 1.2v lower than abs.

Do you have a balancer between the two batteries?


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