From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jochen Reinwand Subject: Re: Completely discharging LION batteries Date: Thu, 12 Dec 2002 12:22:43 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <200212121222.43960.jbr.1@gmx.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Frank Mehnert , acpi-devel-pyega4qmqnRoyOMFzWx49A@public.gmane.org List-Id: linux-acpi@vger.kernel.org > > > I'm using Linux 2.4.20 together with the acpi patches > > > 20021205-2.4.20 on a > > > Thinkpad T20. If I use two batteries (the builtin and a > > > second in the Ultra- > > > Bay), the second battery first gets discharged _completely_ > > > and after that the internal battery is used. > > > > That's normal, but yes it is not the smartest idea to do. > > What I'm wondering about is that in the Windows 2000 Help of > the Thinkpad Laptop, IBM advises that it is better to discharge > the battery sometimes completely to refresh the full capacity > at least partly. That advise is completely the opposite of what > I've seen. But it could be an mistake in their documentation or > they could target NiMH batteries. Interesting informations about Li-ion batteries can be found at http://www.buchmann.ca/. It seems to be not available at the moment. But here are a few tips from the page: - Charge the Li-ion often, except before a long storage. Avoid repeated deep discharges. - Keep the Li-ion battery cool. Prevent storage in a hot car. Never freeze a battery. - If your laptop is capable of running without a battery and fixed power is used most of the time, remove the battery and store it in a cool place. - Avoid purchasing spare Li-ion batteries for later use. Observe manufacturing date when purchasing. Do not buy old stock, even if sold at clearance prices. But there is also a note on the site that a deep discharge cannot bring back I higher full charge level. On this list I once found the tip that it should work. I tried it and my battery was again able to charge to full capacity. btw: DO NEVER COMPLETELY DISCHARGE A LI-ION! Normal electronic devices can not discharge a Li-ion completely. So it should be ok to discharge until the device powers of. There is still enough power in the battery to lit a lamp for a long time. But that would discharge it definitively to low! Jochen ------------------------------------------------------- This sf.net email is sponsored by: With Great Power, Comes Great Responsibility Learn to use your power at OSDN's High Performance Computing Channel http://hpc.devchannel.org/