Designing Solar Technology into Mobile Electronics

MotionTouch are often asked about the pros and cons of the design and manufacture of solar panels into handheld devices. As the efficiency of solar panels has increased this has become beneficial even for the most power hungry devices like iPhones (see our case study: Mi-Power).

Solar power offers users the chance to be genuinely mobile for long periods. Users includes:

• Armed forces
• Campers and festival goers
• Personnel worker out doors
• Beach goers

Solar products also offer marketing departments a genuine edge for every day users. Solar is certainly fashionable.

There can also be a big financial saving obtained including a solar panel in your product. Depending on the end Market, products with solar panels fitted can also qualify for duty free status. For mobile phones this can be a huge saving.

When considering the design challenges it is important to take into account the following:

• Solar panels are very robust and if mounted properly will survive very challenging drop and IP rating tests
• The power control circuit needs to carefully manage the charge collected and distributed or it can be wasted.
• LiPo batteries can only safely operate at below 45 celcius
• The design process is fairly straightforward and solar power can be added to most existing products.
• The strength of sunlight varies drastically with season and latitude. This can best be understood by studying the insolation tables published by NASA. http://aom.giss.nasa.gov/srlocat.html

Our products have been used around the world. The most challenging conditions in America, Middle East and Northern Australia have demonstrated that to be truly mobile the products must operate at or above 60 degrees Celsius (easily reached on car dashboards). Meeting this challenge is the most difficult part of the process. There are a number of considerations to address and that’s where the design department really earn their money.