More Background about Charging Protocols
Charging protocols are important to a good user experience. Apple “i-Device” products are especially fickle with solar charging and battery packs. At Solio we have a special output mode built into our products that makes them backwards compatible with all generations of Apple “i-Devices” while we have a second mode built for the wireless industry (CTIA) standard. Of course the fact that we use a battery as a “buffer” between solar energy input and discharge means that your electronics will always receive a uniform power supply— just the way they like it.
Even more background: When USB was first adopted by the market in 1998, the original specification for power output was only 150mA. As time went on, additional specifications for outputs of 500mA, 900mA and eventually 2A were established to supply power more quickly. Because the same physical connector (USB) is used for all these multiple generations of standards – there also needed to be a way to indicate to the connected device that it can safely draw higher current (or not) — and that was accomplished through use of the data lines of the USB cable. If a device was set to allow the draw of too much current the results could be as simple as the device shutting down, or as disastrous as the device or charger overheating and self destructing.
The real problems came when batteries got bigger and the need for higher output rates evolved quicker than the standards, so manufacturers developed proprietary techniques to communicate the charging requirements to the discharging device. Of course these manufacturer solutions are competing and incompatible with each other and with the Wireless Industry (CTIA) power and charging specifications. So today there is a mess of incompatible gear in the marketplace and consumers are confused. Sometimes the charging experience seems smooth and other times there is a problem or and error message. Most chargers either support one proprietary standard or one CTAI standard but nothing else. Many manufacturers side-step this compatibility issue completely by calling their device “Universal” when all that really means is it will discharge at the lowest rate the target device perceives as safe. This means a charging device that is capable of fully charging connected device’s battery in an hour could actually take 2 hours to charge if the target device doesn’t recognize that it is connected to a compatible high-power charger.
At Solio we are concerned about a good user experience -solar charging provides enough variability— users should not have to worry about the physical connection USB connection being made but the target device not charging correctly. We’ve built in the two main standards for 1AMP output and allow users to switch between them for an optimized charge rate. View our support section for more information about changing discharge modes.