[ltp] Battery draining ove 16W cause battery death in 1 or 2 month

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Sat, 11 Jul 2009 08:53:15 -0300

On Sat, 11 Jul 2009, wbonx wrote:
> So I bought a new battery, the normal (small not extended), at the start
> under windows the life was about 2.45h and under linux 1.15h.
> After one month of usage only under linux the life was degraded, under
> windws  1.15h and under linux 40minutes.

You like to do full-charge+deep-drain cycles?  If you do that to a Li-ION,
you kill it in 6 months.

> I tried to use the TP_smapi modules on the new battery to prevent damages to
> battery customizing the charge, but no way, now is almost unusable.

Deep drains (drop battery below 30%) are FAR more damaging than full
charges.  Maybe that's not your problem, but the other complains of this
type I have seen either involved a lot of deep drains, or crappy battery
cells and packs bought from third-party dealers in the Internet.

> The battery is designed to give no more then 14W, is it possible that the

Yes, high drain might cause more wear, but not to the degree you see AFAIK.
That said, you probably should pay a visit to thinkwiki.org, and read up
everything you can.  Then, fix whatever configuration problem you have that
causes that high a drain...

> problem under linux is that there are not IBM drivers that manage the power
> drain preventing it to excheed the 14W limit of the battery?

There are Linux drivers that manage *most* of what IBM drivers can, and the
BIOS does a lot of it by itself (which reminds me: upgrade to the latest
BIOS if you want any sort of support from the kernel people like me).  This
doesn't mean these drivers are working fine on your setup, though.

Also, for Linux it is important that you disable in BIOS stuff you don't
need often (serial ports, IR, modem, whatever).  Linux is not good at
powering down devices, in fact, it is quite retarded in that area (mostly
because half the devices out there have hardware bugs and die horrible
deaths that can only be ressurected by a full hardware reset when you power
them down).

> I know the tipical advices on how to mantain a battery, the point is that
> for sure the battery are died cause of a wrong power managing under linux,
> but actually I don't know what to do to solve the problem.

So, you don't do more than one deep drain every 10 or so cycles?

  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh