Fix: Lenovo ThinkPad fully recharges battery after restart despite charge thresholds

This is a 'how to' for battery threshold setting on Lenovo laptops with Windows 8 and 10 systems when your battery recharges fully after the system restart.

I've recently updated my ancient Lenovo laptop to Windows 8.  To prolong lifespan of my battery I had to setup again the charge thresholds to not start charging the battery sooner then bellow 5% and stop up at 100% using PowerManager 6.36 with PowerManager driver.

However, after system restart the battery started to charge fully every time - a way to significantly shorten it's lifespan.

To fix it I did some search.  First, install also install ThinkPad Settings Dependency for Windows 10. Then there are forum posts how to fix charge thresholds manually (doesn't work after update to Windows 10) and one more also for the Windows 10 issue.

Changing ChargeStartControl, ChargeStartPercentage, ChargeStopControl, ChargeStopPercentage registry keys under HKEY_LOCAL_MACHINE\SOFTWARE\Lenovo\PWRMGRV\Data didn't help.

The correct registry settings are located elsewhere:

HKEY_CURRENT_USER\Software\Lenovo\PWRMGRV\Data\<your battery serial number>\

If missing, create it.  The serial number should be found under PWRMGRV\ConfKeys\Data\ as a registry subdirectory.

You may need to manually create any missing DWORD values, in my case those are (in hex):
ChargeStartControl: 0x00000001
ChargeStartPercentage: 0x00000004
ChargeStopControl: 0x00000001
ChargeStopPercentage: 0x00000064

After you do the changes, restart your machine.

These settings then produce the following status that persists after system restart:

lenovo charge thresholds power manager settings

2 thoughts on “Fix: Lenovo ThinkPad fully recharges battery after restart despite charge thresholds

  1. I am running Windows 10 and this process did not quite work for me. I am with you up until the part about the 11 digit alphanum code. I don't have such a folder in my registry. Under Data, I have "ExtremeBatteryLife," "Gadget," and "RapidResume." I've tried adding the DWORD values in all of them and still have yet to figure out something that works. Do you have any ideas? Thanks.

    1. After Windows 10 update to 1511 (the November update) you can no longer use the Power Manager software at all. However, its driver still digs and is present after a clean Windows 10 install. Note that the following steps has been tested only on such clean installation. No warranty for any updated system.

      Also install ThinkPad Settings Dependency for Windows 10 to make the following work.

      The thresholds are located at HKEY_LOCAL_MACHINE\SOFTWARE\Lenovo\PWRMGRV\Data HKEY_LOCAL_MACHINE\SOFTWARE\Lenovo\PWRMGRV\Data\<your battery serial number>. There you find the four magic keys: ChargeStartControl, ChargeStartPercentage, ChargeStopControl and ChargeStopPercentage. Just set those and restart the machine.

      If this still doesn't work, check this forum post.

      I also think to force the data to be stored to the battery you have to change the ChargeStopPercentage value. I have first set the stop threshold, that worked very well for me. Then I wanted to set the start threshold as well, but the battery was still charging when between start and stop percentage. Then it occurred to me to change the stop percentage once more and then immediately restart. Since that moment everything seems to work well for me! Suggested values are: start 25% (for convenience may be up to 50% or even 60% as well), stop at 80%. This saves the battery very well. On the other hand, for 10 years I was charging the battery to 100% and never started to charge it bellow I think 4%. It still holds for around 2 hours when on 75%! If reformatted, I think 3 hours could well be reached when charged to 100% - after 10 years!

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