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wakka421 asked

SmartSolar MPPT 75/10 not charging

I have a SmartSolar MPPT 75/10 controller with a Renogy 100w panel charging my BatteriesPlus X2 Power group 31. Every few days I will see barely any charge for the day. When I check the app, I will see 20v on the panel, and usually just over 12v on the battery, yet 0w from the panel. If I put a load on the battery, and bring it just below 12v, I will start getting a charge. Additionally, if i disconnect the controller from both the panel and the battery, and then reconnect it, it will suddenly start working fine again for a few days.

I am new to solar and completely lost on this. I hope someone can help me out. I attached some screenshots if they help.screenshot-20210701-163853.pngscreenshot-20210701-163937.pngscreenshot-20210701-164046.png

MPPT Controllersbattery charging
screenshot-20210701-163853.png (209.4 KiB)
screenshot-20210701-163937.png (125.8 KiB)
screenshot-20210701-164046.png (131.0 KiB)
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2 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

you need to check the voltage settings for your AGM battery. Float voltage should be somewhere closer to 13.6V and boost / Absorption voltage 13.8 - 14V (but check the manufacturer's data. you may also need 2 panels in series to get the PV Voltage to >5V above the battery voltage for the MPPT to commence charging. remember to keep the open circuit voltage of the modules in series to <75V.

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wakka421 avatar image wakka421 commented ·
Thank you for the ideas. I looked but was having a hard time finding the manufacturers settings for the batteries. I'll call them tomorrow and try this out. Thank you.
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carlrjohnson avatar image
carlrjohnson answered ·

What do you have the dial set at? I believe it comes default for AGM batteries, but check the battery voltages against the table that is provided in the manual.

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