[ltp] Re: how to trick a W540 or P70 into charging from a 90-110W power supply?

[linux-thinkpad@linux-thinkpad.org]

On Wed, Feb 24, 2016 at 03:45:52PM -0800, Marc MERLIN wrote:
> Both those laptops use a 170W power supply which is freaking huge, and also
> means that I can't use any of the 10+ regular 20V lenovo 90-110W power supplies
> I have at work and at home (AC, DC 12V, and laptop battery packs)
> 
> When I plug any of them into my P70, it will not discharge, but it will not
> charge either.
> Even if I shut down the laptop, or put it to sleep, it will not charge.
> Yet, when I plug it in to keep it alive, it only uses about 25W from my 110W
> power supply, so there is plenty of room to charge the battery, even if not
> at full speed.
> 
> I'm not sure how the laptop detects the fact that I don't have a 170W power
> supply, but I'd love to know a way to trick it into charging from a smaller
> power supply.

Here is the fix:
http://marc.merlins.org/perso/linux/post_2016-02-29_Hacking-a-thinkpad-slim-tip-adapter-to-output-more-than-90W-_required-to-charge-a-Thinkpad-P70_.html

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/                         | PGP 1024R/763BE901