@Oditius, I mean a mobile wireless charger with inbuilt battery.
And btw, lumia 1520 doesnt need those stuff you hook to the back of your phone. And i think nokia created special wireless charging case for all its phones.
That one you have to plug in, but the White one has a 10400 battery. But no good for me, since I have PMA charging and not Qi....
Wireless Power Rechargeable External Battery for Samsung Galaxy and Lumia - White