Lenovo T480, internal battery drains before external, destroying hot-swapping capability.

I think anyone who has the same problem as the title of the thread would know what I mean. Otherwise a quick google search will show you a lot of discussons on Lenovo forums and complaints online about it.

Basically the conclusion is that apparently for many users, Lenovo T480 drains its internal battery before its external battery which destroys the battery hot-swapping capability. Many people also mention that the UEFI has been programmed to drain the battery with less wear to be drained first.

Now, I'm not sure how true that is. My 3 cell external battery (let's call it 3cx) for example has 100+ cycle and the 3 cell internal (3ci) has a lot less number cycles. The wear is much higher on 3cx than 3ci but almost all of the time, especially while booted from Windows 10 3cx gets drained first.

Now on the linux side, sometimes 3ci gets drained first. In fact, that happened to me for the first time last week. After charging to full 3cx gets drained first.

According to some people, the battery drain order depends not only on the wear but also on the capacity of the battery. Based on Lenovo Vantage my 3cx has lower capacity than 3ci.

So my 3cx has highest wear, lowest capacity, so my 3ci should always be drained first but this isn't true on Windows 10 anyways. Can someone else confirm this? To me, I've only seen 3ci getting drained once the whole time I've had this machine for. Also does this mean that if I use my 6 cell external (6cx), I will always consistently drain the external battery first?

Also most importantly, has anyone found a fix?

 

it could be your T480 internal backup battery been aged for more than 2yrs of usage that it cannot take charging anymore?

 

It does charge. It seems that on linux side sometimes the internal cell discharges first.