iPhone 6(S)/Plus Battery sudden drop under 50%

[emembee]

My 6s is just over 2 years old. It shows capacity of either 87 or 81% in Coconut Battery and Mac Tech tool Pro. It seems to be fine when it is charged and discharges normally to about 50% but then suddenly drops to 30% or lower and I cannot see why. Battery health is normal and I cleanup or close all running apps too, brightness is fairly low.
Any ideas why it would suddenly drop or is it time to upgrade, I expect the answer is the latter ... unless I get battery replaced but not sure it is now worth doing it as Apple have a better than expected trade in offer at present.

 

[mrex]

My 6s is just over 2 years old. It shows capacity of either 87 or 81% in Coconut Battery and Mac Tech tool Pro. It seems to be fine when it is charged and discharges normally to about 50% but then suddenly drops to 30% or lower and I cannot see why. Battery health is normal and I cleanup or close all running apps too, brightness is fairly low.
Any ideas why it would suddenly drop or is it time to upgrade, I expect the answer is the latter ... unless I get battery replaced but not sure it is now worth doing it as Apple have a better than expected trade in offer at present.

you just need to google and see that many iphones have this issue. some batteries are replaced by the warranty program - check apple battery replacement program if your phone model is under the program, you get it for free. if it is not, then you still have time to get it replaced for $29 (or something similar lower price) before the year ends. On 1.1.19 the price goes back to the normal.

 

[Newtons Apple]

My 6s is just over 2 years old. It shows capacity of either 87 or 81% in Coconut Battery and Mac Tech tool Pro. It seems to be fine when it is charged and discharges normally to about 50% but then suddenly drops to 30% or lower and I cannot see why. Battery health is normal and I cleanup or close all running apps too, brightness is fairly low.
Any ideas why it would suddenly drop or is it time to upgrade, I expect the answer is the latter ... unless I get battery replaced but not sure it is now worth doing it as Apple have a better than expected trade in offer at present.

You problems are almost certainly due to a bad battery. Beware of the trade in quote as it can change once they get your phone.

 

[BugeyeSTI]

you just need to google and see that many iphones have this issue. some batteries are replaced by the warranty program - check apple battery replacement program if your phone model is under the program, you get it for free. if it is not, then you still have time to get it replaced for $29 (or something similar lower price) before the year ends. On 1.1.19 the price goes back to the normal.

$29 battery replacement ends 12/31/2018:
https://support.apple.com/iphone/repair/battery-power
https://forums.macrumors.com/thread...program-is-set-to-end-on-december-31.2157943/

 

[emembee]

Thanks for responses and links. It would be good to have an Apple hardware test that I could run to check. Geekbench 4 has a drain function I could try. Meanwhile will see if I can get a slot with Genius Bar though it looks like I won’t make the cheaper price in time.

 

[akash.nu]

Thanks for responses and links. It would be good to have an Apple hardware test that I could run to check. Geekbench 4 has a drain function I could try. Meanwhile will see if I can get a slot with Genius Bar though it looks like I won’t make the cheaper price in time.

Other than coconuts battery, none of the apps can measure battery performance reliably. At best it’s always a guesstimate. As everyone else suggested, the sudden drop is due to low voltage in the battery because it can’t hold on to the charge anymore. You need to get it replaced. Do not waste time trying multiple softwares that can’t tell you anything better. Just go to an apple store and get it replaced. As everyone else pointed out, you’ve literally got 2 days to avail the discounted price.