Voltage of small RAK solar panel showing 5.8v on multimeter

I just checked RAK’s little solar panel with a multimeter, and in the late afternoon (16:30) sun the voltage showed as 5.6-5.8v. I haven’t used it yet - I’m concerned about connecting it to a rak19007 with a 4631, as the datasheet specifies up to 5.5v.

Am I safe using this with my wisblock? Thank you

Good night,

Take a look in this post: low grounding current regulator

They have a good conversation about how the regulator is designed.


Same as we answered in Concerns with 150x100x45mm solar enclosure voltage

You are good to use it. There is a Zener diode on the base board to limit the voltage. The 5.5V in the documentation is just an “over-protective” limit.
But it should be not more than 7V or the Zener diode might get to its limits.

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Thank you, testing now!

The VBUS_D rail is clamped on the RAK19007 at 5.6V by Zener D3.
I presume that in the case of a small PV panel, D3 can load the panel down under overvoltage conditions and dissipate the excess voltage as heat without issues.