Test Li Ion Batteries?

Assuming YM laptops.

I have not used it, just know of it's existence. I do like and use their BurnInTest software.

You'll find quite a bit on testing LiPo batteries in the model airplane forums. For example:

If your Li-Ion battery happens to be in a Windoze laptop, I suggest HwInfo32 (or 64) which includes a fairly complete battery capacity report.

If you just want to test the battery itself, I use:

which produces nifty graphs instead of a single number.

If none of these answer your vague question, please disclose what you're trying to accomplish and what you have to work with.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com

You need to be much more specific about what you want to test and why.

I'll use the term "become unusable" instead of "fail" cause lithiums used according to their design specifications rarely "fail". For example, lithium batteries in laptops become unusable because of increased internal resistance. The reduced voltage under peak load causes the protection circuitry to report lower capacity and turn off the system. There may be many watt-hours left, but the protection circuitry won't let you have them. I've taken packs that wouldn't run a laptop for 10 minutes and tested them at lower current. I got almost ALL of the original watt-hours out. I've switched to testing individual cells for internal resistance.

One symptom of this in older laptops is that the system reports 100% charge and starts dropping normally down to some lower level, like 40%, then jumps to near zero and the alarms go off. Depending on the details of the protection, the laptop may run for another hour while reporting near zero capacity.

It's quite possible to correct for much of this, but there are at least three problems.

1) Vendors don't care if you have to buy a new battery...margins are MUCH better. The higher the cost of the battery, the more likely you'll buy a new laptop. I buy used laptops. The cost of a used laptop with a good battery is less than the cost of a new battery. 2) Less complexity costs less and you'll buy the cheaper laptop. 3) Any deviation from the industry norm invites lawsuits if something ever catches fire. Vendors are much more worried about a multi-zillon dollar lawsuit than you being pissed over a $100 battery.

So, the best test is one that simulates the usage. For a laptop, I keep the display on and play mp3's until it quits. How long it runs is ultimately what matters.

Thanks everyone for your comments! Will try to answer each question.

This question was general because my new camera and laptop have Li batteries and while I have a lot of experience with NiCd and NiMH batteries have no experience with Li batteries so would like to learn how to test them and maximize their life expectancy.

JW "Assuming YM laptops.http://www.passmark.com/products/batmon.htm " Thanks for the Passmark tip will try it.

Ken

Hi Jeff,

Thanks for all the links!

The Li Ion battery pack I am most interested in checking is a Toshiba PA2490U (10.8V 3600mAh) While it is new to me the Laptop and battery pack is ~ 15 yrs old.

The only packs I have found are recycled ones

Until I can test these Li Ion battery packs am unable to evaluate them.

Some of the links you provided mention testing each cell of the pack. The Toshiba has 8 connectors between the - & + and 2 more so hope everything can be checked without opening the pack.

Has anyone had experience with these Toshiba Li Ion packs?

Ken

Hi Mike,

Thanks for your comments. Hopefully my previous posts have answered why I want to test Li Ion battery packs.

"I've taken packs that wouldn't run a laptop for 10 minutes and tested them at lower current. =A0I got almost ALL of the original watt-hours out. =A0I've switched to testing individual cells for internal resistance." Hope you have some experience with the Toshiba Li Ion battery packs!

Have done some searches but have not found any info on the pack connectors.

Ken

I have a few of those in the office. After 15 years, most are dead or fairly close to dead. Any of the battery analyzer programs mentioned should give you an estimated capacity. However, the best test is to simply run the laptop on battery and see how long it lasts. If it won't run the laptop, consider it dead.

Check eBay:

Some used battery packs, probably in the same condition as yours.

Those are sensors, protection circuitry, and i/o for the charge controller in the battery back.

Only in replacing them.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com

Hi Jeff,

"I have a few of those in the office. =A0After 15 years, most are dead or fairly close to dead."

Have you opened any of your dead packs? If yes, any tips?

Am wondering if a cyanoacrylate was the adhesive? Have you tried a debonder before opening packs?

=A0

Thanks again for all your help!

Ken

Hi Jeff,

"If you just want to test the battery itself, I use: which produces nifty graphs instead of a single number."

Since you have a number of these old Toshiba Li Ion packs, have you run CBA tests on any or all the working ones?

Ken

Nope. I haven't opened them. I keep a few on hand because some of the early Toshiblah laptops would not run on charger power unless a battery (dead or otherwise) was installed. I'll look at it to see how it comes apart, but I don't want to wreck them.

Dunno. If it was cyanoacrylate, it will be brittle. Beat on the seam with a stiff putty knife and you'll crack the glue joint. That works on some other battery packs I've broken open.

Light reading on killing batteries:

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com

Nope. I'm mostly interested in unpackaged Li-Ion and LIPO unpackaged batteries for model airplane and robotic use. Also, I've tested some cell phone batteries and tested for some oddities, such as NiMH batteries that actually increase in capacity on initial charge. It takes a long time to test a battery properly, so I don't do it often. The bigger the battery, the longer it takes to discharge.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com

I have a similar need for older toshiba packs. Problem with lithiums is that they degrade whether you use 'em or not. Most battery packs you can find today were manufactured about the same time as the laptop. It's unlikely that you'll find anything newer than

10 years old for a 15 year old laptop. I think the only viable alternative is to have the pack rebuilt with new cells. There are people who do that, but it ain't cheap.

It is possible to rebuild them yourself. I bought used spot welder for the purpose. New cells with tabs cost more than a new pack. I tried to use cells from a different good pack. It's a crap shoot depending on the controller design. Some lose their brains when you remove power and it's all over. Others remember the previous capacity, so the new battery won't last much longer than the old one. I've only found one battery pack with a pic processor in it. I managed to reset the pic and recovered it.

In my experience, you can buy a newer laptop with a usable battery at a garage sale cheaper than you can buy a used/bad battery for an older laptop. Even if you do have to buy a battery, it'll be a newer vintage.

AS for the pack connectors, there's almost nothing that can be done from the outside...by design...they don't want people blowing themselves up and suing them. There's data/clock pins that access half of the chip to readout status. There's a different isolated bus inside the pack that can be used to program the parameters into the chip. You have to take it apart, and build an interface. But you still have no idea the data format of what numbers to put in. There's a vendor who will send you the code for a hefty fee per battery.

To get batteries apart, you clamp them in a vise along the seam. Use a sharp wood chisel and a lightwieght hammer. Smack it along the seam. You want high peak force to snap the seam without a lot of mass to penetrate the pack. It's easy to damage the cells or the circuit board, cause the plastic is thin and sits right on 'em. You can't just pull the plastic apart, you have to break the joint. And they're typically glued in, so getting the cells out of the plastic can be a challenge. Be careful where you pry, cause there are thermistors and thermal fuses buried in there.

Bottom line, unless you have a LOT of packs to fix, give it up. Have someone who knows what they're doing, recell it. Or better yet, go to a few garage sales and get a better laptop. People are decommissioning some mighty fine laptops to make room for their shiny new ipad.

Hi Jeff,

=A0"I keep a few on hand because some of the early Toshiblah laptops would not run on charger power unless a battery (dead or otherwise) was installed." =A0

I checked, the old Toshiba LT will run without a battery pack.

The airplane forum link mentioned fires with Lithium Polymer Batteries

Did some searching concerning fires with Lithium Ion batteries and while found mention of this being caused by internal shorts

, have not yet found any mention of this happening to these old Toshiba Li Ion batteries.

I did find a recall of newer Toshiba Li Ion packs (actually Sony Li Ion cells) sold from April 2005 to October 2005

Do you know if the older Toshiba Li Ion packs used Sony Li Ion Cells?

Ken

OK, you win.

There are YouTube videos, showing what happens when you pound a nail into a LIPO battery. To the best of my knowledge, all battery packs that have internal charge controllers include short circuit protection. That doesn't help when metal chips inside the battery cause the shorted battery condition. However, a 10-15 year old battery is unlikely to store enough energy to do much damage.

It didn't happen until Sony produced a large number of potentially defective batteries. The actual number of defective cells was probably rather small, but with the risk of fire or explosion, it was necessary to recall millions of battery packs to find those few.

The web page lists Satellite: A70/A75, P30/P5, M30X/M35X, M50/M55 Tecra: A3, A5, S2 as the models affected. Is your laptop one of those? (Hint: It helps to supply details of what you have to work with).

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com

Hi Mike,

Thanks again for all your comments!

"Problem with lithiums is that they degrade whether you use 'em or not."

Been trying to read everything I can find and came across " Recharging when the battery hits 50% charge is the ideal to maximize its life."

Does this correspond to your experience?

Also have you determined what the Max and Min Voltage should be for Toshiba PA2490U 10.8 V 3600mAh battery pack?

" I tried to use cells from a different good pack. It's a crap shoot depending on the controller design. Some lose their brains when you remove power and it's all over. Others remember the previous capacity, so the new battery won't last much longer than the old one. I've only found one battery pack with a pic processor in it. I managed to reset the pic and recovered it."

Have you posted these Li battery experiences any where? Would be interested in learning more.

The only Sony Li cell test I have found is

and the cell seemed to have been more affected by prolonged deep discharge than overcharge.

Ken

All my batteries come in used computers. I have no knowledge of the history or abuse of them. I've never put enough hours on a single computer to notice any aging effects. I've got so many laptop batteries in my fridge that I'm afraid I'll break the glass shelf.

It varies somewhat with chemistry, but 4.2V seems to be the absolute maximum for cells of that vintage. So, 3 x 4.2 = 12.6V. But you should verify that independently with the vendor to make sure. My lawyer made me say that. Minimum voltage is pretty much irrelevant. When you're using your computer, your priority is to finish what you're doing. Stopping when the battery reaches some voltage is counter-productive. You have no control over the thresholds set inside the battery pack and the computer.

If you want maximum battery life, charge to 30% and put it in the refrigerator. Take it out occasionally and cycle it up and back down to 30%, then put it back into the fridge. Won't do much computing in there, but will last a long time.

Worrying about it in actual use is also counter-productive. Conventional wisdom is to recharge frequently keeping the voltage up near max to reduce damage to do deep discharge. But the forces that cause storage damage increase with voltage, so you should keep the voltage as low as is practical. Can't win there either...conflicting parameters for two different aging forces.

A laptop battery not fully charged when you need it is not helpful.

Keeping the temperature down seems to be the only effective remedy.

nope

There's likely a pressure sensitive switch in the cell that opens and stays open when the pressure exceeds some level. The author's cell probably did not vent. Some people claim that you can reset the switch by poking a probe thru the hole in the + terminal. I was never successful.

I have several Dell 8-cell packs with EVERY cell open. I can understand how more than one might open, but ALL of them at the same time? One opening puts twice the current thru it's paralleled mate which should cause it to open soon. But that should stop the current.

Bottom line...remember your priorities. If you need your laptop, keep it fully charged. Use it when you need it, turn it off when you don't. That's about all you can do.

Has anyone checked what the Maximum Voltage charge is for the Toshiba PA2490U (using older Toshiba LapTops)?

Reason am asking is I recently read "How to Prolong Lithium-based Batteries"

which mentions "Specifying battery life by the number of discharge cycles is not complete by itself; equally if not more important are temperature conditions and charging voltages. Lithium-ion suffers stress when exposed to heat and kept at a high charge voltage....The voltage level to which the cells are charged also plays a role in extending longevity...Realizing the stress on the battery, some laptop and cellular phone manufacturers choose an end-of-charge voltage that is less than 4.20V/cell."

Am wondering how conservative Toshiba decided to be?

Thanks

Ken

Hi Jeff,

"Do you know if the older Toshiba Li Ion packs used Sony Li Ion Cells? The web page lists Satellite: A70/A75, P30/P5, M30X/M35X, M50/ M55 Tecra: A3, A5, S2 as the models affected. =A0Is your laptop one of those? (Hint: It helps to supply details of what you have to work with)."

My model is a Tecra 510CDT.

Also have you found any docs mentioning the Li cell mfr(s) for the PA2490U battery packs?

Ken

You can find that out with a voltmeter. And what are you gonna do about it if you don't like the number?

Life is a GIANT decision tree. At the end of VERY FEW of those branches are things that can make your life better. 99.9999% of those branches are roads to nowhere. Others are roads to disaster. The more time you spend fussing over things you can't affect, the less time you have to travel the roads to the good stuff.

When you need to compute, turn on the computer. When you don't, turn it off. Simple. Is it really worth the possibility of setting your house on fire to make it complicated?