Is it normal that a laptop battery drains when the laptop is off?

Question

I have an HP ProBook 450 G2. Every time I shut down the computer and turn it back on after a day, the battery level decreases by about 5%. I'm sure that the computer is shut down, not in sleep or hibernate. I removed the battery from laptop and after inserting it, the battery percentage does not change. I tried updating the BIOS, disabling wake on LAN in BIOS options, and calibrating the battery several times.

Is this drain normal? If not, is it a hardware failure or can I fix it with software?

Answer 1

The problem may be some hardware drawing power when the laptop is powered down. Common bits of hardware that do this are USB mice and keyboards and in-built wireless network cards.

A few things to check:

1) When powered down, is the mouse still active (light on)?

2) Open Device Manager
* For each hardware listed, open Properties
* Is there a `Power Management` tab?
* If yes, ensure `Allow this device to wake the computer` is NOT selected
* Click Ok (and move onto next hardware entry)

For the 2nd step, there will likely be dozens of hardware entries in Device Manager. Each check takes about 15s, so you'll need to budget about 5 or more minutes...be patient!

Another problem may be the network card itself. By default, modern network cards continue to draw power even when the laptop is "off". Refer to this Superuser question and answer for details.

Update

In Windows 10, you can list devices that can wake the computer (and will therefore draw current) as follows:

* Run a command prompt (with administrative privileges)
* Type "powercfg -devicequery wake_armed" and hit <Enter>

The response should be NONE. If not, find these devices in Device Manager and ensure Allow this device to wake the computer is off.

Answer 2

Remove battery, keep it removed for one day , insert it again and now check your charge percentage. If it is drained, then there is something wrong with battery. If not, then issue is with lap. Check if USB power on when laptop is off option is enabled like @Tom Hundt suggested. Another possible reason can be battery getting short circuited. Get you laptop checked by service center.

Answer 3

Same problem here with an HP-dv6 Laptop. Many users have reported the same problem with laptops from different manufacturers.

On a Lenovo forum, one user pointed to Intel Management Engine. The problem dissapeared when the user disabled such a feature

Many modern laptops include similar hardware (management engine, advanced management, anti-theft technology). This hardware can be powered on even while the laptop has been shut off. IMO, this can be the reason for depleted batteries. The solution should be as easy as disabling these features in the BIOS. Sadly, many manufactures only allow basic BIOS access whereas the advanced settings are hidden (and blocked) to the average user. Some HP laptops fits (mine does) into this category.

Several manufacturers are using insideH2O type BIOS wich have advanced features locked. The user (i.e. the owner of the laptop) is unable to change parameters as UEFI, or AHCI, so... he or she won't even know whether the laptop has some kind of additional hardware intended for management features.

The solution? I think I know the cause, but I have been unable to solve the problem so far.

Answer 4

Suggest you google "laptop battery self discharge" for lots more discussion. (tldr: They always lose a little...)

One issue might be a USB port has power on -- even when off -- for charging phones etc., maybe you can disable that.

An HP user had a discussion at http://pressf1.pcworld.co.nz/showthread.php?95333-HP-laptop-battery-self-discharge-even-when-powered-off-!/page2&s=3340c86eb475bb424dce04f05ba9c9cb

Answer 5

Batteries are strange (and complicated) things. They have more capacity when warmer, because the chemical processes are more efficient.

So, if the battery was measured while the machine was ON, then it has more capacity than the next day, when the battery cools off. Also, the microprocessor in the battery pack estimates the capacity by temperature and voltage. It's not an exact science.

However, while using the battery (the next day), it will warm up again, and recover its capacity. So the 'remaining time' will decrease more slowly at the beginning, while warming.

Li-ion batteries self-discharge, which can be 2 - 3% but per month, not per day. So, if you want to avoid self-discharge, put the battery in the fridge. But then you have less capacity because of the cold, so you have to wait for the warming up... Complicated?