I am designing an off grid system for developing countries for charging cellular phone, tablets pad and notebook computers. Design aim is to use low cost, simple, mature (slightly older) and mass-manufactured technologies. Your idea and contribution are mostly welcome.
I plan to use ready made modules from ebay, etc.
Is mono crystal solar panel better for this task? What point to take care on choosing PV panel and controller? 100W panel seem mainstream size.
For notebook charging, I plan to use off the shell, 12V boost to 19 V, simple boost converter, 6 to 8A. Many excellent information in this post. Why do many laptops run on 19 volts?
To what extend is 19V 'standardized'? Some posts mentioned some brands use special '3 wires' charger that communicate between notebook PC and charger, so that non brand charger will not work.
To what extend is the power connector size standardized? Do I need to get those multiple size adapter kit? https://en.wikipedia.org/wiki/DC_connector
For charging of 'slightly older' phone (USB 2, 5V, 0.5A), I plan to use an off the shelf 12 to 5V USB simple buck converter module.
How about those latest phone and notebook that use USB 3.1, USB C, Quick Charge, Power Delivery mode, that are higher current, voltage or both? Are they backward compatible? What will they do when connected to a simple (no intelligent communication) buck converter supplying 5V?
For use in developing countries, there is no need to chase the cutting edge. However, if it is low cost and easy to do, what are the prospect of something better than the basic "USB 2 at 5V 0.5A"?