I am using samsung galaxy duous s 7582 about 2 years and I will tell you that this is a hanging phone and its speed after one year become very bad. it has 3.8 v lion battery / 5.70 wh and its backup is very bad it is empty after 5 hours so it is not good backup. it has 5 mg pix. camera and its video quality is good and its sound quality is good and its market price upto 9500 but according to price this product is not good .
If we have downloaded some apps in this phone than its speed become very slow and its then its performance is so bad .
its design is normal . it is not a user friendly phone if the use want to download some app in this phone.
thank you.