[Q] teclast p79hd 3g battery drain problem need new rom? topic

i bought a teclast p79hd 3g but unfortunately it has a very big problem with battery drainage so much during standby i dont use sim card on it but it says cell standby near 75% battery draining of course the phone is in airplane mode . i want to find new rom for it where can i find this?
plz help me i do many thing to solve this problem but sometimes cell standby , sometimes android system,and so on ... drain the battery so much
for example near 15% in standby the battery will drops.