I am trying to power my spark core from a portable USB battery source. I am powering it through the VIN pin which is wired to a female USB connector. When I plug the spark into a standard USB charger (such as my iPhone wall charger) it powers up fine. However when I plug it into anything that is battery powered such as:
- Solar iPhone Charger: http://www.ebay.com.au/itm/like/161644097420?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=107&chn=ps
- Adafruti Solar Charger: https://learn.adafruit.com/usb-dc-and-solar-lipoly-charger
- Freetronics USB Booster: http://www.freetronics.com.au/collections/modules/products/usb-boost-5v-usb-power-supply#.VQ-rPI6UenM
It does not come on? Do I need to tie the USB connectors data lines together of something to get these to work?