Wednesday, December 04, 2013

Solar Fantasies

This is a warning article about Solar Powered battery chargers.   I was alerted to CNET et al proclamations about a design project which aims to recharge an iPhone from solar energy stored from panels on the side of sunglasses.

Did the designer Mr/Ms K do any testing on the feasibility of this idea?

Now our Story
When Marcus and Agata attempted the GR20 hike in Corsica we wanted to take our technology with us.

You can read about our preparations,  what to take, and a daily account of our progress.

Start Here:

And the Daily activities page

Ultimately we failed to made the tough 20 day hike in our allotted 10 days due to equipment failure.  But not of the Electronic kind.

What About Solar Charging then?
As part of the preparation we investigated, by actually buying and testing prior and also taking the best one on the trip, solar powered chargers to an Apple iPhone

We bought 

Several quite large panels which included a quite heavy rechargeable battery

We also bought a bare panel  (no battery).

And a hand cranked dynamo

We tested by placing the panels on our balcony in Switzerland, altitude 600 metres up, strong sunshine

The largest and lightest unit was the pure solar panel.  It did begin to charge the iPhone, just.   But after multiple hours it had gained less than 10% in direct sunlight.

The Battery backed panel, did recharge the iPhone from the stored battery, but leaving these devices outside all day in Sunshine, was not enough to do ANY significant recharging.

Also the Battery backed panels were not waterproof and one got corroded due to water/ moisture, and stopped working in my tests.

Further, the pure panel would have had security issues since leaving it out connected to a phone in a mountain chalet could easily lead to phone theft.

The dynamo too was a failure.  Despite being quite tiring to crank, charging the phone past a few percent was a Herculean effort.

In Effect
I found the solar charges totally ineffective/ useless.

You are better carrying a set of dry cells with an an adapter 
So what does work [say on multi day mountain hike/trip]?

  • FANTASY mode on: The best would be a butler /  support teamRather like an inconspicuous camera crew that follows celebrities though the jungle.   Fully equipped with generators and supplies.    Yes, only for the few.

  • A rechargeable battery bank.  As you can see the one above is 216 grams and 12000mAh.   On a hike, if you can plan your route past a refuge/ restaurant [every few days] which can offer you electric power, you are sorted.

  • Dry Cell Charger. Works great, however used batteries have to be kept to end of Hike, for environmental disposal, meaning your load never gets lighter!
  • Spare Batteries!  Because iPhone charging did not work we bought several spare camera batteries and used them for > 1 week of photography.   The iPhones were kept fully charged, and ready for an emergency phone calls only.  Worked a treat!

BUT.  Please don't take my word for it.    Buy a solar panel with rechargeable battery.    Then, starting from a fully exhausted battery try recharging it from the sun and charging your dead SmartPhone.   I'd be very happy to be proved wrong.

Like I said before, any dimwit can come up with an idea, it is handed over to the averagely paid Engineers to try and get it to work. Thanks then.

To prove the point here are 5, impractical, non cost effective, or non working solar designs that would be just great ...

  1. Solar panels on the roof of an electric car, to recharge its batteries  (not just power the electrics!)
  2. Solar panels on the front forks and/or back bicycle stays to power its lights
  3. Curved Solar panels covering your bicycle helmet to charge your iPhone
  4. Translucent Solar Panels integrated into all external household windows to provide electricity
  5. Solar panels on a watchstrap to power a SmartWatch

Solar Panel Sunglasses - Just a concept you idiots!
Solar Power Sunglasses - yeah right!
Upto 30000mAh Power Bank
Pure Solar Panel
3.5W (max) Panel no Battery