nokia battery to a wireless/external charger?
 

Hi!

i am wondering if there is a device (or charger) that turns a spare battery to an external charger? most of external chargers uses non-removable battery, and i have 2 spare BL-5J battery which i dont use very often.

so again, is there any device that drains the juice out of a spare battery to charge another mobile device's battery???

thanks!!! (searched like hell but not enough, and tmo is my last option)