Laptop battery, have i been screwed ? - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: April 22, 2011, 06:47:53 am
content: Well I bought me a new battery for my HP NC4200 laptop that I got off ebay. It's a decent machine, ok it's like 5 year old but at the time it was a £1300 laptop for business people and that was with the sum total of 512 MB of RAM (256 if you were unlucky). Mine had been upgraded by the seller to it's maximum 2 GB woo hoo. It has a proper graphics controller no onboard shit and like every morning I'm typing on it despite the fact that my work desktop is sitting just behind it struggling to even stay up and running although being the same age.So I decided to reward my trusty laptop with a new battery so that I have some added mobility and freedom. But something odd is happening: it won't charge to 100%. Now as far as I'm aware the battery has the controller and the battery tells the laptop when it is charged. It started at 90% I thought ok maybe it needs "running in" so I proceeded to fully charge and fully discharge it. second timearound i got to 89% when it stopped and this time I've hd it on charge all night, it still shows a charging light but it has topped 88%. Do you see the same pattern forming as me ? yea looks like I started 10% down and am loosing 1% every time i recharge.Does anyone have any reassurance for me ? is this normal ?

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 22, 2011, 07:27:48 am
content: any battery, no matter how expensive it is, will decay in performance, in my experience at least. if you bought the original battery, then maybe its an old stock. if its china clone, then you should already know the answer

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: April 22, 2011, 07:28:22 am
content: I find that the more intelligent charging schemes avoid holding the battery at 100% indefinitely. For example, if I leave my Macbook pro plugged in all day under use, it'll hover around 90-95% for the sake of avoiding undue battery stress. But then your numbers seem a little low for that to be the case, and it sounds like your charge cycle is ENDING in the high 80s/low 90s, vs going full and settling down. So yes, that sounds a little wonky.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 22, 2011, 08:22:54 am
content: Battery capacity measurement is far from an exact science - a few % difference in readings is meaningless. Actual run time is the only true measure.In some cases it can take a battery manager a few charge/discharge cycles to learn the battery characteristic before it gives meaningful figures.

author: Fraser
author_rank: Super Contributor
timestamp: April 22, 2011, 09:18:08 am
content: Also, do some googling on battery calibration. Many older laptops used to suffer from battery level calibration issues and manufacturers produced a calibration routine to reset them. This was usually an issue with the laptop 'thinking' the battery was discharged before it actually was. The calibration usually effected the lower end of the battery metering rather than the top end.A laptop I had several years ago required the user to fully charge the battery for X hours and then FULLY discharge it until the laptop shut itself down. A full recharge then reset the calibration of the batteries internal charge level management.As has been stated, a NOS Lithium Ion battery can be a risky purchase as officially Lithium Ion batteries become OLD and spec not guaranteed at 5 years of age. Brand new Lithium Ion batteries , and others, require several charge/discharge cycles before they will produce their full capacity.... it's a chemistry thing !A good test of a batteries performance is to download a battery test program (there are many free ones available) and see how long the battery lasts from full charge to auto shut-down. The programs simulate normal usage with Word etc so give an idea of total continuous run time.I once tested my six Dell X300 batteries and the best one was NOS. It exceeded the manufacturers spec for run time and it was at least 8 years old but unused. The used batteries varied from around 90% capacity to less than 50% remaining. It was an interesting little test and the PC did all the testing work itself via the test program.In my experience, you cannot increase the capacity of a tired Lithium Ion battery by charge/discharge cycling as the battery chemistry is basically worn out. A new or unused battery is a different case as I have already mentioned as you are effectively activating the chemistry within the cells that has been dormant for a long period and requires some activity to 'wake it up'.Oh and before I forget...Compatable batteries are a bit like Russian Roulette... I have had some excellent compatable batteries for camcorders etc but have had bad experiences with some 'Uniross' digital camera batteries from China that I believe were probably fake. They had less than 50% of the capability of the OEM battery yet claimed greater Ah capacity ! Many compatable batteries are fine but some are overstated in terms of capacity and others have a relatively short operational life so what started out as a 3000mAh battery quickly degrades to 1000mAh due to chemistry degradationHappy Easter Everyone

author: ToBeFrank
author_rank: Regular Contributor
timestamp: April 22, 2011, 02:55:43 pm
content: Where did you get the new battery? My experience is anything but the OEM batteries are junk, and the OEM batteries are expensive.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 22, 2011, 04:13:52 pm
content: Quote from: ToBeFrank on April 22, 2011, 02:55:43 pmnot mine though. but i agree we have to cross finger on this. for me, it depends on who made it. i got one cloned battery (for camcorder) that has been going strong for years until now (that was my first purchase of that kind of battery). i'm astounded by it, but think i'm going to get the same quality vs price battery in the future? well, i'm not sure but i will have my finger crossed on it (ie i will get the cloned battery next time again).

author: ToBeFrank
author_rank: Regular Contributor
timestamp: April 22, 2011, 04:18:49 pm
content: Quote from: Mechatrommer on April 22, 2011, 04:13:52 pmYou're right. What I meant to say was:for laptops, my experience is anything but the OEM batteries are junk, and the OEM batteries are expensive.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: April 22, 2011, 09:32:33 pm
content: Over on the Linux sometimes the reporting software used to estimate the battery life is faulty and uncalibrated particularly when after-market batteries are involved. I had a machine once that would boot a certain live distro and in it's infinite wisdom, as soon as the desktop came up, thought the battery was critically low and shut down the computer.

author: Sionyn
author_rank: Frequent Contributor
timestamp: April 22, 2011, 10:16:04 pm
content: agree with battery metering on laptopswas thinking old stock too

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 23, 2011, 01:01:45 am
content: Well those ebay Chinese sellers they do offer packages build with batteries that are near to the end of their shelf life.That supposed to be 4 years in total.End so by getting batteries that are chemically active and even unused for two or three years,they have all ready an capacity loss, and what the controller reports its true.Last year I got an similar battery pack for my ACER ,luckily it was getting an 100% fully charged , now it fall at 97% fully charged.And the aging of the batteries it will continue to cripple the pack , slowly but it will continue.The true fresh batteries cost double value than the ones that are 2 years or more chemically active.