[Solar Phone Teardown] Sharp Debuts Solar-powered Handset [Part 1]

Jun 24, 2009 18:55 Nikkei Electronics Teardown Squad

The “Solar Phone SH002.” A sticker on the solar cell module reads “cautionary instruction on solar charging.”

The solar cell module without the sticker

On the back side of the SH002, too, there are many cautionary instructions.

An environmentally-friendly mobile phone debuted in Japan, which is now enjoying an “eco boom.” It is Sharp Corp’s “Solar Phone SH002″ released by KDDI Corp as one of its summer 2009 models of the au brand mobile phones.

The SH002 is equipped with a solar cell module on the back of its chassis. The solar cell module can be used as an auxiliary power source when the remaining battery level is low or zero. Though Samsung Electronics Co Ltd and LG Electronics Inc announced handsets with similar concepts at Mobile World Congress 2009, which took place in February 2009, Sharp is the first company that released such a product in Japan.

According to KDDI, the official release date of the SH002 is June 4, 2009, but the date differs depending on region. Just in case, we checked with the nearest outlet store for au handsets and received an answer that the SH002 will be launched in Tokyo on June 5 but only nine units (three units for each of three colors) will be available at the shop.

Therefore, we waited in line at the shop before hours on the release date and purchased the SH002. We obtained it not for personal use, of course, but for reporting the usability and the mounting technology used for the solar cell module to our readers.

[Solar Phone Teardown] Charging Performance Tested [Part 2]

Jun 25, 2009 17:30 Nikkei Electronics Teardown Squad

The Solar Phone SH002

Our test was conducted on a sunny day.

We started charging the battery when the remaining battery power was zero. The icon of “optimal charging” was shown on the electronic paper.

The angle of the handset to the sun was changed so that it received less light. The icon of “charging” appeared.

In the shade, the icon of “solar power unavailable” was shown.

After 40 minutes of charging, the icon of “one-minute talk time” was seen.

After 60 minutes of charging, three-minute talk time became available.

After 85 minutes of charging, the icon of “five-minute talk time” appeared.

Continued from [Solar Phone Teardown] Sharp Debuts Solar-powered Handset [Part 1]

Nikkei Electronics Teardown Squad started to examine the performance of the solar cell module, which is mounted on the rear chassis of the Solar Phone SH002 as its main feature.

According to KDDI, when charged for about 10 minutes in fine weather, the mobile phone provides approximately one minute of voice call or two hours of standby time (See related article). Therefore, we charged the handset by using the solar cell module before disassembling it.

We began charging the battery at noon June 7, 2009. Though some clouds were seen in the sky, it was nice and fine.

As for the evaluation method for the solar cell module, the SH002 has a function to show information on the status of charging on its 1.1-inch black-and-white electronic paper mounted on the rear chassis. When the module is being used, its charging efficiency is shown in four levels, “optimal charging,” “charging,” “charging stopped” and “solar power unavailable.”

When the power is off, the SH002 indicates an estimate of available talk time up to five minutes. So, we started charging the battery when the remaining battery power was zero and stopped it when an icon appeared to indicate that five-minute or more talk time is available. And we measured the time it took.

First, we exposed the handset to sunlight. Because it was a sunny day, the icon of “optimal charging” was shown on the electronic paper. On the seal attached to the solar cell module, there were messages such as “Do not leave it in high-temperature places like in a car. It could lead to heat generation, ignition, deformation and breakdown.”

Though we believe that the layout was sufficient for the experiment, it might not meet recommended conditions. In fact, when the angle of the module to the sun was changed, the icons of “charging” and “solar power unavailable” appeared.

In the experiment, the icon indicating one-minute talk time was not displayed even after 10 minutes of charging. In the end, it took about 40 minutes for one-minute talk time, 60 minutes for three-minute talk time and 85 minutes for five-minute talk time.

In other words, to have talk time of one minute, it took several times longer than 10 minutes, the charging time Sharp announced. Considering the light intensity and the angle to the sun, the results might be reasonable. In fact, KDDI and Sharp define the solar cell module as an auxiliary power source. The module will be useful when it is not possible to use an AC adapter to charge the handset, for example, outdoors.

We finished checking the charging function of the solar cell module and started to tear down the chassis.