I have recently brought the ijoy zenith 3 vape and it came with 2 ijoy 20700 batteries but when I put them into the vape and try to charge it thru the vape cause I didn't have a battery charger handy and just wanted to try it but I left it for about 2 -3 hours and it didn't charge, so I thought that maybe it didn't charge cause I left it on so I turned it on and then charged it for another 2 hours and still nothing any tips?