Dual-mode phone (GSM+CDMA)

Yesterday my father has bought me a ZTE H500 for my birthday. This phone is unique coz' it has two slots for SIM card and RUIM card. So it's being more efficient with only brought a dual-phone that contain them instead of two phones that contain separately. However the bad side of this dual-mode phone is the battery will run out very fast coz' it is actually two phones merge in one. Luckily the vendor is good enough to give you a separate battery right out-of-the-box. So if the battery has run out and the separate battery is far from you, pray that's nothing important matters will call you. This dual-mode phone is sold ranging at Rp. 800.000,00 to Rp. 900.000,00 and as far as I know, being the cheapest dual-mode phone in Indonesia.