Question battery full charged capacity decreased after a calibration cycle

[apples42]

hello everyone. I purchased a dell latitude 7490 some days ago in used condition, it got a F3YGT(60wh) battery that at the time of purchase was showing 52wh(87%) full charged capacity in windows battery report, but from that day on I never fully calibrated it once therefore sometimes weird issues like jump from 20% to 7% in around 3mins in an instant jump, sometime it charges to 95% after 10mins straight to 100% in one instant jump which it should not be doing since charge after 70s or 80s is relatively slow and time taking...searched around a bit and found I need to calibrate the battery which i did yesterday charged the laptop to 100%(honestly it was at 95% but after 2 or 3 mins in one instant jump reached 100%) same when unplugged the charger from there after keeping it for another 10mins when it was at 100% it jumped back to 95% in 5mins or so, after that it continued normally decrementing one at at time I kept it going unti it got to 10% and then straight to 5% in a jump, it then turned off automatically at maybe 5% but still I restarted it and went to bios and let it sit there for another 5mins until it fully drained out and was not longer turning on, then i left it for around 7 or 8 hours, now plugged in back with charger(65w) and during charging i got the battery report its now saying it has full charged capacity of 48,328 mWh instead of 52wh why is that reduction? pls somebody help

 

[helpstar]

it´s getting old, how old is the laptop?

might be faulty battery
battery readings are not that precise
background activity can drain battery as well while only sitting/idling

How much time do you usually have from "fully" charged to empty/shutting down windows ?
while it was new, the battery would withstand about 8 hours in normal office/wlan surfing activities.
So now it that it´s a bit older it should be about @ about 5 to 7 hours

check for updates:
gpu
chipset
acpi
battery driver
BIOS of the laptop

 

[apples42]

it´s getting old, how old is the laptop?

might be faulty battery
battery readings are not that precise
background activity can drain battery as well while only sitting/idling

How much time do you usually have from "fully" charged to empty/shutting down windows ?
while it was new, the battery would withstand about 8 hours in normal office/wlan surfing activities.
So now it that it´s a bit older it should be about @ about 5 to 7 hours

check for updates:
gpu
chipset
acpi
battery driver
BIOS of the laptop

If I remember correctly it gave me around 5hr 19min of continuous multimedia use(played a long video with 45-50% brighness) before completely shutting down during battery drain, drivers etc are updated, laptop was released in 2018 battery does not seem faulty since backup seems good but only thing thats weird is that drop of wh

 

[helpstar]

also try these steps, if not done yet:
https://www.dell.com/community/en/c...0-dell-latitude-7490/647fa319f4ccf8a8de8d885d