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| Thread ID: 56273 | 2005-04-01 01:51:00 | laptop batteries holding charge | Morgenmuffel (187) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 340115 | 2005-04-01 01:51:00 | toshiba M30 laptop purchased january 2005 Do laptop batteries normally lose their charge completely (from being fully charged) if left sitting, not being used also in the space of one week it went fom being fully charged to 25% charged without being used Thanks in advance |
Morgenmuffel (187) | ||
| 340116 | 2005-04-01 02:18:00 | Yes Lithium-ion batterries have quite a high self-discharge rate, and nicads are not far behind. In addition, the older lithium-ion batteries get, the faster they lose their charge. In my experience (and usage patterns) they are no better than nicads in many respects. Google will tell you more. Cheers Billy 8-{) |
Billy T (70) | ||
| 340117 | 2005-04-01 05:06:00 | A lithium-ion should hold its charge quite well . It's an "advanced technology" . I have one I bought from DSE for $5 because they hadn't sold it for too, too, long, so it had been a couple of years without being charged . It's at over 90% . I'd say you should get a replacement of one you've had for three months . If I had 3 month old NiXXs which lost 75% of charge in a week of no use I'd be back for replacements too . |
Graham L (2) | ||
| 340118 | 2005-04-01 06:01:00 | toshiba M30 laptop purchased january 2005 Do laptop batteries normally lose their charge completely (from being fully charged) if left sitting, not being used also in the space of one week it went fom being fully charged to 25% charged without being used Thanks in advance Just make sure that you are "shutting down" fully, and not just going to "standby" though, or internal computer draw will run the battery down. |
godfather (25) | ||
| 340119 | 2005-04-01 06:05:00 | They are ok when new and out of the computer Graham, but if left in the computer they run down quite quickly. Their in-built protection circuit also adds to the discharge rate. Keeping them cool helps as the discharge rate rises sharply with temperature. Taking all factors into consideration they can go down at 10%/24hrs, which fits with 25% after 1 week so Nigel's experience is not extraordinary, however he could have a bad battery, and the power meter might not be all that accurate either. Cheers Billy 8-{) |
Billy T (70) | ||
| 340120 | 2005-04-01 06:17:00 | The protection circuits (marvelous chips ... I've had a look at the data sheets, and have a few applications in mind) use microamps (or less). And they are in the battery all the time. 10% in 24 hours would be a continuous drain of over 12 mA (for a 3AH battery). GF's suggestion that the computer might be running seems more plausible, but what is it doing? That sort of drain is too low.;) |
Graham L (2) | ||
| 340121 | 2005-04-01 06:31:00 | The protection circuits (marvelous chips ... I've had a look at the data sheets, and have a few applications in mind) use microamps (or less). And they are in the battery all the time. 10% in 24 hours would be a continuous drain of over 12 mA (for a 3AH battery). Yes, I know it doesn't sound likely, but some lithium battery pack makers quote 5%/24hrs natural discharge plus 3%/24hrs for the protection circuit. Part of that protection is cell voltage balancing and that implies parallel resistance. Add any fixed drain that the laptop may take even when switched off, plus very warm temperatures after use and it is not hard to see where the capacity can go. Keeping the battery in a plastic bag in the fridge between uses will make a big difference. My Toshiba Portege has a similar discharge rate and that is with a brand-new OEM high capacity battery. Cheers Billy 8-{) |
Billy T (70) | ||
| 340122 | 2005-04-01 06:42:00 | So the manufacturers can't sell them, Billy? After manufacture, they are unlikely to be sold in less than a month or so. If Li-Ion cells drop below a critical point, they are unrecoverable. The protection circuits won't allow them to be charged. | Graham L (2) | ||
| 340123 | 2005-04-01 20:47:00 | If Li-Ion cells drop below a critical point, they are unrecoverable. The protection circuits won't allow them to be charged. So we need to keep batteries in laptops and charge them (use the laptop) regularly, say weekly? I recall a similar thread on this topic last year, which said that laptop batteries should be taken out (assuming the laptop is normally used with a power cord) to ensure a long battery life. What is correct? |
Strommer (42) | ||
| 340124 | 2005-04-01 21:59:00 | So the manufacturers can't sell them, Billy? After manufacture, they are unlikely to be sold in less than a month or so . If Li-Ion cells drop below a critical point, they are unrecoverable . The protection circuits won't allow them to be charged . I don't know the answer to that one Graham, but I do know how fast my new batteries self-discharge . Dont forget though that the self discharge will taper off as the voltage reduces and what is too low to run a computer is not necessarily all that close to the critical "non-recovery" point . That critical point is not actually non-recoverable either and there is technology out there that can recover from shutdown . Take a look at This Link ( . batteryuniversity . com/parttwo-34 . htm" target="_blank">www . batteryuniversity . com) Cheers Billy 8-{) |
Billy T (70) | ||
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