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SCK2.1: Solar power

I’m looking for more informations about the battery and a solar panel. All the documentation available seems to be outdated.

  • what are the specs for a solar panel?
  • how to connect the solar panel?

thanks for your help!
Best Regards from switzerland!
martin

Looking for the same

I am looking at the following but no ideas if it is suitable.

I am currently using a similar solar usb charger on my setup.

It does work in that the battery charges quite quickly in bright conditions but when it is not charging the unit seems to drain power. I would say on average the battery lasts about 50% less with this attached. In the middle of summer this was fine but even now barely past the equinox I get more and more device off line warnings as the battery runs out.

Admittedly the panel is facing due east and is mounted to a window so the angle is not ideal but even so I would not expect a solar charger to draw power when not charging.

Here’s a picture of my current setup:

David
https://draksck.1mb.site

Thank you for showing your setup and pointing to the draining issue.

I’m now thinking about a solar panel together with a small charge controller like this one: https://www.solarversand.de/solar-laderegler-12v-10a/ (sorry german only). This would also allow the connection of a big lead battery to ensure operation of the kit in winter times.

My colleague @victor is currently running different experiments to find the best solar power setup, including tuning the firmware

We hope we can release our recommendations as part of the documentation soon!

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@pral2a, please do, I am looking forward to that :slight_smile: .

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Hi,

Yes, we are working on that and I hope in a couple of weeks we will have some documentation and a firmware version with some tweaks specifically for solar panel setup (like the drain issue that you mention).
I’ll keep you posted!

Cheers.
Victor

2 Likes

Hi everyone,

We keep working on the tests!

We’ll publish some conclusions soon!

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Any news on this? I could not find anything for SCK 2.1 but need to do a demo with solar powered kits

Hey did you have any results there yet?

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“soon”??? Is this topic dead?

Hey!

Actually not, we have finished a design using a P.V. panel from VoltaicSystems and this MPTT, with an additional battery for backup (same as the one in the kit).

With all this COVID-19 lockdown we haven’t been able to put it all in the documentation. At the moment this is not a pack, but it will probably be at some point.
@victor can give a bit more information about the results with other panels?

2 Likes

Hey, some new info on the firmware side!

Here is a commit related to power management.
Now the kit always sleep between readings even if it is connected via USB like with a solar panel.
This will reduce a lot power consumption while using a solar panel.
After user event (button click, configuration or sd card events) the kit waits for some time (configurable) and then it goes to sleep only waking up to get readings or send data to the platform.

This commit will be included in the next release, if you are in a hurry you can compile the code yourself!

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its already working on the bench - sorry terrace :slight_smile:

Wow! That looks good!

Do you have an enclosure or are you planning on building one? Let us know!
Also, if you want to put the MPTT in a box, this is what we currently use (designs coming soon): https://es.rs-online.com/web/p/products/2663120/

Keep us posted on your progress!

I’m trying to put everthing in this case: https://github.com/fablabbcn/smartcitizen-enclosures/tree/master/SmartCitizen%20Outdoor%20Cases%20V2.0-2.1/3D%20Printed%20Prototype

Maybe I need to make the cover a little larger to have enough space for the MPTT and the second battery. If that doens’t work; I’m going to use an external case like the one you provided.

btw my setup is using the DFRobot MPPT, an additional 3000mA 18650 Li-Ion (the round one) and 6V (thats fine with the MPPT) 0.83A monocrystaline Solar Module

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Completely new to Solar panels,
Would this be suitable (with some type of charging controller) to power my SCK2.1? - https://www.sunstore.co.uk/product/6v-10w-monocrystalline-solar-panel/

If not can someone tell me what I should be looking for on the panel specs.

Thanks

Andy

Mine has half the power (5W). If you use a 10W Panel, make shure your MPPT can handle the current.

Hi Martin,

Thanks for the quick response, the more I google solar panels and MPPT’s the more I am understanding, and I am now trying to find a UK supplier for both units so I dont have to pay stupid delivery charges!!

Andy