[ltp] WARNING: Lenovo ThinkPads and 65W power supplies

[Joerg Bruehe]

Henrique,


thanks for the warning and the thorough explanation - I appreciate that.

Henrique de Moraes Holschuh wrote:
> This is a warning to owners of any Lenovo ThinkPads that own 65W AC pow=
er
> adaptors.
>=20
> Apparently, the 65W power supplies alone are NOT sufficient to power th=
e
> notebook in all scenarios.  The battery can be used to supply power
> during demand peaks that the external power supply cannot meet, and the=

> firmware knows this.

I own a Thinkpad R51 which I bought in March, 2005. The power supply is
not labeled any wattage, so I'd like to know whether the 65 W (or 90 W)
you mention is some nominal rating, or can be taken as the product of
voltage and current?

Mine is labeled 16 V, 4.5 A, so the result is 72 W. Is that a third
model (I realize there may be plenty), or one you classify as 65 W?

(I should run it via a Watt-meter, just for curiosity, but without
knowing the efficiency this won't tell me much either.)

>=20
> [[...]]
>=20
> You are advised to:
>=20
>   [[...]]
>=20
>   2.  Never use the 65W power adapter *WITHOUT* a battery, just in case=

>       the operating system is not doing its job properly;

Combined with your earlier warnings against fully charging (or emptying)
the battery, this just raises the importance of setting proper limits -
the technique of running the Thinkpad without the battery (assuming a
reliable mains supply) would violate this current recommendation.

>=20
>   [[...]]

Thanks for all your writings!

J=F6rg

--=20
Joerg Bruehe  - persoenliche Aeusserung / speaking only for himself
mailto:joerg.bruehe@web.de