Restoring Laptop Battery?

I have Thinkpad T23 purchased about 15 months ago. The batter now only lasts for an hour. It used to last more than 3 hours when new. Even though the Thinkpad is still under warranty, the battery is covered only for an year. A new battery would be more expensive than what this laptop would fetch on E-bay :-(

The battery shows under 70 cycles.

Is there any way to revive this battery? Any suggestions will be welcome.

Thanks,
- Vikas

I don't know of any way to revive lithium ion batteries, but I think you are exaggerating the cost of a new battery just a little.

Batteries are a commonly purchased accessory for laptops, and while they aren't dirt cheap, they certainly aren't so expensive as to make you want a new laptop..

A quick look on IBMs web site shows the replacement battery for a T-series Thinkpad to be US$189 - you may be able to do better through a dealer, or even a third party battery.

But I'm pretty sure a T23 is worth a lot more than $189, even on Ebay.

Here is a link to the T-series battery page on IBMs web site.

Graham

Vikas -

Is this your battery:

http://shop.store.yahoo.com/impactcomputersmiami/02k6649.html

$87 + s/h (looks to be under $10)

Hey, I'll buy your laptop for $100!

John

Yes, I am exagrating little bit but we all know how laptop prices tumble as soon as you buy one

Mine is actually a T20 (not T23 as I had posted in the original topic) 700/12G/128MB/DVD/14"/W98 and yes it is worth more than couple hundred bucks.

Thanks for the pointers to cheap batteries. I will take a look at them.

Any tips on preserving the LiFe batteries? The laptop had moderate use and was mostly used on wall power.

- Vikas

Well, it's worth a try of running it down all the way, then letting it charge up for 8-10 hours, and repeating 2-3 times. For li-ion that came with my last notebook computer, that was the recommended procedure when using for the first time. Not sure if it's memory, or cell depression, or overcharge, or what, but the symptoms are the same. Good luck, can't hurt!

Lithium Ion's don't have the memory issues that NiCd's and NiMH's do.

Are you SURE you have a Li ion?

BTW: Cheapest Laptop Batteries are Double A's, used in a Psion 3 or 5.

The run them down and charge them up doesn't do anything to the battery. It just calibrates the chip in there that keeps track of power in and out of the battery so that the computer can give you an estimate of time remaining and go to sleep before the battery falls off completely.

If the battery voltage drops too far then that chip can get confused and one full cycle will restore it. So it may be that your battery just THINKS that it's out of power and shuts down, when in reality it is not.

There is no way to recondition a LiIon battery AFAIK. They are good for a finite number of cycles and slowly diminish. But it's hundreds of cycles. I use the battery in my powerbook about half way down and back up every day at least once, sometimes twice and I still have about 85% of the original capacity in an 18 month old battery.

If you aren't using your laptop on the move, then probably the best way to extend the battery life is to remove the battery entirely and leave it out unless you actually need to use the laptop away from the main power.

For information on the memory effect in batteries, there is an interesting article here.

Graham

That's what I do with my X20 unless I'm plugged in at a location that I need the benefit of a UPS. With the Thinkpad, it has some hysteresis built into the charging circuit, so it won't continually top off the battery until it drops below a certain level. Generally, I'll run it without the battery installed to save on the cycle counts- luckily Lithium Ion batteries have good charge retention, so I can count on the battery being charged when I do need it.

Originally posted by Graham:
If you aren't using your laptop on the move, then probably the best way to extend the battery life is to remove the battery entirely and leave it out unless you actually need to use the laptop away from the main power.
Graham

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>Are you SURE you have a Li ion?

Definitely :-( The design capacity of this battery is 38Whr. Mine shows up anywhere from 24Whr to 29Whr. Even those numbers seem to be wildly optimistic as I can rarely get even a full hour of usage on battery.

Are there any ill-effects of running down Li ion completely? There are lots of conflicting advices over internet about laptop batteries. Lot of them do not make distinction between NiCd, NiMh or LiFe.

Thanks,
- Vikas

Originally posted by Graham:
If you aren't using your laptop on the move, then probably the best way to extend the battery life is to remove the battery entirely and leave it out unless you actually need to use the laptop away from the main power.

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<font size="2" face="Verdana, Arial">So true! For me the batteries only last a year(or less) if left in the laptop - 3years or so if only used when needed.

Hi Vikas,

That depends on your definition of "completely". 0% state of charge is OK but 0 volts is not. MOST devices with Lithium batteries have a cut-off circuit to prevent over discharge. Nicad and N-Mh benifits from an ocasional discharge to 0% state of charge (about .9 volts per cell). Lithium does not benefit from that type or discharge but some of the battery "fuel gauges" need a discharge to 0% to reset themselves every once in a while. We have a $5000 oscilloscope with Nicads that needs to be discharged about once a month or the "fuel gauge" never reads over 75%.

Ron

Originally posted by Vikas Sontakke:
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Are there any ill-effects of running down Li ion completely? There are lots of conflicting advices over internet about laptop batteries. Lot of them do not make distinction between NiCd, NiMh or LiFe.

Thanks,
- Vikas

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