Re: [Hampshire] power problem
On Tue, 06 Dec 2011 at 01:01:29PM -, Vic wrote: > > > Li batteries have good charge densities but don't last that > > long unless they are charged and discharged evenly (apparently). > > It's even more complicated than that... > > Li batteries suffer permanent degradation with time. The rate of > degradation is increased with heat and with charge. > > So it would be reasonable to assume that it is best to keep a Li battery > discharged, and then charge it just before it needs to be used. And that > would be wrong; Li batteries that go into deep discharge die immediately. > > I've given up on trying to keep them running. I just buy el cheapo units > from China and expect them to last somewhere around a year. The strange thing is I have old Li-Ion Dell cells that are over a decade old but function perfectly today. The modern Li-poly ones, especially the cheap ones don't last at all. As you say running them hot isn't good for them, my old Dell was always pretty cold. Running them on full charge isn't good for them or fully discahrging them which can be fatal. My mistake was running it full almost all the time and letting it run warm. It wasn't discharged enough and it got hot too often... -- Adam Trickett Overton, HANTS, UK When a Microsoft product is the lesser of two evils, you know for sure that there's something fishy going on. -- anon -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
> >This is not a safe thing to do; a deeply-discharged lithium cell is no > >longer viable. Although you *might* manage to get some charge into it, you > >also might have an incipient internal short. Given the energy density of a > >lithium battery, that can lead to a fire... > > > >Vic. > > > Screwdriver through a Li cell... This is how I blew mine! Well it > was exciting to say the least :) I should say so, they go bang impressivly! -- Adam Trickett Overton, HANTS, UK Any technology distinguishable from magic is insufficiently advanced -- anon -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
On 12/06/2011 02:22 PM, Vic wrote: However, I believe that this minimum charge threshold is actually built into the battery control electronics rather than the battery itself. Yes, it is. That is to say, If I could have bypassed the controller and charged it back up manually, I believe that I would have got some further use out of the battery. This is not a safe thing to do; a deeply-discharged lithium cell is no longer viable. Although you *might* manage to get some charge into it, you also might have an incipient internal short. Given the energy density of a lithium battery, that can lead to a fire... Vic. Screwdriver through a Li cell... This is how I blew mine! Well it was exciting to say the least :) -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk -- -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
> However, I believe that this > minimum charge threshold is actually built into the battery control > electronics rather than the battery itself. Yes, it is. > That is to say, If I could have bypassed the controller and charged it > back up manually, I believe that I would have got some further use out > of the battery. This is not a safe thing to do; a deeply-discharged lithium cell is no longer viable. Although you *might* manage to get some charge into it, you also might have an incipient internal short. Given the energy density of a lithium battery, that can lead to a fire... Vic. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
I can second that. I had my mac book battery - that was dying anyway - completely die on me after leaving it in the car for a week over the Christmas period last year. The combination of the cold weather and the lack of charge caused the battery to go below a threshold, and hence, the battery would never charge again. However, I believe that this minimum charge threshold is actually built into the battery control electronics rather than the battery itself. That is to say, If I could have bypassed the controller and charged it back up manually, I believe that I would have got some further use out of the battery... But after having a Li battery blow on me before, I was reluctant to try it. On 12/06/2011 01:01 PM, Vic wrote: Li batteries have good charge densities but don't last that long unless they are charged and discharged evenly (apparently). It's even more complicated than that... Li batteries suffer permanent degradation with time. The rate of degradation is increased with heat and with charge. So it would be reasonable to assume that it is best to keep a Li battery discharged, and then charge it just before it needs to be used. And that would be wrong; Li batteries that go into deep discharge die immediately. I've given up on trying to keep them running. I just buy el cheapo units from China and expect them to last somewhere around a year. Vic. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk -- -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
> Li batteries have good charge densities but don't last that > long unless they are charged and discharged evenly (apparently). It's even more complicated than that... Li batteries suffer permanent degradation with time. The rate of degradation is increased with heat and with charge. So it would be reasonable to assume that it is best to keep a Li battery discharged, and then charge it just before it needs to be used. And that would be wrong; Li batteries that go into deep discharge die immediately. I've given up on trying to keep them running. I just buy el cheapo units from China and expect them to last somewhere around a year. Vic. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
On Tuesday 06 December 2011 10:06:09 Owain Clarke wrote: > It's not a fortune, but it's too much to spend only to > find out it's something else That is what happened to me. Now I don't know whether I was sent a dud replacement or it is somerthing else that is wrong. :-( Lisi -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
On Tue, 06 Dec 2011 at 09:49:42AM -, Jan Henkins wrote: > Hello Owain, > > Yep, that sounds like a borked battery. I find that lappy batteries can > start giving problems almost from the get-go, but a life-span from around > 18-24 months seems to be the norm. It's inconvenient to say the least, but > luckily Eee batteries are readily available. A quick look on Amazon seems > like depending on your model, a battery should cost between £26-£34 (or > around that). I'm sure that you can most probably find cheaper "unbranded" > batteries elsewhere, bit then again I fully believe that you get what you > pay for in this case... :-) I'd agree, my Novatech V13's battery lasted about 18 months then died. Li batteries have good charge densities but don't last that long unless they are charged and discharged evenly (apparently). Yesterday Novatech sent the replacement I ordered and it's now working perfectly on battery again. I must be more careful to discharge to 50% and recharge it more often, and not store it at maximum charge. Apparently Li batteries like to be discharged more often but less deeply than older technologies. > On Tue, December 6, 2011 08:02, Owain Clarke wrote: > > I wonder if anyone would mind commenting on a problem? I noticed > > that recently my Asus Eee has only been getting up to about 65% of > > charge, and I assumed this is a battery problem (I think it's about > > 18 months old). But then I have noticed a couple of times, that > > even with a reasonable amount of charge, if I unplug the mains > > charger, the computer immediately switches off, so I wondered > > whether there is a more general power problem, or whether that could > > just be indicative of a naff battery. It also sometimes switches > > off when it's suspended, even though the battery appears to have > > quite a bit of charge left. > > -- > Regards, > Jan Henkins > > > -- > Please post to: Hampshire@mailman.lug.org.uk > Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire > LUG URL: http://www.hantslug.org.uk > -- -- Adam Trickett Overton, HANTS, UK Good advice is always certain to be ignored, but that's no reason not to give it. -- Agatha Christie -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
Thanks, Jan. It's not a fortune, but it's too much to spend only to find out it's something else Owain On 06/12/11 09:49, Jan Henkins wrote: Hello Owain, Yep, that sounds like a borked battery. I find that lappy batteries can start giving problems almost from the get-go, but a life-span from around 18-24 months seems to be the norm. It's inconvenient to say the least, but luckily Eee batteries are readily available. A quick look on Amazon seems like depending on your model, a battery should cost between £26-£34 (or around that). I'm sure that you can most probably find cheaper "unbranded" batteries elsewhere, bit then again I fully believe that you get what you pay for in this case... :-) On Tue, December 6, 2011 08:02, Owain Clarke wrote: I wonder if anyone would mind commenting on a problem? I noticed that recently my Asus Eee has only been getting up to about 65% of charge, and I assumed this is a battery problem (I think it's about 18 months old). But then I have noticed a couple of times, that even with a reasonable amount of charge, if I unplug the mains charger, the computer immediately switches off, so I wondered whether there is a more general power problem, or whether that could just be indicative of a naff battery. It also sometimes switches off when it's suspended, even though the battery appears to have quite a bit of charge left. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] power problem
Hello Owain, Yep, that sounds like a borked battery. I find that lappy batteries can start giving problems almost from the get-go, but a life-span from around 18-24 months seems to be the norm. It's inconvenient to say the least, but luckily Eee batteries are readily available. A quick look on Amazon seems like depending on your model, a battery should cost between £26-£34 (or around that). I'm sure that you can most probably find cheaper "unbranded" batteries elsewhere, bit then again I fully believe that you get what you pay for in this case... :-) On Tue, December 6, 2011 08:02, Owain Clarke wrote: > I wonder if anyone would mind commenting on a problem? I noticed > that recently my Asus Eee has only been getting up to about 65% of > charge, and I assumed this is a battery problem (I think it's about > 18 months old). But then I have noticed a couple of times, that > even with a reasonable amount of charge, if I unplug the mains > charger, the computer immediately switches off, so I wondered > whether there is a more general power problem, or whether that could > just be indicative of a naff battery. It also sometimes switches > off when it's suspended, even though the battery appears to have > quite a bit of charge left. -- Regards, Jan Henkins -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
[Hampshire] power problem
I wonder if anyone would mind commenting on a problem? I noticed that recently my Asus Eee has only been getting up to about 65% of charge, and I assumed this is a battery problem (I think it's about 18 months old). But then I have noticed a couple of times, that even with a reasonable amount of charge, if I unplug the mains charger, the computer immediately switches off, so I wondered whether there is a more general power problem, or whether that could just be indicative of a naff battery. It also sometimes switches off when it's suspended, even though the battery appears to have quite a bit of charge left. Any opinions? Thanks all Owain -- Sent from my winning combination of George Parker and Basildon Bond -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --