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dqiu5 asked

MPPT 75/15 Battery Undercharge Protection?

Hello,

I'm currently working on a device using the MPPT 75/15 solar charger to charge a 12V lead acid battery from a 24V solar panel. The location that I am testing this device snows a lot in the winter and there have been several days where the snow completely covered the solar panel. Thus, the battery was not being charged. I have the load configuration set up so that current to the load gets cut off when the battery is at 11.8V. Usually when the solar panel is exposed to sun, this would be approximately the lowest the battery voltage could get. However, I noticed when the snow completely blocked the solar panel from charging the battery, the battery voltage decreased to almost 9V. In order to protect the battery undercharge, I was wondering if the MPPT 75/15 has some feature built in so that it doesn't continue to consume the battery voltage until the solar panel can charge the battery (and power the MPPT 75/15) again?

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1 Answer
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onyx2435 answered ·

Hi. No ! The mppt 75/15 doesn’t have the option like a smart battery protect . You need to buy it separate and then set it to 11.8v to cut off. I also have same 75/15 smart with a battery protect smart and it’s setup to shut down at 11.8v . But if your load is directly from mppt then I think you can set up there to shut down at 11.8v ( not 100% sure because my load is from battery not from mppt )

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