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iman yazdansepas avatar image
iman yazdansepas asked

MPPT 75/15 Load Management with Discharged Battery and PV Connection

Hello,

I recently purchased the MPPT 75/15 for one of our products. I have a question regarding its operation. I've noticed that the module cuts off the load when the solar (PV) is connected, and the battery is discharged. Is there a mode or configuration setting that allows the PV to directly power the load while simultaneously charging the battery?


Thank you

MPPT SmartSolar
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2 Answers
Justin Cook avatar image
Justin Cook answered ·

Load output is powered from battery, not PV, but the load output behavior is highly configurable in the unit using VictronConnect - you may find that tweaking the voltage cutoff settings gets you closer to your desired functionality.

The load output configuration section of the user manual: https://www.victronenergy.com/media/pg/Manual_SmartSolar_MPPT_75-10_up_to_100-20/en/configuration-and-settings.html#UUID-e66362d1-a266-4b2d-4b64-2c478629c072

It sounds like the heart of the issue is that you need more battery capacity (or more power in re-charging) to accommodate your loads though.

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iman yazdansepas answered ·

Dear @Justin Cook,

Thank you for the quick reply.

I went to the load output configuration and set my controller to "Always On." I expected that when the battery is low, the controller would allow the PV voltage to directly power the load. However, this is not happening. Instead, the voltage to the load fluctuates during charging.

Am I missing something in the configuration, or is it indeed not possible for the PV voltage to directly power the load, as you mentioned?

Thank you for your assistance.

Best regards,

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Justin Cook avatar image Justin Cook ♦♦ commented ·
PV voltage cannot power your load. PV voltage is converted to battery charging voltage by the MPPT, and then charges the battery. The Load ports are connected to the Battery ports, so when voltage on the battery ports is high enough, the Load port will be powered. When charging, that power is in effect being provided by solar, but when your battery is severely depleted it will require some time of recharging before voltage on the Battery ports is high enough for your Load ports to become powered again.
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iman yazdansepas avatar image iman yazdansepas Justin Cook ♦♦ commented ·

Thank you so much.

Just to confirm, if I need to run my load directly from the input voltage, I would need to design my own circuitry to bypass the MPPT, correct?

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