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anna-zaleski asked

MPPT Solar setting help

In my campervan I have a dual leisure battery (Yussa L36 95h) and a 180w solar panel with a MMPT 100/20 with a 180w solar panel which is showing as off in the day and normally only works early in the morning or late at night, but only shows as bulk rather than float or absorption. I can use my fridge, lights etc in the day and my battery will go low as 12.0 but the solar panel doesn't kick in the day, so I have to turn things off, but by morning I seem to be fully charged again! My battery levels can drop from 12.7 to 12 within seconds then come back up as soon as I turn the loads off. Any ideas very welcome.img-6764.jpgimage3.pngimage0.jpeg

MPPT SmartSolar
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nesswill avatar image nesswill commented ·

On the first picture i don't see a BATT - connection to the MPPT do you have better pictures of the connection's please as it could just be hidden.

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anna-zaleski avatar image anna-zaleski nesswill commented ·
Many thanks for your reply. I will get a better photo tomorrow for you.
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anna-zaleski avatar image anna-zaleski commented ·

img-6779.pngImage CaptionI put my compressor fridge this morning when my panels were working as it was a sunny day. By 8.30am they had gone off and my battery went down to 11.9

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3 Answers
Alexandra avatar image
Alexandra answered ·

@Anna Zaleski

Your panel voltage needs to be at keast 5v above battery voltage to start working.

It seems your panel does not quite get you there. You would be better off with either another panel or a pwm charge controller.

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kevgermany answered ·

Can you give us that graph for a full 24 hours, and add battery voltage. I'd like to see the daytime performance of the panels.

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anna-zaleski avatar image anna-zaleski commented ·
Thanks for your reply, I will do that tomorrow for you :-) Thanks for your help.
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anna-zaleski answered ·

Hi

Here is the last 24 hours. Many thanks

img-6778.png


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kevgermany avatar image kevgermany ♦♦ commented ·
Thanks. That confirms @Alexandra suspicions. Might be better to add an extra identical panel if you can. Or use PWM as already suggested.

Quite surprising that there's such a short daylight period. Or is there a lot of shading?


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anna-zaleski avatar image anna-zaleski kevgermany ♦♦ commented ·
Hi thanks, no shade and south facing drive. So my solar panel is not big enough for my MMPT ? Many thanks
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kevgermany avatar image kevgermany ♦♦ anna-zaleski commented ·
Look at voltage, adding a second identical panel in series, not parallel, will make a big difference.
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