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ako avatar image
ako asked

MPPT going into Float too soon

MPPT is a month old and set to use Adaptive Absorption time but going into Float while it and the Shunt are showing to still be taking up to 10 amps when my tail current is set to 1.9 amps . The Shunt is showing around 94-96% SOC and doesn't reach 100% for another 2 or 3 hours once its been down to Tail Current for 5 mins . I believe this Data to be correct .

The Smart Shunt shows my discharge over night is around 10-11% which from all the other indications such as equating to the correct percentage of my Battery Banks capacity , displayed Consumption on VRM ,during non charging times , voltage and past experience which leaves me to think it has to be the MPPT thats not functioning correctly .

Shunt cable is 4 AWG and 60cm long to carry a maximum of 50 amps at 28 volts , all other cables are also short and amply sized , connections are all tight . I have DVCC set to share Temperature , Voltage and Current but I'm wondering if its due to my consumption being to light and Adaptive Absorption is using some other criteria to trigger Float although ..

The other confusing thing is that I understood Float only compensates for natural losses to keep batteries full but I am seeing it actually charging my batteries , should it do that ?

I can post more screenshots of anything that would help identify the problem

MPPT SmartSolar
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klim8skeptic avatar image klim8skeptic ♦ commented ·

I can post more screenshots of anything that would help identify the problem

yes please, for mppt and smartshunt.

dont forget battery type and specs.

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ako avatar image ako klim8skeptic ♦ commented ·

Batteries are 1 year old Trojan AGM ,4 x 392 Amp Hr , C20 is 370 Amp Hr

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3 Answers
Alexandra avatar image
Alexandra answered ·

@AKO

For a full diagnosis you would need to share more. But you are correct shallow DOD will lead to way shorter absorption time due to the adaptive setting choice.

Also described in the mppt manuals.

It float it may be 'putting amps in' but not raising the voltage. Again more information is needed to look into that.

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ako avatar image
ako answered ·

screenshot-2023-03-29-10-42-26-49-30b6efbd53acd6f2.jpgscreenshot-2023-03-29-10-41-31-53-30b6efbd53acd6f2.jpgscreenshot-2023-03-29-12-14-39-56-30b6efbd53acd6f2.jpgscreenshot-2023-03-29-12-33-58-21-30b6efbd53acd6f2.jpgJust noticed MPPT went into Float 5 mins ago so i took some screenshots in the hope it might help , at the time it was 97% but went up to 98% before i was free to take the screenshots , there was actualy 4.6 amps coming in at that time .

screenshot-2023-03-29-12-13-54-24-30b6efbd53acd6f2.jpgscreenshot-2023-03-29-10-42-17-92-30b6efbd53acd6f2.jpg




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ako avatar image
ako answered ·

Batteries are 1 year old Trojan AGM ,4 x 392 Amp Hr , C20 is 370 Amp Hr

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