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Does anybody know if it is necessary/advisable to discharge them before re-charging them ?
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Usually it is said that any rechargeable battery will last longer if you recharge it while it is almost discharged (I plug in my phone to charger only when it starts to complaint about low battery).
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Movilogo,
Your phone will have Lithium Ion batteries and you should try to avoid running the battery down completely.
Lion batteries prefers a partial rather than a full discharge and full discharges should be avoided when possible.
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>> It isn't.
Lenovo says it is.
1. Your new IBM Lenovo laptop battery comes in a discharged condition and must be charged before use (refer to your computer manual for charging instructions). Upon initial use (or after a prolonged storage period) the battery may require two to three charge/discharge cycles before achieving maximum capacity.
2. When charging IBM Lenovo laptop battery for the first time your computer may indicate that charging is complete after just 10 or 15 minutes. This is a normal phenomenon with rechargeable batteries. Simply remove the battery from the computer and repeat the charging procedure.
3. It is important to condition (fully discharge and then fully charge) IBM Lenovo laptop battery every two to three weeks. Failure to do so may significantly shorten the battery's life (this does not apply to Li-ion batteries, which do not require conditioning). To discharge, simply run your device under the battery's power until it shuts down or until you get a low battery warning. Then recharge the battery as instructed in your user's manual.
4. If IBM Lenovo laptop battery will not be in use for a month or longer, it is recommended that it be removed from the device and stored in a cool, dry, clean place.
5. It is normal for IBM Lenovo laptop battery to become warm during charging and discharging.
6. A charged IBM Lenovo laptop battery will eventually lose its charge if unused. It may therefore be necessary to recharge the battery after a storage period.
How can I maximize battery performance?
There are several steps you can take to insure that you get maximum performance from your IBM Lenovo laptop battery:
1. Breaking In New Batteries - new batteries come in a discharged condition and must be fully charged before use. It is recommended that you fully charge and discharge your new battery two to four times to allow it to reach its maximum rated capacity.
2. Preventing the Memory Effect - Keep your battery healthy by fully charging and then fully discharging it at least once every two to three weeks. Exceptions to the rule are Li-ion batteries which do not suffer from the memory effect.
3. Keep Your Batteries Clean - It's a good idea to clean dirty battery contacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and your portable device.
4. Exercise Your Battery - Do not leave your battery dormant for long periods of time. We recommend using the battery at least once every two to three weeks. If a battery has not been used for a long period of time, perform the new battery break in procedure described above.
5. Battery Storage - If you don't plan on using the battery for a month or more, we recommend storing it in a clean, dry, cool place away from heat and metal objects. Ni-Cd, Ni-MH and Li-Ion batteries will self-discharge during storage; remember to break them in before use.
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That's a Li-ion battery, not a NiMH.
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R/C flying forums are pretty handy for battery advice for NIMH, LiIon, LiPo (BobbyG would like these, see the video on www.liposack.com/ ) & LiFe types.
LiPos are where it's at currently, that's what i fly. Not exploded one yet but had a close call once.
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Lithium Polymer allows batteries to take irregular shapes to aid packaging. I think the non-user replaceable batteries in some Apple kit must be Lithium Polymer for this reason.
Edit: And another Apple reason - to make it expensive for the end user to swap batteries.
Last edited by: rtj70 on Tue 7 Sep 10 at 17:44
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>> That's a Li-ion battery, not a NiMH.
I am sure you know more than Lenovo.
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Look on their website, you gonk, or read global-laptop-batteries.com properly. You'll be arguing with just yourself from now on.
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yes yes I am agreeing - you know best. Always.
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site.greenbatteries.com/documents/Battery_Guide.pdf
Dont no how to make it clickable cos iamabilder.
M
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>> Does anybody know if it is necessary/advisable to discharge them before re-charging them ?
b*****
Last edited by: corax on Tue 7 Sep 10 at 20:28
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Why does this swear filter delete my whole stuffing post when it decides a word is not appropriate? Why can't it just put some asterisks in place of that (mild) word, and leave the rest? It now means that borasport will not get the benefit of my infinitely superior knowledge regarding batteries as I won't be retyping it all again :-)
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A NiMh battery should never be completely discharged. The advice offered by Lenovo is a consequence of the slightly more advanced charging circuitry installed in laptop battery packs. While it will allow you to maximise the battery capacity, the risk of damaging the battery is minimal because the battery "brain" will disconnect it when cell voltages fall below a certain level.
The ONLY batteries that should be subjected to regular deep discharge cycles are NiCad, and I don't even know if you can buy them any more.
Having said that, I don't see any physical reason why a single NiMh cell shouldn't be completely discharged (ie, if you're using AA size batteries in a torch or something), but NiMh battery packs should never be allowed to empty completely, as you'll actually encounter a situation where other cells in the pack will begin to recharge the emptier ones...
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Look at the references and you will see the "advice" is for Li ion.
You can buy Nicads at many, many places. I do not see why these should be regularly discharged (unless you're referring to the almost mythical "memory effect").
Corax was going to give chapter & verse, but got chopped bt the swear-f*****.
Last edited by: FotheringtonTomas on Wed 8 Sep 10 at 15:43
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The Memory effect is far from Myth.
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Here's a start for you - there's a lot more on this out there:
en.wikipedia.org/wiki/Memory_effect
And more..
www.dansdata.com/gz011.htm
and more and more. I leave investigating this as an exercise for your good self.
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In my experience, the lifetime of laptop batteries is shorter than for anything else. I've had batteries last for ten years in a mobile phone and a cordless drill, and all four of our wireless phones are going strong after 8 years. Laptops, about 3 years max, so I'm not sure I'd take much notice of Mr Lenovo...
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>> In my experience, the lifetime of laptop batteries is shorter than for anything else. I've
>> had batteries last for ten years in a mobile phone and a cordless drill, and
>> all four of our wireless phones are going strong after 8 years. Laptops, about 3
>> years max, so I'm not sure I'd take much notice of Mr Lenovo...
I agree totally, JBJ, with one exception. My work laptop is coming up 5 years old in December. It's a pretty bum basic Dell D410 which runs off mains power probably 90% of the time. Yet I can still get a good three hours out of the battery if I get caught short.
Every other laptop I've had has developed a virtually useless battery after between a year and 18 months of similar use.
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All IMHO. Your mileage and experience may vary :)
By definition if you've had batteries last 8 to 10 years they are using the type that was in vogue that long ago.
Most likely NiCd, which is robust and extremely durable if used sensibly.
Almost anything reasonably new and exotic is likely to use Lithium technology, giving more power for a given volume and weight than NiCd and NiMh. With obvious advantages for mobile and laptop/netbook applications.
But, LiIon is scrap in 3 years in heavy use.
A mobile may run a bit longer if it runs several days between charges when new, but the time between charges diminishes as the number of charge/discharge increases.
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The Dell battery is a LiIon, but it has only been deep cycled maybe three or four times in 5 years. It tends to be the odd 30-40 mins and then it's plugged into the mains again.
Just last night I spent about a good 90 mins online on battery power, using Wi-Fi, and it was still showing 34% remaining on the Windows power monitor.
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...Laptops, about 3 years max...
Agreed, whatever they are made of, or however they are used.
My Samsung netbook has proved to be a good tool, but the battery capacity is declining after just a few months.
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I don't know what Dell use but they are far superior to any other laptop manufacturer in my experience. I have a new i5 will run for four hours off battery my 3 mpnth old i3 Sony Vaio 80mins. tops. My wife got a new Acer Core2 Duo last summer battery dead after 9 months. 6 month guarantee on Acer batteries.
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I have NiMH AA batteries in the cordless phone. They were not holding a charge very well, so I let them go completely flat while on holiday.
They now hold a charge much better eg: previouslt the low battery beep would wake me in the night if I forgot to put the handset on charge, but now I can leave it off all day with no issue. Can never find the thing now though ;(
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You have to go through discharge and recharge cycle for ALL rechargeable batteries except Li-ions.
As the OP was talking about NiMh then yes, discharge them (not fully flat - till the appliance wont work)
They will all be shot in about 300-1000 charge cycles OR three years on trickle charge.
Last edited by: Zero on Wed 8 Sep 10 at 20:15
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Laptop batteries tend to get killed by either of the following :-
1. the charging circuit charges the battery too fast
2. Heat from the laptop cpu eventually kills the battery
Its mostly number 2 because style and packaging is more important than battery life.
Also the laptop manufacturers want your money and having a duff battery after 18 months is money in their pocket.
Regarding batteries, I tend to let them cycle (run till dead then full charge straight away) about once every 6 months.
I could be wrong but this seems to help the battery last longer.
The only type of battery this should not be performed on the lead acid batteries (sealed and un-sealed).
These types of battery perform better if trickle charged 90% of the time then used 10% of the time.
Regarding Ni-Cad batteries, they have an inherent problem of self discharging that only gets worse over its life.
This is due to dendritic growth of a crystalline structure between the positive and negative terminals.
Not sure if this applies to Ni-Mh battery's though.
Last edited by: diddy1234 on Wed 8 Sep 10 at 21:36
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I have an Acer Aspire in bits with a duff video card at the moment (what a huge beast 21 inch screen)
Its li-ion power pack is shot, not having made its third birthday. The power pack is miles away from the hot parts (nice thermal design in this machine btw) and being so big has hardly ever been off the mains lead.
This and my other laptop experience convinces me that even Li-ion batteries need to be cycled for longer life, and/or three years is your absolute maximum from them.
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All my recent work laptops are plugged in the mains a lot. Eventually the lithium ion batteries fail to hold much charge. You need to discharge and recharge a bit. But it's not my laptop and leaving it plugged in is better for me.
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Remove the battery if the laptop is to be left plugged in, although I think few people, including me, can be bothered.
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Unlike other batteries Lithium Ion start deteriorating the day they are made. This applies however you use or don't use them. They lose up to 20% of their capacity to hold a charge every year so a 5 year old battery will be useless even if it has never been used. Deep discharging will shorten their life further.
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IN use, its not possible to "deep discharge" a laptop battery. They get to a level where the laptop wont work, which is a long way above a discharged battery let alone "deep"
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I though that a laptop would continue to draw power from the battery if switched on even though the battery had insufficient power to operate the machine fully. Presumably that is not correct then?
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>> I though that a laptop would continue to draw power from the battery if switched
>> on even though the battery had insufficient power to operate the machine fully. Presumably that
>> is not correct then?
Not if its powered itself down due to low power. (and most do, they dont sleep they hibernate data out to hard drive) It switches off, and draws no current form the main battery.
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...I though that a laptop would continue to draw power from the battery if switched on...
I read in the instructions to one of my laptops the laptop would stop short of discharging the main battery fully in order not to damage it.
All the settings are held using an 'internal' battery.
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Laptops really dont exploit much of the discharge range of batteries. They have to err heavily on the side of caution as low power = lost data.
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Taking advantage of the thread drift, anybody recommend a source for a battery for a Toshiba laptop -mine's little more then ballast at the moment, sometimes won't provide power long enough to let you log in.
And yes, the laptops about 30 months old and spends most of its time on mains power
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My Tosh is about 4 YO.. Li-Ion battery Ok down to about 30% then drops to 2% in 2-3 minutes.
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Due to the joys of night working, I had forgotten something which may be of interest:
I bought two new identical Tosh laptops, one each for my daughters, 33 months ago.
The way the laptops have been used is the two extremes - one is almost always on mains power, the other is run on battery until it complains and then plugged in.
(Amazingly one daughter listens to what I say, and remembered being told to fully cycle rechargeable batteries years ago, in the NiCd days.)
The laptops now both have very short battery lives - I'll have to ask and find out just how long they run.
Will post again in a day or two with some figures.
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>> The laptops now both have very short battery lives
Probably made little difference then ?
Last edited by: rtj70 on Fri 10 Sep 10 at 01:15
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>> Probably made little difference then ?
We'll see what the figures are when they get back to me, but probably not.
I suspect one of the problems is the amount of power a laptop needs - probably 2 - 3 charge cycles in a full working day as the specification/capacity at the time they were made... so could be around 2000 by now.
But the expected life is 300 to 500 cycles with reasonable precentage of original capacity remaining....
Doomed to failure.
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The answers are coming in instalments, I'm afraid.
The fully cycled battery managed 10 minutes "surfing" before needing a charge, the first time.
By the third time it had stabilised at 16 minutes.
Neither use nor ornament, apart from saving results in the event of a power failure.
I can understand why it is no longer used on battery only.
Regarding the other one (almost always used on mains power)... have reminded it's owner, again, today of the request for battery life information.
She expects it will manage an hour, but I'm not convinced.
Going to see her tomorrow, so can nag in person :)
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And people say that battery cars will soon be the norm.
I'll be long dead before that happens.
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It is said that 2 stroke is the way forward.
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A two-stroke battery! Wow!
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If I see one of them, I may be convinced.
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It's gone full circle in 20 years then. Ford went some way down the two stroke route with a company called Orbital who built a two stroke engine for the Fiesta way back in the early 90's. This was being billed as "the future" back then.
They even had some prototypes on their press fleet at the time, which received generally positive reviews. A 1.2 litre 3 pot stroker with, ISTRC, better performance than the 1.4 four stroke, and better fuel economy than the 1.1.
Would at least solve the issue of the cramped engine bay of a modern car, if nothing else.
i589.photobucket.com/albums/ss336/MotorcyclesFish/IMG_0318.jpg
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Eco Motors are working on something similar -->
www.ecomotors.com/technology
* they're still officially a pie in the sky company, while it's been prototyped and fired up, they're not ready for production yet
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The other battery (always on mains power) managed 46 minutes browsing before the "4 minute warning" appeared.
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I always though two-strokes were a no-no because of emissions.
Mind, that was when you blobbed half a cupful of oil in with the petrol.
It's bound to smoke a bit, isn't it?
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they are knackered - official
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John, it may be a red herring but of all the laptops I, and the wife, have had, the batteries on the Tosh's went very quickly, within 12 months. As did the replacements. Compaq, Dell & Lenovo all lasted much better before the life shrank to "mains only". I guess the batteries all come out of the same factories so maybe Tosh fit a poorer spec. Mind, I am talking several years ago, might be different now.
John
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Yes, the are officially knackered.
They were never all that good - a coupe of hours or so, I suppose.
Cheap and cheerfull, and probably overheated too.
By and large, you get what you pay for: these were 350UKP each, as memory serves...
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NiMH Rechargeables - FotheringtonTomas
