Re: laptop battery cycling
acpi -b (?) reg., steef Doug wrote: On 05/27/2012 09:57 PM, Scott Ferguson wrote: On 28/05/12 11:37, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. Your Li-ion battery will have a longer life if it's stored in a well sealed plastic bag in the 'fridge with a 40% charge than on constant maintenance (trickle) charge plugged into the laptop. Take it out of the 'fridge and fully charge prior to using. Keep it in the 'fridge state when running on mains. /snip/ I've often wondered, after reading this advice time and time again: how do you determine that the battery has a 40% charge? --doug -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4fc31855.9080...@home.nl
Re: laptop battery cycling
On Mon, 2012-05-28 at 07:10 +0200, Ralf Mardorf wrote: On Mon, 2012-05-28 at 00:01 -0400, Doug wrote: On 05/27/2012 09:57 PM, Scott Ferguson wrote: On 28/05/12 11:37, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. Your Li-ion battery will have a longer life if it's stored in a well sealed plastic bag in the 'fridge with a 40% charge than on constant maintenance (trickle) charge plugged into the laptop. Take it out of the 'fridge and fully charge prior to using. Keep it in the 'fridge state when running on mains. /snip/ I've often wondered, after reading this advice time and time again: how do you determine that the battery has a 40% charge? To overdo things can also shorten lifetime. Some plastic pin will break and you can't mount the batteries with 100% more lifetime anymore. Don't forget to heat the battery in an open fire, when it was in the fridge. Store it in a well sealed asbestos bag before doing this :p -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1338182502.2458.11.camel@precise
Re: laptop battery cycling
On 28/05/12 14:01, Doug wrote: On 05/27/2012 09:57 PM, Scott Ferguson wrote: On 28/05/12 11:37, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. Your Li-ion battery will have a longer life if it's stored in a well sealed plastic bag in the 'fridge with a 40% charge than on constant maintenance (trickle) charge plugged into the laptop. Take it out of the 'fridge and fully charge prior to using. Keep it in the 'fridge state when running on mains. /snip/ I've often wondered, after reading this advice time and time again: how do you determine that the battery has a 40% charge? --doug Depends on the laptop. With the Thinkpad/Levenos - a battery charge indicator in the BIOS and/or read the state from tm_smapi (acpi tends to be very inaccurate). Both methods are only reliable when the battery gauge is calibrated using the BIOS tool (the older the model, the more often that is required). I usually use kde-power tools set to shutdown at 40% and just leave it running till then. After shutdown I bag the battery with a little dry rice and put in the 'fridge (gas tight freezer or oven bags, not polyethylene). The rice desiccant is to absorb any moisture that condenses on the cold battery when you remove it from the 'fridge (LiAlH4 likes water). NOTE: I've discovered that even if the battery has been in a warehouse on a shelf unused for 4 years - it has little useful life left. Those genuine Thinkpad/Levono replacement battery bargains from China on eBay aren't always bargains. If the laptop is more than 2 years old, buy a recent repacked or third party battery - not an original. I could be wrong - in which case I've got some original Toshiba PA3356U-3BAS and ASUS U5FL721 batteries at postage prices (make great paperweights and conversation pieces). Kind regards -- Iceweasel/Firefox/Chrome/Chromium/Iceape/IE extensions for finding answers to questions about Debian:- https://addons.mozilla.org/en-US/firefox/collections/Scott_Ferguson/debian/ -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4fc3403e.30...@gmail.com
Re: laptop battery cycling
Robert Holtzman wrote at 2012-05-27 20:37 -0500: how many cycles is a battery like mine good for? If your laptop supports SMAPI, *use it*. In my opinion, it *really* helps increase the lifespan of the battery. It is unfortunate that more devices do not support SMAPI or an equivalent. My battery remains in my laptop all the time (and so remains at least warm most of the time), and my laptop is connected to AC power most of the time (except for when suspended and moving). I have configured SMAPI with a stop_charge_thresh of about 85 and start_charge_thresh of about 40. This means that the battery never fully charges or discharges, and that often when I connect to AC power it remains idle rather than charging. I do change the settings once every year or 2 in order to recalibrate the battery gauges. I purchased the laptop (and battery) in 2007; the battery will soon be 5 years old. The first_use_date is 2007-08. The cycle count is 446 and the design_capacity divided by last_full_capacity is about 80%. signature.asc Description: Digital signature
Re: laptop battery cycling
On Sun, 27 May 2012 18:37:49 -0700, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. This raises two questions. First, is it true that laptop batteries don't have overcharge protection, and second, how many cycles is a battery like mine good for? There's a true I've experienced when it comes to all sort of batteries (lithium, polymer, lead acid based...): they degrade very quickly so forget about what would be the correct cycles and buy a new battery every 4/5 years; may be the Mother Earth won't be happy with that choice but your devices will thank. Still waiting for a true battery to be developed :-) A good source to get more info on this: http://batteryuniversity.com/ Greetings, -- Camaleón -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/jq06ik$rhl$8...@dough.gmane.org
Re: laptop battery cycling
On Sunday, May 27, 2012 21:37:49, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. That's correct most of the time. This raises two questions. First, is it true that laptop batteries don't have overcharge protection, and second, how many cycles is a battery like mine good for? Most laptop batteries today are Lithium-Ion type. Lithium-Ion batteries get damaged when they are at either extreme in terms of charge. At 100% charge the Lithium-Ion mixture can crystalize and the battery looses capacity. At near 0% a Lithium-Ion battery is at risk of exploding, so there is an internal safety circuit to permanently disable the battery if the battery charge is brought too low. The best storage charge level for Lithium-Ion is 40%. The best option for Thinkpads is to install the packages 'tp-smapi-source' and 'tp-smapi-dkms', the latter which willl build the tp-smapi kernel module. [Read the docs that come with tp-smapi-source, which will explain more about Lithium-Ion battery thresholds.] This allows setting the low and high charge thresholds via /etc/sysfs.conf [after the 'sysfsutils' package has been installed] with rules such as: devices/platform/smapi/BAT0/start_charge_thresh = 30 devices/platform/smapi/BAT0/stop_charge_thresh = 91 With rules such as the above, the laptop can be on the charger and the battery plugged in and sitting at 40% and NOT be charging. This means that the laptop can safely be on the charger all the time, and yet not damage the battery. I'd like to think there is a similar utility to do this for non-Thinkpad hardware, but I haven't looked for it much. Final note on battery tech: Nickel-Metal-Hydride (NiMh) and Nickel-Cadmium (NiCad) batteries both exhibit an effect called memory, so they should always be fully discharged followed by a full charge. So be sure to know the type of battery your laptop is using. -- Chris -- Chris Knadle chris.kna...@coredump.us GPG Key: 4096R/0x1E759A726A9FDD74 signature.asc Description: This is a digitally signed message part.
Re: laptop battery cycling
On Mon, 28 May 2012 08:16:53 +0200, steef wrote in message 4fc31855.9080...@home.nl: acpi -b (?) ..I raise you i: arnt@celsius:/tmp$ acpi -bi Battery 0: Unknown, 91% Battery 0: design capacity 5200 mAh, last full capacity 5200 mAh = 100% arnt@celsius:/tmp$ ..acpi -V and acpi -h are also handy. ;o) -- ..med vennlig hilsen = with Kind Regards from Arnt Karlsen ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20120528225506.521af...@celsius.lan
Re: laptop battery cycling
On 28/05/12 11:37, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. Your Li-ion battery will have a longer life if it's stored in a well sealed plastic bag in the 'fridge with a 40% charge than on constant maintenance (trickle) charge plugged into the laptop. Take it out of the 'fridge and fully charge prior to using. Keep it in the 'fridge state when running on mains. This raises two questions. At least :-) First, is it true that laptop batteries don't have overcharge protection, No. At least in your case it's built-in to the battery. and second, how many cycles is a battery like mine good for?' At least 300 depending on storage and use. My T60 has the extended battery which still holds about 2 and a half hours performance time after 300 full discharges over 4-5 years - but it's usually kept in the 'fridge. As a general rule you should have between 70 and 85% of the capacity left after 200 discharges. Most manufacturers rate the lifetime at 3 -5 years and 300 - 500 discharge cycles (less if kept on full charge and at higher temperatures). You might find the following reference useful:- http://www.thinkwiki.org/wiki/Maintenance Kind regards -- Iceweasel/Firefox/Chrome/Chromium/Iceape/IE extensions for finding answers to questions about Debian:- https://addons.mozilla.org/en-US/firefox/collections/Scott_Ferguson/debian/ -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4fc2db88.1090...@gmail.com
Re: laptop battery cycling
On 05/27/2012 09:57 PM, Scott Ferguson wrote: On 28/05/12 11:37, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. Your Li-ion battery will have a longer life if it's stored in a well sealed plastic bag in the 'fridge with a 40% charge than on constant maintenance (trickle) charge plugged into the laptop. Take it out of the 'fridge and fully charge prior to using. Keep it in the 'fridge state when running on mains. /snip/ I've often wondered, after reading this advice time and time again: how do you determine that the battery has a 40% charge? --doug -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4fc2f87f.9010...@optonline.net
Re: laptop battery cycling
On Mon, 2012-05-28 at 00:01 -0400, Doug wrote: On 05/27/2012 09:57 PM, Scott Ferguson wrote: On 28/05/12 11:37, Robert Holtzman wrote: For the record, I'm running a Lenovo T420i with a 6 cell battery. In the past I've been told that it's bad practice to run a laptop on AC with the battery installed because it would cause reduced battery capacity. Your Li-ion battery will have a longer life if it's stored in a well sealed plastic bag in the 'fridge with a 40% charge than on constant maintenance (trickle) charge plugged into the laptop. Take it out of the 'fridge and fully charge prior to using. Keep it in the 'fridge state when running on mains. /snip/ I've often wondered, after reading this advice time and time again: how do you determine that the battery has a 40% charge? To overdo things can also shorten lifetime. Some plastic pin will break and you can't mount the batteries with 100% more lifetime anymore. Don't forget to heat the battery in an open fire, when it was in the fridge. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1338181837.2458.7.camel@precise
