it was not a problem with the charger to begin with. you got 2 probably because the seller included the original charger that comes with a US set (100-120v).

the 2nd charger is probably a 3rd party (220-240v compatible) that works with the local electrical voltage output. if u plug in the US charger into our local electrical outlet it will most likely "fry" the charger thus rendering it useless thereon.