# Li-Ion Cell phone battery started to bulge



## alltracturbo (Feb 7, 2010)

Is it common for a 2 or 3 year old Li-Ion cell phone battery to bulge?

I don't use the phone much at all, it mostly sits all day connected to the charger. I was using it last week and actually used it till the battery was almost dead. I was probably on the phone for 2 or 3 hours when I noticed that the flat back plate of the phone felt a little round like it was being pushed out. It was barely noticeable and I thought it might have always been like that and I never noticed it before.

After about another half hour I got off the phone and took the battery out and seen that it was slightly bulging. I wasn't worried about the phone since it was free with my plan and i'm overdue for another free one, so I stuck it back on the charger and the bulge hasn't gotten any bigger since.

I didn't think much of it till I just started reading about lithium batteries and how they can explode. I've probably had the phone for 2 years. There's a number on the back 20070427. I'm thinking that might mean April 27 2007. The battery is a Motorola BT51.

Think it's a bad idea to have these kind of lithium batteries scattered around my bedroom? I have another 3 that I know of that are older than this one just sitting unused. Two of them are connected in old phones that never get turned on.


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## shadowjk (Feb 7, 2010)

I'd seriously consider replacing the bulging battery and not charging it unattended.


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## Bullzeyebill (Feb 7, 2010)

Yeah, too much charging is probably the problem. Lots of people ruin their cell phone battery, and other device batteries by constantly keeping them on the charger. Take out the battery and check the voltage. As a CPF'er and with all of the information available to you here about different batteries available, you should have a DMM, or a good voltage meter. I would not think of using Li-Ions without a DMM to check them out periodically. 

Bill


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## TooManyGizmos (Feb 7, 2010)

Stop feeding it hamburgers , fries and pizza !


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## Apollo Cree (Feb 7, 2010)

Throw the bulging battery away and get a new one. Do it right now. 

Definitely don't charge it unattended. I'd be afraid to charge it or use it at all. 

It wouldn't be a bad idea to put the old batteries somewhere they can't easily start a fire.


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## alltracturbo (Feb 8, 2010)

Why do they have 4 terminals on each battery?

Directly off the charger after it says charge complete, it shows 4.17v. Is that low? I thought I read somewhere that fully charged lithium cells are 4.5v. What should I be looking for? Will it not hold a charge if it is bad?

I'm definetly not going to continue using it. I'll probably order a new phone tomorrow since it's free.




Apollo Cree said:


> It wouldn't be a bad idea to put the old batteries somewhere they can't easily start a fire.


Funny you should mention that. There's 3 locations I can think of in my room right now that has old lithium batteries.

1. One in a dresser drawer filled with all kinds of computer electronics. Not too bad untill I remembered that there is a small ammount of gun powder and a couple Estes model rocket engines in there.

2. One in my closet in a bag right around a bunch of cardboard boxes and about 700 rounds of ammunition.:duh2:

3. And another 7, yes 7 lithium batteries, in a nightstand right next to my bed and ironically 2 of them are right on top of two 50 and 25 foot rolls of cannon fuse. 

And I just remembered there's at least 1 under my bed.


So other than not setting up your bedroom to emmediately engulf in flames if there ever was a fire, what are some basics I should know about lithium batteries? It's a good time to start learning considering I just ordered a LF2XT from kuku with the set of Li-Ion 10440's. I don't wouldn't wan't to do any damage to such a nice light, especially since I couldn't afford to replace it right now. I've been meaning to do some research, but haven't gotten around to it yet.


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## alltracturbo (Feb 8, 2010)

I just found a good thread.

https://www.candlepowerforums.com/threads/213738



1dash1 - From link above said:


> You've already taken some right steps: purchased high quality li-ion cells, using a charger that is dedicated for charging 10440's, pulling the cells as soon as the light turns green, and are applying the cells in an application with a discharge protection circuit. Most importantly, you are alert for the potential danger.
> 
> Other prudent measures:
> 
> ...


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## carrot (Feb 8, 2010)

If you have it sitting around all day being charged it is probably so full of electrons that it has increased volume and mass! :tinfoil:


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## shadowjk (Feb 9, 2010)

I had a dodgy cellphone battery. The worst behaviour (heating) came during charge from empty. Once it reached full the device let the voltage drop from 4.2V to 4.0V before it topped up to 4.1V and then let it discharge to 4.0V. It seemed pretty stable and cool in this mode, but recharging from 3.5V made me scared.


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## TranceAddict (Feb 10, 2010)

it is not advisable to keep the charger connected all the time as when li-ion remain in 100% charged, its chemistry will deteriorate very fast.

charging a bulged cell (if it is original OEM) doesn't sounds too risky, under the battery terminal there is a protection PCB with over voltage/current and thermistor for thermal cut-off, and a vent hole just beneath it, in the worst case i have seen many times it just become permanently opened-circuited.
but there is no point to continue to use the cell as its capacity is just so low could last for a short while only.


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## shadowjk (Feb 10, 2010)

TranceAddict said:


> it is not advisable to keep the charger connected all the time as when li-ion remain in 100% charged, its chemistry will deteriorate very fast.



This depends on the charger, of course. The charging chips in all of my Nokia phones stop charging when the battery is full. It does a partial recharge again after a few hours. After the initial peak full charge, the battery is never again charged to full unless you replug the ac/dc adapter.


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## alltracturbo (Feb 10, 2010)

I didn't know much about lithium batteries and didn't think it would matter. Just figured it kept it on a trickle charge and would be fine.

So I guess that it's a bad idea to do that with a laptop too then. My laptop is used mostly like a desktop and is almost always plugged in.


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## shadowjk (Feb 11, 2010)

The heat in the laptop also has as big an effect.


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## 45/70 (Feb 11, 2010)

While not having any experience with LiPo packs, from what the R/C folks say, your battery is beyond dead, as well as being a potential hazard to you and yours.

Also, I'll point out that the most damaging SOC (state of charge) for any Li-Ion chemisrty battery pack, or cell, whether LiPo, LiCo, LiFe, or LiMn, is nearly discharged, or fully charged. If you keep your laptop, or other device plugged in to the AC all the time, you're guaranteeing an early demise for your battery pack. Keeping Li-Ion's in a nearly discharged state, or fully charged state promotes faster oxidation of the electrodes within the cell. This why a 40% SOC is recommended when storing Li-Ion battery packs and cells. 

Dave


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## alltracturbo (Feb 11, 2010)

It would be nice if there was an advanced battery option on the laptop to set what percent you wan't the battery to stop charging at. That way if you use the laptop plugged in all the time the battery will last longer. If you plan on using the battery you can just tell it to do a full charge. It sounds like it would be a very easy program to make.


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## Quension (Feb 11, 2010)

alltracturbo said:


> It would be nice if there was an advanced battery option on the laptop to set what percent you wan't the battery to stop charging at. That way if you use the laptop plugged in all the time the battery will last longer. If you plan on using the battery you can just tell it to do a full charge. It sounds like it would be a very easy program to make.



It's not; it's entirely dependent on BIOS, as it's responsible for the charge controller. Usually if adjustments are at all possible, they're configured in tools provided by the laptop manufacturer. I've seen an IBM (Lenovo) with this option, but not many others.


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## Bright+ (Feb 12, 2010)

alltracturbo said:


> Why do they have 4 terminals on each battery?



Most lithium-ion battery packs have at least 3 terminals for monitoring purposes. Obviously, + and - for power and third terminal for temperature sensor that shares the ground with power. 4 terminal version may use a temperature monitoring that doesn't share terminal with power terminals, or it maybe for another purpose (i.e. different resistance based on pack specs to tell the device what the cell is for example 10kohm for normal, 25 k ohm for extended capacity) 

Smart battery packs will often have even more terminals for accessing internal metering chip which provides the device with a quite accurate remaining capacity. These are devices that provide reliable remaining charge in percent, such as PDAs and laptop computers. Devices that simply display 1/4, 1/2, 3/4 and full usually don't use this technology


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## alltracturbo (Feb 12, 2010)

Bright+ said:


> Alltracturbo said:
> 
> 
> > _Why do they have 4 terminals on each battery?_
> ...


:thanks:






Quension said:


> Alltracturbo said:
> 
> 
> > _It would be nice if there was an advanced battery option on the laptop to set what percent you wan't the battery to stop charging at. That way if you use the laptop plugged in all the time the battery will last longer. If you plan on using the battery you can just tell it to do a full charge. It sounds like it would be a very easy program to make._
> ...


I still don't see what would be so hard about it. The BIOS controls the voltages of the cpu & ram, the rpm of certain fans, and the rpm of the hard drive. There are simple programs that will let you change all of these options with the computer already running and not having to enter the BIOS. Why would the charge controller be any different?

I don't know if it would be possible for anyone to make. I was actually thinking that it would be easy for the computer or motherboard manufacturer to make and that they should already have that option in current laptops. Guess I should have made that clear in my first post. If they have the ability to detect the battery voltage and can tell it when to stop charging, it should be real easy for them to write a simple program where the user can define what voltage to stop charging at (or percent of charge).


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## Quension (Feb 12, 2010)

alltracturbo said:


> I still don't see what would be so hard about it. The BIOS controls the voltages of the cpu & ram, the rpm of certain fans, and the rpm of the hard drive. There are simple programs that will let you change all of these options with the computer already running and not having to enter the BIOS. Why would the charge controller be any different?


The _chipset_ controls CPU and RAM voltage. There are only a handful of chipsets out there and most of them implement such controls in a standard configuration method that software can access directly. BIOS simply sets some default parameters on startup. The chipset manufacturers provide documentation and demo software for developers (including the BIOS writers), and in most cases it's either already public or available on request.

Fan speeds in consumer-class hardware are usually controlled with a few support components attached to chipset interfaces. It sometimes requires more work to determine what the popular support components are, but there's usually enough documentation out there.

I assume you mean the noise control settings for HDDs, which usually change head seek behavior but can vary RPM on some newer drives. The actual control of that is done entirely by the HDD itself, with the configuration for it available via the same I/O interface everything else uses, and thus accessible to software. Again the HDD manufacturers have to make documentation available for developers if it is going to be taken advantage of, and again in most cases it's accessible to anyone who wants it.

The charge controller, on the other hand, is usually _not_ a piece of equipment that is addressed via standard software-accessible means. Configuration for this component, along with several others in a modern laptop, is usually done via SMM, which is a protected environment that only BIOS can access directly. Not "directly" as in "only the BIOS firmware knows how to do it" -- "directly" as in "restricted by hardware and only BIOS is allowed". Anyone who wants to change parameters on the charge controller has to do it via configuration methods exposed by BIOS itself, if it's configurable at all. There are no standards for this.

Server-class hardware often runs things like fans from dedicated microcontrollers that are also configured out-of-band this way, for reliability reasons.



> I don't know if it would be possible for anyone to make. I was actually thinking that it would be easy for the computer or motherboard manufacturer to make and that they should already have that option in current laptops. Guess I should have made that clear in my first post. If they have the ability to detect the battery voltage and can tell it when to stop charging, it should be real easy for them to write a simple program where the user can define what voltage to stop charging at (or percent of charge).



The ones that control everything in-house and want to provide this option (e.g. IBM/Lenovo) already do. The cheaper manufacturers don't necessarily have the in-house skillsets to do this, so it wouldn't be easy for them even if they had the desire. Note that by "cheaper", I mean the ones that tend to stick close to prototype/demo hardware layouts and mostly-stock BIOS code.


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## alltracturbo (Feb 13, 2010)

Thanks for clearing that up Quension, I think I understand now.

Phone is not a problem anymore. I got another battery (same one) from a family members phone that they don't use anymore. Now I just have to figure out where to dispose of this battery.


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## snakebite (Feb 13, 2010)

the li-ion cells in my kenwood th-f6 pack look like rectangular barrels now.got to take pics before i toss them after i rebuild the pack.


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