The issue is caused by fracturing of the Battery FPC connector, which results in the phone not receiving data from the battery. Li-Ion batteries in modern smart phones don’t just have a ‘positive’ and ‘negative’ terminal like your more simple batteries. They also transmit data to the phone. Which consists of telling the phone the temperature of the battery, the amount of cycles its completed, its current voltage, and more. However when this data isn’t getting transmitted to the phone – yes there still is power to the phone – however the phone cant determine what % the battery is. The battery connector on the battery side, doesn’t have much solder on it, and fractures quite easily after a drop.

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