Date: Wed, 17 Mar 2010 17:18:34 +0100 From: Joerg Wunsch <j@uriah.heep.sax.de> To: freebsd-acpi@freebsd.org Subject: Re: Funny battery values (nx6325) Message-ID: <20100317161834.GH52442@uriah.heep.sax.de> In-Reply-To: <1268829363.6171.13.camel@RabbitsDen> <20100317224207.A85436@sola.nimnet.asn.au> <20100317154327.04F841CC18@ptavv.es.net>
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As Kevin Oberman wrote: > FWIW, IBM/Lenovo recommend that, should the battery capacity stuff > get messed up, you FULLY discharge the battery and then re-charge. I'm doing that right now with my TP 600E battery, too. It was completely dead (one out of the three cell pairs had 0.0 V), so I replaced all cells by some other 18650 cells I've got around. While the machine yelled "Battery critically low" after only about 5 minutes of run-time, it already lasts for half an hour now. I hope I'll also be able to re-train the Coulomb meter chip in the battery there. > This is claimed to re-initialize the values stored in the battery > and I found this worked on a battery in my old 600E. Mine did not > have a weird "Design Capacity" value, though. Same here, the "Design capacity" of that TP 600E battery makes sense, unlike on the nx6325. As Ian Smith wrote: > > > Is this consistent or does it vary from boot to boot or if you > > > disconnect and reconnect the battery? > Or try another battery? Only got that one. The machine is normally a semi-desktop one. > > That's right, but it wouldn't be supposed to affect the "Design > > capacity", would it? ;) > It wouldn't be supposed to :) > Tracing back through acpi_cmbat_get_total_battinfo in acpi_cmbat.c > indicates that calculaing remaining time does uses last full > capacity, but from there back through acpi_cmbat_get_bst and > acpi_cmbat_get_bif it's all just retrieval, from acpi packages of > _BST and _BIF Thanks for the analysis! > Most of it must be stored in the in-battery chip, but I don't know > where specs may be, or even whether they all use same protocols. I think this is all called the "Smart Battery specification", which is essentially a layer on top of a standard I²C bus. I once looked at it lightly in connection with a battery control IC as I did build my own battery (out of used 18650 cells, again) for a ham radio transceiver. But I haven't really looked into the Smart Battery specs so far, as my transceiver didn't want to talk it anyway. ;-) > Peter's factor of 10 sounds plausible. Except for the design capacity value. > You can dump your ASL (see Handbook for instructions) and search for > something like: Thanks for that hint, I'll do it as soon as the machine is back here. -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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