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Pismo Battery Reset/Recondition/Resomethingtomakeitworkagain

MultiFinder

Well-known member
I just got myself a Pismo (poke around conquests :D ), and my only problem with it is that the battery is flat as a board. It shows up as empty and fully charged; if I pull it out and shove it back in, it shows the lightningbolt charging symbol, then goes back to fully charged (but still quite empty) after just a few seconds. It won't last any time at all; unplug the mains, and the lappy dies.

My google-fu seems to have failed me on my quest to answer this question: Is there any way to get this Pismo to start charging that bloody battery? I've reset the PMU, PRAM, everything that can be reset, still to no avail. If any of you have any suggestions on how to get it working again, beyong just recelling or buying a new one, it would be most appreciated. Thanks :)

 

Franklinstein

Well-known member
LiIons are a pain. I've got some for my 3400 and 2400 that still hold at least an hour's charge, and several for Lombards/Pismos/iBooks that are dead as hell.

I'm pretty sure that it's not entirely usage that's to blame, because I've had flat-dead, unused-for-months 2400 batteries come back where partially flat 2-days-out-of-service Lombard batteries would do nothing but provide endless aggravation by not charging or by randomly dying with varying charge levels remaining displayed.

I like to blame it on the relentless march toward more in the same/smaller package: with a higher battery capacity, it seems that service life/cycle count is markedly reduced. I personally would rather lose an hour of runtime than have to replace the damn $150 battery annually, but nobody asks me.

Anyway, the only real idea I've had is cracking the battery pack and desoldering the battery leads from the main PCB to force-reset the "smart" electronics onboard. Of course, those boards (and most other LiIon battery-based things) also have a "if the battery goes below X charge, DO NOT EVER RECHARGE AGAIN!" feature, which is irreversible once set. This safety is apparently to keep the batteries from exploding or whatever, but they seem to do that of their own accord anyways, so I don't see how it helps. But yeah, I tried this once, and it didn't help, so I got a new battery; recelling LiIons is often more trouble than it's worth, particularly with aforementioned safety.

 

tomlee59

Well-known member
You have taken all of the normal steps to revive a dead battery. Regrettably, it is no more. It is pining for the fjords. It is an ex-battery.

Re-celling a lithium-ion battery is not without serious risks, and therefore not recommended casually (if at all).

Replacement is your only practical option.

 

Unknown_K

Well-known member
I recently got in 3 dead wallstreet batteries (2 Apple made and one 3rd party). One of the Apple batteries charges in like a few minutes to 4 lights and will not boot a machine. I expected a used up battery to charge quickly but provide no power, being used up. My question is what would cause a battery to not even show up when connected? The other 2 batteries do not show up when inserted, ofcourse no lights come on when I hit the button either. Since those batteries do not show up they do not get charged (x over the battery icon). I never seen a completely dead battery like that, is there something disconnected inside by chance, battery leaked and killed the wiring?

I knew the batteries were dead when I got them, just wanted something to fill in the holes on a couple wallstreets I have (currently have 5 units and 3 good batteries between them).

 

wally

Well-known member
Upon battery insertion the battery manager board, if working, momentarily test charges the cells and looks for approximately

3V=

If this is not met charging is disallowed and the battery would not be recognized nor connected to the laptop for discharge. Of course if the battery manager itself was toast that would do it also.

Cells that have been discharged down to the normal 3.0V cutoff point normally rebound to about 3.4V or more within minutes of being disconnected. Cells that measure much below 3V are approaching a dangerous chemical state internally for later internal shorts should they be subsequently recharged and are best never used again.

The laptop batteries commonly use a series parallel configuration that requires a degree of cell matching to be safely charged and discharged. Cells from different manufacturers use different forms of carbon inside and have correspondingly different charge control parameters programmed into the battery manager EEPROM. There needs to be sufficient current sharing within a paralleled group so that the high current intended for the paralleled set does not inadvertently flow thru just one cell (as it could from mismatching or if cell strapping fails) and make a bomb. To make the gas gauge work right the groups need to have reasonably comparable amp hour capacities and internal series impedances. So recelling especially using used cells requires instrumentation, bench measurements, cell matching and a properly working battery manager, not just flawless connection technique rewiring charged cells. If the safe operation zone specified in the cell manufacturer's datasheet and application notes is exceeded for any reason you have a potential incendiary bomb that can also vent boiling alkali steam and blind someone.

 

tomlee59

Well-known member
Thanks for that, Wally. It underscores how much more there is to fear from mistreated lithium cells than from the LHC. ;)

 

Unknown_K

Well-known member
So basically the cells are dead and the memory manager will not let the unit charge at all. There is no problem then using the battery as a space filler in the laptop (which is the reason I wanted them)?

 

wally

Well-known member
I think the filler is useful to give the laptop increased mechanical stiffness and better balance. And the primary hazard is with charged cells. However uncharged batteries still might have some charge in sections (and hold it for a year or so), and in any case there is a lot of lithium chemical in various forms inside which will not appreciate any moisture from the air leaking in there long term. The risk is not zero. The risk of a filler is smallest if handled gently, avoiding mechanical shocks AND if the laptop NEVER tries to charge it while it is left plugged in. Some batteries have shorted/leaked from being dropped, and the higher capacity versions in a given cell case size are more vulnerable to damage from mechanical shock. An even better filler would be one with no cells and no battery manager board, just the case with stiffening weight inside. You'll have to decide for yourself; I admit to being paranoid about Lithium Ion, and store mine in my fireplace when I'm not in portable mode. Here is why:

A lot of folks are working on safer battery chemistries for portable power and vehicle propulsion. Many of them use the original Sony Lithium Ion battery technology performance, in the 18650 size used in our laptops, as a reference to show just how improved their new thing is in comparison. The next new thing may not be perfect, so how great to have something really bad to compare against...

Several comprehensive studies by Sandia Labs shows that the Lithium Ion charged cell has a thermal runaway problem that can be triggered by temperature alone. Additionally, old cells that have increased cell resistance and uneven current distribution will develop hot spots during use that will further decrease the critical environmental temperature needed to initiate runaway under in use conditions. Soldering can easily exceed the trigger temperature even with zero current flow and a short during soldering, well that could be really exciting.

If you have a high speed connection and want to work on your PhD in batteries, see the highly technical details at:

http://www.osti.gov/bridge/product.biblio.jsp?query_id=0&page=0&osti_id=918751

(3.7 MB pdf download)

http://www.osti.gov/bridge/servlets/purl/921604-QQEfTo/ (2.5 MB PDF download)

Should thermal runaway occur you will not be able to stop it with anything commonly available in households. Not only will the first runaway cell burn to complete destruction, it will most likely heat adjacent cells enough to serially cook off the remainder, slowly at first, then a big fireball.

See the video at

http://www.valence.com/technology/safety_video.html

for what this looks like. Now they started this runaway in a non-conventional manner, but however runaway is started, I think this pretty much shows how it propagates. It could easily set a house on fire.

 

Unknown_K

Well-known member
Thermal runaway is kind of rare considering how many batteries are out there and how many combusted.

 

wally

Well-known member
Very, very rare indeed, so you might reasonably conclude that the weight and stiffness are much more valuable to you in stabilizing your laptop than a tiny, tiny risk of fire from unmodified but dead battery leakage. In my case, I have enough weight from a CDROM drive on the other side and do not move my Pismo much except when wardriving. Also I am not concerned with the cosmetics of the open bay nor dust getting inside. Since I cannot test my recelled charged battery to the same degree as a professional battery remanufacturer I'll continue to distrust it more than an unmodified unit. I'm treating it as an experimental project, not a product to be trusted.

Edited post: I forgot to mention the Laws of Batteries: [:D] ]'>

1. Household batteries have corrosive stuff inside.

2. A watched battery never leaks.

3. There is an irresistible force between the corrosive stuff and battery contacts (and also nearby circuit boards).

4. The plating on the battery contacts is no match for the corrosive stuff.

5. Most unwatched batteries try to be good, but the worst are the spoiled ones that are stored in your most prized gadget.

6. There are two kinds of unwatched batteries, those that have already leaked, and those that will.

 
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