In early January 2012, I began thoroughly testing the Pocket Panel: 6 Watt Portable Solar USB Phone Charger and the Cinch Power: CP505S Power Pack (USB Battery). These two products team up to make a compact, lightweight, portable power solution for USB powered devices such as cell phones, GPSes, digital cameras, bluetooth headsets, games, PDAs, MP3/MP4 players or small LED lamps. After a review of the individual components, I’ll summarize some quick system tests.
Pocket Panel: 6 Watt Portable Solar USB Phone Charger
The PocketPanel photovoltaic solar charger is rated at 6 Watts and 1.2 Amps. Reviews on the company’s web site suggest a typical full sun current around 0.9 Amps which suffices for many typical cell phones. In peak sunlight, the array produces enough power to charge a typical load device while actively using it. Modern smart phones require significant charging current, particularly at first, when significantly discharged. In use, the four 3″ x 5.5″ PV panels fold out to about 21.5″ x 7″; four corner grommets with 1/4″ holes provide flexible attachment or tie-down possibilities to maximize solar exposure. A velcro closure simplifies transport, and the unit folds to 7″ x 4.5″ x 1.25″ approximately. The high-efficiency mono-crystalline (17% efficient) require about half the size of earlier poly-crystalline designs and also deliver a higher percentage of rated power over a longer lifetime. (Wikipedia has an in-depth article on photovoltaic technologies, efficiencies, the history of solar cells, etc. They are laminated to a rugged fiberglass substrate, which mitigates some of the weight and fragility of glass. The weather-resistant unit weighs 0.83 pounds. The output is a standard (female) USB port making interconnection easy and versatile. Combined with the adapters in the Cinch Power CP505S, a wide variety of devices can be charged.
Cinch Power: CP505S Power Pack (USB Battery)
The Cinch Power CP505S Power Pack is high capacity, USB-connected battery system with multiple connection adaptors. The power capacity is rated at 5000 mAh (milliAmpHours at 3.7Volts). Output voltage and current are rated at 5.4VDC and 950mA, respectively, with a 500 charging cycle rated lifetime. This unit easily fits in a shirt or pants pocket, at 3.9″ x 2.8″ x 0.7″ It’s lightweight Lithium-polymer cell design brings it’s heft to a mere 5.1 ounces. Simple operation consists of bringing power in (e.g. via a USB-fitted solar charger) using the supplied USB to DC cable. The cable has a convenient self-retracting cord, collapsing to under 5″ and expanding to about 30″. The 3-level power indicator system (Low <20%, Med 20-80%, High >80%) indicates amount of stored charge via 3 LEDs. The On/Off toggle switches output power to the USB connector. A “Use” LED is lit when power is being supplied from the battery. When charged, the charging cable becomes the output cable by using the USB output connector, which then interfaces with a variety of supplied adaptors. Adaptors include: Sony Ericsson-K750, Mini USB/Motorola V3, iPod/iPhone, Micro USB, and Nokia-DC 2.0; this should allow a generous variety of Apple, Blackberry, Nokia, Samsung, Sony, MP3, MP4, etc. devices access to the battery power. The device features over-current and over-charge/discharge protection. It shuts off automatically when the connected device completes charging. An optional AC power supply is available as a backup for extended cloudy weather.
Testing of Paired Products
For pocket transport, the panel array will probably fit best in a coat pocket, whereas the battery (smaller) can easily fit in a typical shirt or pants pocket. The rugged PV array works nicely in a south-facing window, with the attached battery charging next to it on a windowsill. I initially started charging the battery with the PV array around noon on a Friday in January at about 6600′ elevation. After an overcast and snowy Saturday, the full charge completed mid-morning on Sunday. The combo of panel, battery and adapter works well. The blue “Use” LED on the battery blinks to indicate power delivery. The charged battery powered my iPhone (normal sporadic usage for me) on this single charge for about a week. I then fully recharged the battery using the PV system which took about another day. A Vococal 3-LED adjustable clip-on reading lamp with a USB connector made a good constant load test in addition to my iPhone. Running constantly, this bright (more-than-adequate) 3-LED reading lamp ran for about 32 hours continuously.
A full five months later (after a full re-charge), the battery pack had 2 LEDs (somewhere between 20-80% charge) remaining, so the standby leakage current is fairly low. All in all, about the only minor drawback might be the suitability of this system for more extreme weather environments. Other portable PV systems (such as the Joos Orange Solar Charger) offer a bit more ruggedness for severe environments, but this combination is likely to be a good solar solution for many remote, backup and portable applications.
More information about the three referenced products is on their respective web sites: Pocket Panel, Cinch Power, and Vococal.
– L.K.O. (SurvivalBlog’s Central Rockies Regional Editor)