cherry mobile ruby charging problem..plz help
 

If i plug in My cherry mobile ruby icon indicate it charging....but my % getting low..until Shut down. I try also charge my battery on universal charger until its full and insert in my phone all fine..and used it around 4hrs untel reach 15% then i decided to charge it again in her own charger of my cherry mobile ruby... Still icon on battery saying charging but my battary dropping down...
And if i hold usb connector and pushing up charging % added..
Please somebody help me i try to open my device but i dont have idea how to start..
First time of me how to disassble cherry mobile ruby..
If you have some vid or picture how to disassemble my device..
I try already searching on google but i cant find one..