Reconditioning a cell phone battery? Is it possible to restore life span?

[Judges]

Reply #5 on: January 02, 2010, 06:35:09 PM »

Thanks,kator01,,,going to give this a try.
Batteries are costly and a nuisance,as,all my hand held equipment runs on them.
Joe.

[infringer]

http://r-charge.com/rc-1au.html

Professional reconditioning charger... Dunno if it operates on the same basis or not but anyhow just thought I would share as an alternative.

[infringer]

LiOn Revival guide: http://sodoityourself.com/reviving-laptop-batteries/

For Info purposes I will add a cut and paste in case the website does not last... Graphs and pics not included sorry.

Here is a way to revive your old battery pack. Usually the laptop battery is the first part to break. On older laptops a new battery pack can cost more than the PC itself, so buying a new one is no option.

I have had different results with different battery packs, but the usual is a 50-70 % increase in time running on batteries. My personal experience is that NiMh batteries are much easer to rejuvenate than LiIon.

There are no guarantees and you might end up destroying your Battery pack. It might even explode, so continue at your own risk.

Step 1 - Drain the battery

Remove the AC adapter and let it run until the battery is completly empty. You can turn off all power saving features to speed things up. When it goes in to sleep mode, try to turn it on until you get no response at all.

Step 2 - Drain the battery even more

Using a low wattage 12v lamp (car brake light for example), you can empty the battery pack even further. Check the voltage of your battery pack, and use a lamp with a suitable voltage. Remember not to use a lamp with too high wattage as this could damage your batteries.  Also, be careful not to short circuit. You will need to figure out where the ground and + voltage is. On this IBM thinkpad batterypack they are located on the opposite corners in the connector.

Connecting to battery using paper clips

Paperclips are ideal to connect the lamp to the battery connector.

Let the lamp shine until you see it going slightly dimmer. It is important not to drain it too much (especially Li-Ion).

Draining battery using lamp

If you are the cautious type, you can hook up a multimeter and measure the voltage. I usually don’t like to bother, but you can calculate how much you can drain (Skip if if you don´t care that much):

For example if your battery has 9,6 Volts printed on it:

9,6 / 1,2 = 8 cells

8 x 0,6 = 4,8 V.

So, it’s safe to drain this 9,6 V pack to 4,8 V.

Step 3 - Recharge

Now it’s time for the for the fun part. I like to log just about everything to track the results. If you like that too, just download and run apmmowin before inserting the battery. The output can be redirected to a file like this:

apmmowin > cycle1.txt

Recharge to 100%, and repeat from Step 1.



Results

For this article i have used apmmowin to log the results. The graph below shows the increase in battery time from 50 minutes to 2 hours and 41 minutes:

Battery graph

These results are from four cycles with a  IBM Thinkpad R40 9.6 V Ni-Mh battery pack.

Before the discharge / Recharge cycles the battery time fell drastically from 60% to 10%. Afterwards the drop has dissapeared and the discharge rate is much more constant.