bounty - solar powered adapter

[ryanckulp]

(for existing TRMNL developers, join the Discord and visit the #ideas > solar powered TRMNL thread)

requirements

1. should not require opening up / modding device
2. USB-C adapter to solar power

scope

• build working prototype that provides enough power for a 0% battery to produce screens every 15 mins
• provide BOM / purchase list / docs for anyone to build this themselves (+ we may also assemble some as an accessory)
• design or source 2x mounting options that cover indoor vs outdoor use (ex: kickstand vs wall plate + swivel toward sun)

compensation

$699

next steps

reply to claim, then report progress every 5 days to prevent release back to the community.

[yankobogdan]

I've ordered parts
It will take longer than 5 days to arrive
So, I don't want to claim it yet

[ruohki]

I have portable panels and a brick but no sun T_T

[mintdotco]

would something like this work?
https://www.alibaba.com/product-detail/Type-C-USB-Output-6v-5w_1601193133849.html
or
https://www.alibaba.com/product-detail/7W-Solar-Security-Camera-Charr-5V_1601350601791.html?selectedCarrierCode=SEMI_MANAGED_ECONOMIC@@ECONOMY

[yankobogdan]

would something like this work? https://www.alibaba.com/product-detail/Type-C-USB-Output-6v-5w_1601193133849.html or https://www.alibaba.com/product-detail/7W-Solar-Security-Camera-Charr-5V_1601350601791.html?selectedCarrierCode=SEMI_MANAGED_ECONOMIC@@ECONOMY

I've ordered smth very similar to test
I am almost sure it will work under decent sun, but not sure for the room conditions
So it's would be a subject of testing

[ruohki]

What spec is the original charger?

6V 5W 1.2A from the Panel is a weird Powerspec. I would assume 5V or 9V so that USB-C power is probably just VCC and GND rather than properly implemented USB-C PD.

[yankobogdan]

We need a stable 5V on the charger output
Even a low current like 0.1A would work
A cheap charger wouldn't be efficient, but it could be sufficient

[NetForces]

I have one of these here: https://www.spypoint.com/en/products/lithium-battery-solar-panel-5w/splb-10

Would work great. It has a direct 5V USB output.

[yankobogdan]

I have one of these here: https://www.spypoint.com/en/products/lithium-battery-solar-panel-5w/splb-10

Would work great. It has a direct 5V USB output.

Agree, but quite expensive
It has 7500mA battery capacity itself

[NetForces]

There is also Voltaic: https://voltaicsystems.com/small-solar-panels/ that has great options.

[deisterhold]

Is this available to claim?

I've been working on a couple different options.

I've ordered this panel and so far it's worked to charge the device. I'd recommend this for an outdoor solution.

As for the indoor option, I'm waiting on this panel to arrive and then I will come up with some sort of mounting option. Thinking either a 3d printed option or a suction cup option.

@ryanckulp has there been any decisions on how to block the charging led from showing through the front of the device?

[jonm01]

[jonm01]

If you are looking for a external solution. I think SwitchBot Solar Panel for Curtain 3 should work. Its cheap and simple.
https://www.reichelt.com/de/en/shop/product/switchbot_solar_panel_for_curtain_3-387369

[yankobogdan]

@jonm01

Looks very decent
Good job!

Do you have any performance measurements?
To better understand how much energy it's collecting

Also, I see that you are using another battery, which seems to have less capacity
Is there a purpose for that?

[jonm01]

@yankobogdan

The solar panel charges the original terminal battery from 81% to 100% in one afternoon. My setup receives about 2 hours of direct sunlight most days. However, I have noticed higher battery drain at night, likely due to the charging circuit consuming some power when there’s no sunlight. This could be further optimized. Additionally, the panel I have isn’t the most efficient.

Update: Now, I have two devices, and there was almost no direct sun last week but still the solar one has more charge remaining. I need at least few months to see if its worth it. Maybe I don't need to charge ever again.

[ryanckulp]

catching up here, thank you @jonm01 for the MVP and photos, seems like a neat solution. are you open to submitting a guide for someone to mod their board like yours, or do you instead defer to the linked SwitchBolt option?

and @deisterhold , how did your panel experiments turn out? happy to make this a win-win for both of you. i apologize for the massive delay.