Ok,  I'll leave the batter out for now.  Thanks!! ------------------------ Keith Smith --- On Tue, 10/11/11, Bryan O'Neal wrote: From: Bryan O'Neal Subject: Re: LaTop battery care and life expectancy To: "Main PLUG discussion list" Date: Tuesday, October 11, 2011, 6:56 PM Don't forget the issues with heat. the longer and higher the heat exposure the shorter the battery life. Also for my primary laptop I will remove the battery entirely if I am plugged in and intend to run for a while. Doing so gives me years longer on one battery. On 10/11/11, keith smith wrote: > > Thank you Joseph for take the time to explain all this to me.  I think I > understand better.  Since my laptop runs without a batter if plugged in I > assume I should only place the batter in my laptop when I plan to run it on > batter power only. > > The battery has been out for several months and it is still at 80% .  Will > it hurt the battery to let it self discharge for a few months? > > Thank again for this wealth of info and thank you to everyone who responded. > > ------------------------ > > Keith Smith > > --- On Sun, 10/9/11, Joseph Sinclair wrote: > > From: Joseph Sinclair > Subject: Re: LaTop battery care and life expectancy > To: "Main PLUG discussion list" > Date: Sunday, October 9, 2011, 2:47 PM > > All Lithium-Ion batteries have similar issues and, in general, similar > recommendations for care. > Keep in mind, however, that different chemistries produce very different > results, lead acid is very different from NiCd, NIMH, or LiIon.  Different > batteries using the same general chemistry may still have very different > specific chemistry to meet particular cost/current/charge/voltage > characteristics. Lithium ion, for example, has at least 8 primary > chemistries (e.g. LiPo, LiFe, LiZnCo, etc...), each with a hundred or more > variations. > Solar systems often use deep-cycle lead-acid because it is cheap, mature, > and very rugged.  That makes comparing solar experience to laptops somewhat > difficult. > > Some newer Lithium Ion batteries use new chemistry (e.g. Si cathodes in > charge-carrier flexible polymer matrix to accommodate swelling during > charge/discharge) to adapt to the issues below, but all still face the same > challenges to a greater or lesser extent. > > 1) Lithium Ion involves actual absorption and release of Lithium atoms by > anode and cathode. > > This means that there is physical stress on the battery elements, and over > time this will damage the materials.  Deep discharge cycles and higher > current drain will make these happen faster. > Your cellphone battery has low current drain and long cycles, compared to a > laptop, and will tend to last longer as a result. > Letting your battery fully discharge before charging it will cause damage, > but LiIon also has an explosive chemistry, so power management circuitry > manages the battery, and turns off a phone when there is still about 20% > charge left in the cell to mitigate this for cellphone batteries. > The ideal usage is to charge at about 30% and not leave the cell above 70% > for too long (see issue 2 for the reason). > > 2) Lithium Ion current limits are dependent on the Li mobility, which > requires highly solvent electrolytes to permit high current usage. > > This means that the anode and cathode materials will dissolve in the > electrolyte over time, and, because of the electrical potential between > anode and cathode, will form whisker structures that eventually short across > the gap between the electrodes. > Leaving the cell fully charged for a long time (or constantly charging it > when not in use) will encourage these whisker structures to grow because it > maintains a higher potential between the electrodes.  This is why leaving a > battery in a charger for a long time (months or years depending on the > battery and charger) will eventually result in a dead battery, even though > it was never really used. > Modern charging circuitry could account for this by discharging the battery > periodically, but laptops and other consumer-oriented devices generally do > not in order to maintain immediate readiness for on-battery use while > charging. > The recommendation is to actually use the device powered by the battery from > most of the time, and only add A/C power to recharge, when planning to > disconnect in the near future, or when usage duration is reasonably expected > to exceed battery life (even then starting on battery and adding A/C when > charge drops below 50% often helps).  It's also best not to leave a laptop > always connected to power, and only plug in when charging is actually > needed. > > > In the end, the reason a cellphone battery often lasts so much longer than a > laptop battery (typically 2-3 times as many charge/discharge cycles) is more > about the different power requirements of the two uses and the specific > structure and chemistry choices made to match battery to load. > Research is constantly advancing battery and other electrical energy storage > technologies, so the performance one may expect for a given usage are > constantly changing, and different manufacturers may use very different > approaches to meet specific cost and performance criteria.  This makes > comparing, or even predicting, battery life very difficult, to the point of > being little more than a guess, so the best advice I know is to simply use > the device in a reasonable manner, and keep an eye on the lifespan indicator > via the battery information probe available in Linux so you have some > advance warning when you'll need to purchase a new battery. > > ==Joseph++ > > On 10/09/2011 01:22 PM, keith smith wrote: >> >> >> I've had several laptops and battery longevity has always been an issue.� >> Not how long it will run my laptop before completely discharging, but how >> long it will be before that battery is no good.� What I do not understand >> is why or how a battery can go bad from being in a laptop that is plugged >> in and why there is a overcharging issue. � >> >> I have two frames of reference, maybe three.� My cordless phone battery >> lasts for years.� I recently started researching solar power.� Seems some >> think the battery's life is extended by not draining it and having a >> constant change trickling into it.� One of the videos said the life of the >> battery was in cycles. >> >> My cellular phone is 3 and a half years old.� My wife tends to forget to >> charge her phone periodically and the battery discharges to the point the >> phone shuts down.� We switch batteries because I keep mine charged for the >> most part and rarely leave home because I work out of my house. >> >> The battery in my last laptop, about 8 years ago, went out in about 3 >> years.� >> >> I have removed the battery from my current laptop hoping to extend it's >> life expectancy.� I rarely using my laptop away from my home office.� When >> I do I try not to go on battery power, however the battery is being >> charged at that point. >> >> My experience makes me wonder why my cellular battery can last 3 plus >> years and might last 5 or 6 years, maybe longer. � And my laptop battery >> is only good for 2 or 3 years. >> >> I've read a lot about laptop battery care, however it is still not clear >> how to keep from wasting a perfectly good battery in just a few years .� >> I'd really like to be able to buy a laptop and be able to use it for 5 >> years.� What is the best way to approach laptop batteries? >> >> Thank you for your help. >> >> ------------------------ >> >> Keith Smith >> >> >> >> --------------------------------------------------- >> PLUG-discuss mailing list - 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