I remembered last night that I had solar panel in my scrap box. The size was perfect for Jolla and a quick test proved that it can be used to charge Jolla too:

- voltage is about 6 V (measured with multimeter)
- panel outputs 40-80 mA under a lamp (measured with multimeter)

I haven't seen sun in a month or so here in Finland so the test was performed under 70 W halogen, distance ~10 cm.



More pictures:

http://relativity.fi/jolla_solar_toh/

Today I modeled new other half for the panel and printed the new model. The panel fits nicely. I dit not take yet pictures from the inside, but I soldered some wire to the panel outputs and glued wires so that they are in contact with Jolla power pogo pins.

UPDATE: Jolla's CSD tool shows charging current of -10 mA (at winter in Finland). This means the panel outputs about 100-110 mA at winter in Finland (the idle discharge current is about 100 mA). There's still room for 60-70 mA more, but this can be tested here when the sun is shining a bit higher at summer.

Under the 70W lamp CSD tool shows +50-60 mA, so the panel is giving about 50 mA out but the battery is still discharging. The phone still says that charger is connected.
UPDATE END

I have to test the Solar Half more, but it indeed seems to be working rather nicely

EDIT: .stl file available here: https://github.com/skvark/TheOtherHa...esolarhalf.stl
EDIT2: I misinterpreted the CSD tool. Yes, the phone says it's charging and yes, the CSD tool says "Charging" but under a lamp the panel is just limiting the disharge current. If the battery is actually getting more juice, the current is shown as negative value. However, the original 70-100 mA is still realistic.

wow amazing other-half

I imagine your 70W lamp is really lower than the direct sun exposition ?

What a coincidence that your solar panel from your scrap box was a perfect fit for Jolla

I'd love to see something like this commercialized.

Say...how much did you pay for that solar panel? (just a rough guess, I understand if you can't remember exactly)

Thanks in advance.

~Chinoman10.

I'd imagine so. Direct sun exposure is about 1kW per square metre. At high noon, with the receiver exactly perpendicular to the incoming sunlight.

By my VERY approximate calculations, his solar panel received about 5W from his 70W lamp. Most of it in the wrong wavelenght. So getting 360-480mW out of it (6V x 60-80mA) is actually not too bad a result.

Next Jolla phone should have audios tech on the touch screen. That would eliminate need for a solar other half.

I bought the panel from Adafruit (if I remember right) over a year ago. And yes, it was perfect

I think it was 10 USD. Panel: http://www.parallax.com/product/750-00030

So it outputs in direct sunlight max. ~167 mA.

Try to contact with some Solar Panel Factories to send you some test samples in the same size but with higher efficiency panels with specs such us 6V - 3W.
I already use 6V - 2W Solar Panel for my mobile phone Nokia 1020 (130mm*71mm).
I measure in direct sunlight at 14:00 about 220mAh.
Cost me 25 euros.

hmm.. seems that this is available in many places, though parallax is out of stock. e.g. Mouser.. Need to get one

just google "Solar Panel 6V @ 1W, 125 x 63 mm"

so, no components between the panel and the phone? so the phone has regulator that limits current for preserving 5v?

Looking at what rainisto said in the other thread about wireless chargers ( http://talk.maemo.org/showpost.php?p...2&postcount=42 ) a 'dumb' 5V source should be the best option.