Battery life estimates wrong

Question

I have a Lenovo IdealPad and was reading a couple other forum questions about their laptops having battery estimate problems. These ranged from a loss of capacity after being off over night, such as mine losing over 15% even as the laptop was shut down overnight. To a rapid drop which serious affects the estimated time left of a charge. I mean for example if using my laptop and it estimates my life as say 60% which translates to 3 hours 40 minutes but then 15 minutes later I am at 50% and 2 1/2 hours left? Doing the same tasks and haven't changed brightness or anything? 

This makes the battery estimates pretty much useless and how can I go from 87% capacity when I shut down my laptop to 70% capacity in the AM when I boot up? How can I loose over 15% capacity when the PC is off? Either some of us have some serious parasitic drains on batteries and/or we have some serious issues with Windows being able to determine battery capacity. I've used laptops for years and for the most part battery life estimates have always been pretty stable and accurate. But lately I have noticed that many laptops only show percentage left and not time left by default. Is this trying to conceal a inaccurate system? When I am charging my battery the estimates to full charge seem very accurate. So why are discharges so bad, that we now resort to percentages rather then time ? 

[Moved from: Windows / Windows 10 / Performance & system failures]

Answer 1

Have you ever wondered about the life of your battery? The most probable cause of this issue is a damaged battery. Try using your laptop for 2 straight hours starting from 100% capacity. If it goes down to 20% or below, your battery is already degrading. It is not the system, its your battery.

Answer 2

Actually not all Windows 10 device has fast startup enabled. If you are using UEFI, your fast startup is enabled by default but if you're using Legacy, you can not enable fast startup. I guess you just really need to keep your laptop plugged in at night.

Answer 3

Got Fall Creator 1709 and all updates and Lenovo driver updates. Did try turning off Fast Startup but while this might have stopped the battery drain because after four hours I had no battery loss. The boot up times increased significantly which I now understand why Microsoft enables Fast Startup by default. I guess I will put up with the battery drain, or make sure my laptop is plugged in at night. It wouldn't bother me so much, but my laptop has a rather small capacity battery to begin with being its a cheap model. So any loss overnight is enhanced over a device with say 10 hour capacity. Oh well, something new learned today about Windows 10.

Answer 4

Is your PC up-to-date? I believe this could be fixed by getting the latest Windows update. I guess MS already addressed this issue a long time ago since many people are complaining about it.

Answer 5

Battery is in new laptop so I don't think its battery. I used a battery condition application which confirmed battery is at spec capacity. I begin this inquiry when other people in forums complained about new laptops that had similar issues. Can't believe they all had bad batteries. Fast Startup seems plausible given how it works. But it's interesting that even if its not a Windows issue, that it cannot correctly give a user a relatively accurate battery life report. I've had in the past used Mac's and even Linux desktop OS that gave better more accurate estimates. What good is a battery level status if it doesn't work?