Powering MCU from 48V positive or negative current

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jmzorko
 
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Powering MCU from 48V positive or negative current

Post by jmzorko »

Hello, all ...

I want to make a device, using an MCU like a Feather or Particle Photon that monitors a 48V 5.3kw LFP battery and outputs battery statistics over CANbus. The battery (BigBattery LAMA) has an Anderson connector that is connected to my solar inverter. Since it seems silly to use a small battery to power the MCU when it itself is connected to such a large one, I want to draw the power for the MCU from the LAMA via the Anderson connector and just use a buck converter to go from 48V to 5V or 3.3V.

However, when the battery is being charged by the solar inverter (Sol-Ark 8k in my case), the inverter is feeding current _into_ the LAMA via that same Anderson connector. Since I want to monitor battery stats while discharging _and_ charging, I need the MCU to get power from the Anderson connector whether it's coming from the battery (48V, positive current) or to the battery (48V, negative current). How do I do this?

Regards,

John

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adafruit_support_bill
 
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Re: Powering MCU from 48V positive or negative current

Post by adafruit_support_bill »

Charging does not reverse the polarity - just the direction of current flow to the battery. The Buck converter will still see 48v at the Powerpole connector. And it will divert what it needs from there to power the MCU.

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