LeoRex
Retired Moderator
Huawei used crap batteries; pure and simple. I have two 6Ps, and they're both the same. Inexcusable for 16 month batteries.
They didn't use cheap batteries. What they DID do is make a decision to have the cell be 3450mah. OEMs the size of Huawei work with battery suppliers to 'pair' the battery to their phone... i.e. phone's power system is designed to work hand in hand with the parameters of the battery's charging circuitry.
Now, the one thing I've noticed is that the 6P charges to some 4.4V... that is really high for a LiPO based cell. High voltages cause stress on these batteries, and that stress, over time, will slowly reduce the operational capacity of the battery. PLUS... with a peak voltage that high, if you leave a fully charged phone on the charger for extended periods of time, this increases the amount of time the battery is at that high voltage... again, this will cause it to degrade quicker.
Now, Huawei isn't alone in doing this... a bunch of phone manufacturers are going this route. By increasing the max voltage, they can put in a higher rated capacity battery without putting in a physically larger battery. That's why you see a lot of people asking why the battery on their new phone is shot so quickly and how older phones didn't have the problem.