If the Disk Utility GUI on OSX doesn’t allow you to format a USB Stick or SD Card with FAT32 the command-line does.
- List the available disks with: “diskutil list”
- Find the device you want to format eg.: “/dev/disk2” and use this device in the next command.
- Format with: “sudo diskutil eraseDisk FAT32 DISKNAME MBRFormat /dev/disk2″
Here is the official Apple way to create a bootable USB stick from a OSX installer: https://support.apple.com/en-us/HT201372
This mobile USB charger called Powertrekk uses a fuel-cell cartridge. It was developed by the swedish company myFc. Inside the cartridge is a coiled flexible foil strip, about as thick as a Band-Aid, that contains the exchange membrane and fuel. The system is supposed to replace common batteries and is able to charge smartphones and other devices that are charged via an USB connector. The Polymerelectrolyte-fuel cell is loaded with disposable tanks so called PowerPukks. Less then 2 Euro each they are plugged into the main unit. They contain Natriumsilizid and are according to myFC non poisonous. The cell is activated when the user fills a small built-in tank with water. Unlike other fuel cells, it requires no pumps, increasing efficiency and reducing weight. After activation it is ready to provide you with 1000 mAh at 5 Volts.
The fuel-cell doesn’t charge devices directly. Instead it transfers its power to an internal 1600 mAh accumulator that is then used to charge external devices. The price will be around 200 Euro.