Comments on: Reviving Laptop batteries

By: » Tips for reviving laptop batteries o5 Recipes for Life

» Tips for reviving laptop batteries o5 Recipes for Life — Sat, 04 Jun 2011 10:37:42 +0000

[...] it away and buy a new one without thinking about reviving the battery. The common belief is that reviving a laptop battery takes a lot of time and effort. But the truth of the matter is that reviving a battery is not that [...]

By: Charlie

Charlie — Sat, 07 May 2011 11:49:08 +0000

Dell pacino is the printed text on the PCB, i looked it up and got the circuit diagram of the entire computer (simular model). turns out, that SysPres is the pin that is connected to GND, (the pin i have called RES)

By: Charlie

Charlie — Sat, 07 May 2011 10:56:42 +0000

cont’d
battery model KM973, 85Wh pins: (written inside)
P-,P-,AL,RES,PRS,DAT,CLK,P+,P+ (AL could be the switch? doesnt work now…) named: DELL PACINO
probably could use these cells, reconditioned, with the new one…. mmmm 9+9 Cells… (or 9+6).
Cb.

By: Charlie

Charlie — Sat, 07 May 2011 10:39:34 +0000

i tried it on a dell studio 1737 and ended up totaling it…
how to switch the battery on is not addressed in this article, so i tried ptting in the pc and having wires going out to the bulb, but it would only discharge to 8.50v (originally 11.1v, target was 5.55v) before the computer would switch it off. so i tried wireingit up, isolating the battery output from the computer with the bulb on the battery, and current still transferred through the existing wires and killed stuff (the light was definately dimmer here and blinked, going out for progressively longer periods till dead), tried a 9v battery on the laptop side to get it above 8.5v but it was loaded heavily.

here says to GND the switching pin to turn it on ( http://batteryuniversity.com/learn/article/how_to_repair_a_laptop_battery ) but if all else fails, drill a hole in each side of battery, to discharge it, mine is an extra capacity type, the extra “foot” side of the battery i have is empty - but this is the negative side so socket can be used instead, with one hole on the other side..
this has three cells in paralel, and three of those in series, nine total.
finally tried to hard reset the battery hardware (disconnect GND) and it didnt recover (it has lights on the battery, these dont work at all now, before it gives a 10101 signal with the 5 leds now nothing)

cb.

By: jerryk

jerryk — Sun, 27 Mar 2011 13:53:09 +0000

Here’s a refinement of this technique - I couldn’t find any 12V lightbulbs in my junkbox, so I made up a load
of resistors in parallel. In series with this load, I put a string of forward biased silicon diodes - the same number of diodes as the # of cells in the battery. So, for my 8-cell battery, I put a string of 8 diodes in series with my resistors. The 8 diodes conduct until the voltage across them gets to less than .6V per diode - then
the current through them falls off precipitously.

The value of this arrangement is that the discharge doesn’t need to be babysat - just hook it up and come back later in the day! I used 10 470-ohm resistors in parallel, which gave me a discharge current of 190mA. When the battery voltage gets to 6V, the diodes just stop conducting.

The resistors I used were 1/4W - If I was going to go buy resistors, I would have bought 1/2W - they get
pretty hot. Hot enough to burn, ouch!

A disadvantage of the diode string is that the current rate will fall off pretty fast as the batteries get close to the target voltage. If I was impatient, I’d want something that pulled full current until it got to that voltage,
then suddenly shut off. And beeped!

By: oogabooga

oogabooga — Wed, 02 Feb 2011 01:16:44 +0000

As others have said, for Lithium batteries, the only way this could be helpful is for rebalancing the monitoring circuits. An interesting theory I heard recently, though, is that keeping lithium batteries cool makes them last longer. i.e. keep them in the fridge (NOT freezer) when not in use. You have to watch out for condensation of course (ideally in a vacuum sealed bag or something), but I’m giving it a shot with my camera and laptop spares. I’d be interested to hear others results too…

By: sb

sb — Sun, 05 Sep 2010 15:00:08 +0000

Hi, at the risk of sounding dumb, how do you output the information from the soiftware

By: samsung smx-f30 charger

samsung smx-f30 charger — Tue, 10 Aug 2010 06:16:27 +0000

to check my battery status via terminal and I googled around looking for a solution. I found the following website explaining in a pretty good way “How to check your battery status in Console”..Just like

By: Mike

Mike — Wed, 04 Nov 2009 01:17:49 +0000

The freezer trick is for a battery that has an internal short due to metallic crystal growth that happens over time with charging. Eventually, you may get metallic crystals form a bridge between electrodes of a cell which turns it into a short circuit - doesn’t give power and doesn’t take a charge.

By putting a battery in the freezer, it is HOPED that the physical contraction of differing materials will fracture these metallic bridges and allow the cell chemistry to operate again. If this doesn’t happen in the freezer, then I’ve heard you should try smacking the frozen battery pack against a hard surface so the shockwaves do the fracturing.

With multiple cell battery packs, you can’t really tell the right thing to do - as each cell could have its own problems that require different treatment - so whatever you try should be done with care and low expectations.

But, you will either (1) Be successful (to varying degrees) (2) Make no difference or (3) Make worse or TOTALLY kill your battery pack.

The deep cycle technique (described by the OP) is quite good if applied to the right battery in an appropriate condition - but it’s no silver bullet and still requires a bit of care to do it right.

By: Rob

Rob — Mon, 12 Oct 2009 21:43:49 +0000

Can anyone confirm this works on Li-ion batteries? Surely this is a bad idea as li-ions will be rendered useless if taken too low, and in a series pack without monitoring each cell individually during the discharge this is likely to happen.
I can see this could help balance the pack, which could improve its overall capacity. If this is the case, i’d recommend discharging each cell individually, monitoring its voltage, not letting it drop below 2.5 volts per cell.
This article appears to be written with NiMh batteries in mind, but don’t want to dissuade anyone who wants to experiment.
Charging Li-ion batteries in a possibly damaged state or without a BMS (battery management system) CAN EASILY CAUSE A FIRE that also gives off very toxic gasses. So do it outside on a long lead with a powder fire extinguisher and the power switch to hand.

From the guy who builds electric vehicles and who’s home recently burnt down.