I downloaded an app Phone INFO which shows a number of stats, particularly "Battery Discharge Cycles". I want to know if this number is being retrieved from the battery (i.e. it's just the number of cycles for the current battery) or the phone (i.e. it's the sum of the cycles across all batteries the phone has contained). In other words, if I insert a brand new battery, should I expect the count to drop to zero?

Context: I have a Samsung S6, which doesn't allow easily changing the battery. I went to a phone repair shop to have the battery replaced. I left it there for the day and did not observe the process of replacement. Now I suspect that I was scammed and the battery has not been changed. I want to confront the shop and use the cycle count (which is still very high) as evidence, so I'm checking my understanding first.

  • After replacing a new battery, you must calibrate it. This link helps you.
    – M. Rostami
    Oct 20, 2019 at 12:14

2 Answers 2


I cannot quote official documentation but I believe that you have not been scammed.

As per the discussion I had with developer of 3C Tool box pro here and the preceeding posts, it is clear that the charge cycle info is stored in the kernel and requires root to access it.

After investigating on a couple of devices, I found some kernel files that can provide the charge counter. On Samsung it is root-only, whereas on Pixel it seems open-bar

On Samsung it could probably load the existing charge counter (if rooted or access allowed) (Post 971)

There is no reason to believe they have modified the kernel files, especially on a Samsung device where rooting trips knox and the customer would be aware of root since some Samsung specific apps wouldn't work. Not worth the cost of a battery replacement.

  • The phone has definitely not been rooted. It was switched off before I left and is encrypted with password protection. I'm accepting this because it seems like you know best regarding my actual question. I'm still skeptical about whether my phone contains a new battery because it still discharges very quickly.
    – Alex Hall
    Nov 5, 2019 at 12:39
  • Thanks for accepting. Regarding quick discharge of new battery , it is entirely possible! Reason: It depends on the date of manufacture of battery . Batteries lose life by just storage. Figure in this answer explains. If the "new" battery is say 2 years old , it is as good as the one you have. That's why it is always better to replace early on
    – beeshyams
    Nov 5, 2019 at 12:46

It seems the issue is that when the battery is replaced, most mom and pop places don’t have the skill or equipment to go in the “root” to reset the counter. It’s akin to not resetting the change oil light on your car. The issue is that some cars use oil life to make other decisions on engine operation, so without resetting the light, performance isn’t fully restored because the computer thinks it’s still old oil and making its decisions based on that. Your battery life, auto shutdown, and battery life remaining display are kind of the same. I bet your phone goes to zero faster than you expect and shuts off, but after leaving it off for a while, you can cut it back on and it’ll show 20-30% or more battery. If so, the thing to do is to keep draining the battery without plugging it in, until after sitting the phone doesn’t even have the juice to try to start, then charge it up to 100, preferably on regular vs fast charge. The life monitor will adjust to the new high and low, and you should have better battery life performance. What’s happened is your phone is basing the full charge and dead capacity off your old battery still, and this process should force it to adapt to your new one.

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