MPPT for Basic RAK4631 Meshtastic Kit for LoRa

WisBlock
1

Hi everyone,

This is my first message here.
I’m still quite new to RAK WisBlock, so I’d like to clarify one detail. Since my RAK19007 Base Board doesn’t have an MPPT controller onboard, what’s the best way to charge a battery from a solar panel?

For example, I have this solar panel from AliExpress:
Waterproof Solar Panel 10W 3W (?!) 5V 100x100mm

image
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and simple LiPo battery - MakerFocus 4pcs 3.7V 3000mAh Lithium Polymer Rechargeable Battery 1S

My question is: can I connect the panel directly to the Base Board so it charges the battery, or is it better to use a separate MPPT like one of these:
mini MPPT Solar Charge Controller 4.2V/
or
CN3791 MPPT Adjustable Solar Charger
(though it seems this one would work better with a 6V solar panel)

Am I understanding this correctly? What would be the better approach?
Also, any advice on best practices for using solar power to charge the battery would be really helpful.

Thanks in advance!

2

Welcome to RAK forum @d00m178 ,

The built-in charger of the baseboard is limited to around 500mA. It also has no MPPT feature so not best in terms of efficiency.

If cost and space is not an issue, I will personally go for an external one. You can efficiently use sun energy and have higher charging capacity.

Just disconnect the battery to the board if you are going to connect it to USB. I have no idea what will happen to your battery if it will be charged both by your external one and built-in in wisblock baseboard.

Nevertheless, you still have to consider if you really need a bigger power from the sun. This will depend on your use case and how much current your full circuit needs.