I completed the battery replacement on my i-phone 6 yesterday. I only had problems with the adhesive, but I worked through it. I’ve checked almost all the phone functions and everything is working. The new battery had a 50% charge. I let the battery run down to less than 8% charge and hooked up the charger. I let it charge to 100%. That was about 10:00pm. When I got up this morning the phone was completely discharged. I charged it again to 100%. It’s now almost 3:00pm and my i-phone is down to 46%. I received one phone phone call of only 1 min. in duration. other than that I’ve not used the phone at all. The i-phone is not holding a charge.