Time for a creative Sunday post.
Now some people cook.
Some people create.
I love doing science experiments at home and proving that something works or doesn't work.
A New Solar Panel
Now the panel was marketed as a 30W solar Panel which is exactly what I need to charge up my power banks or enough to fast charge my cellphones. But will the solar panel do what it claims?
Now to make it simple I think the company is flat out lying in their 30W claim but for $16 HBD I thought I would try it.
Why do I think they are lying?
The panel has dimensions of 12.5cm x 26.5cm
Total size of the panel in sqcm : 331sqcm or 0.0331sqm (square meter)
What does that mean?
Well, on earth at peak sunlight at the best conditions the sun provides about 1000W per square meter. That means that at 0.0331sqm * 1000 w/sqm = 33.1 Watts.
Under ideal sunlight the panel does receive just over 30W of power.
However, it is a Microcrystaline solar panel and that type of solar panel is typically about 15% efficient. Instead of providing 33W it should be providing about 5W.
So the question remains:
Will this USB port output 5V * 6amps which would be fast charging speed.
Or
Will this USB port output 5V *1amp which is old school slower charger speed.
How did I check it out?
Well. For one day I tried to charge up an old small cellphone. For two days I tried to charge up a new model android tablet. For three days I tried to charge up a 100Ah power bank. Each day had full sunshine and the solar panel was left to charge the device from 10am until 4pm.
First up:
Small, old style cellphone.
Now this phone has just been hanging around unused and unloved. What loss if it doesn't work?
I hooked it up to a proven charger or 5min so it showed 2% battery charge. Then onto the solar charger it went.
After 6 hours of solar charge.
The battery was flat dead. Didn't even have the 2% any more.
It seems that the voltage from the solar panel wasn't stable enough for this old phone to figure out the charging.
RESULT: Absolutely useless for this phone
Next up : Android Tablet
This tablet started with 65% battery and its battery is fairly large at 5000mah.
After the first day the battery had charged to 84% and after the second I had 100% charge. I guess the newer battery management system or power system was able to handle what the solar panel put out. However, 35% of a 5000mah battery is not a lot of power put into the battery. 5Ah * 5V =25Wh battery * .35 = about 8 watts added to the battery.
8 Watts over a 12 hour period is less than 1 Watt per hour.
Pretty Sad.
Result: Charged the tablet but very slowly
Next up was the larger power bank.
Now this one is rated as a 100Wh battery. If the panel was indeed a 30W panel it should charge the battery in under 4 hours.
I drained the battery down to very low (showed 20% power). Then I gave it a chance to charge up over 18 hours. Now the charging light was on for those 18 hours which was promising. However, after all those hours charging the battery only went from 1 bar (20%) to 2 bars (40%). 20% gain after 3 days means 20W after 18 hours of charging. Just over 1 Watt of power added per hour.
Result: Extremely slow charging of the power bank
This solar panel is getting returned.
In it's defence I never expected the 30W it said it output. I was hoping maybe 6W which is more realistic. Then after factoring in losses due to heat, losses due to charging and losses due to self discharge I was hoping maybe I would get 3-4W power per hour. 18hrs * 4W/hr....80W of charge.
IF it had charged the power bank to 3 or 4 bars I would have been pleased that it was useful. Not as advertised but at least useful.
As it turned out.
- Not as advertised
- Not good enough to charge the power bank.
- Not good enough to charge up an old phone.
But it was able to charge up a tablet....very slowly.....which at least was something.
However, not enough of a something for me to want to keep it.
End Result:
While on paper it seems like it would be very useful in reality it wasn't nearly as useful.
Thanks for reading
and that's my creative Sunday post :)