question

wbs avatar image
wbs asked

MPPT 100/50 stopped charging

It went into float although batteries at 95%. Turned on equalization and still no charge current. It shows charge current dropping to 0 but also a weird increase in battery voltage for a few minutes after the charge current went to 0. Settings are: absorption:14.4V,float: 13.8V, equaliz.: 16.2V. My other 2 MPPTs have been working fine for over a year.

I’d appreciate your opinion and help.





MPPT SmartSolar
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2 Answers
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klim8skeptic answered ·

@WBS Without knowing what your batteries are, what you are using to determine SOC, or the mppt history,

no advice can be given.

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wbs answered ·

These are LedAcid batteries, 2140 Amphrs. SOC is as shown by the emeter which served me well for over 10 years. Unfortunately I can't load the graphs from the Victron app


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klim8skeptic avatar image klim8skeptic ♦ commented ·
@WBS It looks like the mppt thinks it has fully charged the battery.

If the battery has reached the absorption voltage, and the mppt has held it there for an appropriate time before going to float, then the battery is likely fully charged.

That would assume that there is no voltage drop between the mppt and battery, and whether the other mppt's have the same settings (??).


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wbs avatar image wbs klim8skeptic ♦ commented ·
Hi, I appreciate your patience in responding. First: the other MPPTs are not relevant as they are charging another battery bank (Lithium). Second: there is no reason for the MPPT to think the batteries are full, in the past month it always charged to 100% before going into float. Even at 100% it continued doing bulk for a few hours before going into float. There is no voltage drop between the MPPT and the batteries, I am using thick wires.

I have many years of experience with a variety of chargers and batteries and this behaviour is definitely not normal.

Is there any specific test you can think of that I should do next time I am at that house?

Thanks for your thoughts.

PS: I tried everything to include pictures in this thread but the insert image or upload file always gives me the same error: "Parsing response failed"

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