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teddysx3 avatar image
teddysx3 asked

MPPT 100/50 and Orion charging voltage under 14.4

Hello everyone,

I have a 300ah lithium battery bank. I charge it from shore with a Multiplus 2 3000va at 14.4 volts no problem.


But...when I charge from the Orion 30a or a MPPT 100/50, I get current running but the voltage doesn't rise above 13.5v-13.7v, but the batteries do get charged and are topped to 100% SOC. Is this normalno for both to not be able to produce 14.4v? My Orion is showing my alternator pushing out 13.6v-13.7v and around 300w current. My solar panels are two 320w panels in paralell at 42.5v, 450w current on a sunny day.


I'm under the impresson that lithium needs to be charged at 14.4 in order for the chemestry inside to work, will chargin at a lower wattage still push power into the batteries and how safe is it? and should the Orion and MPPT get up to 14.4 in normal operation?


Thanks all!

MPPT Controllersorion-tr smart
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1 Answer
kevgermany avatar image
kevgermany answered ·

You don't say what the Orion and MPPT charging settings are, but both should be set to the correct settings.

Check the correct battery charge voltages with the supplier/manufacturer, it varies.

It's not clear where the SOC is coming from, but if you start your voltage with fully charged batteries, the chargers may well switch to float voltage and remain there, supplying power to service loads at float voltage.


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teddysx3 avatar image teddysx3 commented ·
Yes, sorry I did not supply the charging setting.


Both Orion and MPPT are set to 14.4 absorbtion, and 13.6 float.


I start charging with Orion and MPPT at around 60-70% SOC, and it looks like they are keeping float voltage at around 13.6-13.7 to charge, but in the MPPT history, I see hours of absorbtion charge, and very little float, which is strange because absorbtion should be at 14.4.

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