I i thing try use apps batteryxl feat wall usb charger with 100v-240v 500mA...i feel better b4 using charger w/out batteryxl apps..
I was charged 40‰ to full just 2 hours..that mean 30%=1 hour..for 20% to full around 5 hours or less
I bought a charger adapter (my usb lead from the tablet fits into it) sold as a generic replacement for an Ipad. I has 5.1v and 2.1A output and charges it in something like 3 or 4 hours. Charging from a regular USB port was incredibly slow; this has solved my problem!
The problems I experienced were:
The standard delivered charger had an adapter for Europe and this did not connected properly to the main charger. So I had to repair it straight from the box.
2nd prob is that the plug to connect to the Ainol 7 Fire tablet is very specific. So don't buy any 5V 1000 to 2000mah charger because it will not fit. I have an external battery with a lot of connectors, but nothing fits the 7 Fire !