Batteries are charging and discharging sequentially

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Lmax · #1 Post by **Lmax** » Sat May 22, 2004 1:44 pm

Sorry for the new thread but I have one more question about my new T41p. I have the slim li-polymer battery along with the main battery of course. And I was running on battery power from full charge on both. It looks as though the Slim Li discharged first without even the main battery going down as much as a percent. The Slim Li is completely drained to 0% now and the main batt is on 96%. I just pluged the system back in and am trying to charge it back up, but it appears that it is waiting for the main battery to charge before it starts to recharge the Slim Li-Ploy one.

Well, this is a bit frustrating because I would perfer that the batteries drain simultaneously instead of one right after another. I would think it would be bad for the slim battery to deep discharge everytime I want to use it. Also it doesnt seem like the slim li is recharging at all now, and the battery status says it is not active but it is firmly seated in the bay. Did I damage it or something? It was working yesterday. Or do I just have to wait for the other battery to fully charge?

I would like for them to charge and discharge at the same time. Any help on this issue is much appreciated.

Max

Txiasaeia · #2 Post by **Txiasaeia** » Sat May 22, 2004 1:46 pm

Did you condition them separately or at the same time? EDIT: batteries are li-ion. I am a goof. Conditioning not good for li-ions, don't try this at home.

Lmax · #3 Post by **Lmax** » Sat May 22, 2004 1:48 pm

What do you mean? Yesterday, I put both in and charged them fully. Last night I used the computer and the slim li discharged fully. Now the slim li is doing nothing.

Max

Txiasaeia · #4 Post by **Txiasaeia** » Sat May 22, 2004 1:58 pm

Lmax wrote:What do you mean? Yesterday, I put both in and charged them fully. Last night I used the computer and the slim li discharged fully. Now the slim li is doing nothing.

Max

Oh dear. Take a look at this link:

http://www-3.ibm.com/pc/support/site.ws ... NQJN#Battc

For some reason I thought that these batteries were not lithium ion, but I guess I was wrong. Forget about conditioning. Anyway, you're not supposed to let li-ions fully discharge. Man, I don't know what you should do about this! Refund? I'm pretty sure that once a li-ion is discharged it's toast, unless somebody knows different?

Lmax · #5 Post by **Lmax** » Sat May 22, 2004 2:01 pm

It is not a Li ion that discharged fully it is a Li Polymer, different. I think it will be ok I am going to leave it charging for a while and see what happens. Hopefully it will start charging again.

Max

Txiasaeia · #6 Post by **Txiasaeia** » Sat May 22, 2004 2:07 pm

Shows you how much I can read

Li-polymers *should* be okay to fully discharge, but it's not recommended as it can lower the life of the battery. Maybe give it a rest for a few hours and try again? Since it's very new tech, there's not a lot of info about it, but it still might be a good idea to give IBM a call and see if they recommend anything. Good luck!

Lmax · #7 Post by **Lmax** » Sat May 22, 2004 2:52 pm

Well, Txiasaeia, I think I am in the clear. I turned the ThinkPad off for about an hour and left it plugged in, the li poly is recharging now, it's up to 30%. Whew, (wipe the forehead), I was worried I had toasted it.

I still wish both batteries charged/discharged together. Nevertheless, last night using the two batteries I was able to use it for more than 8 hours then and this morning, before plugging in, and even then the main (high capacity battery) wasn't even down to 60%. I never anticipated this kind of battery life from a p model, or even a regular model. I am quite impressed.

Max

Txiasaeia · #8 Post by **Txiasaeia** » Sat May 22, 2004 2:58 pm

GREAT news! Are there two separate battery meters for the two batteries? If so, I guess you could pull the li poly before it hits 0 and keep on going with the main system battery, but you're right, this must be extremely frustrating. It's good to know this; I'm sure other people appreciate the info. I know I do!

I wonder if there's any info that IBM has on this... even alternating batteries every hour would help this problem and wouldn't place the li poly in "danger," right? Maybe some info came with the notebook/extra battery? I've looked through IBM.com but haven't found any info.

JHEM · #9 Post by **JHEM** » Sat May 22, 2004 3:19 pm

Max,

Lmax wrote:It is not a Li ion that discharged fully it is a Li Polymer, different. I think it will be ok I am going to leave it charging for a while and see what happens. Hopefully it will start charging again.

Yes, it should start charging once the primary battery is at 100%.

They discharge and recharge sequentially by design.

Regards,

James

Lmax · #10 Post by **Lmax** » Sat May 22, 2004 3:24 pm

Txiasaeia wrote:GREAT news! Are there two separate battery meters for the two batteries? If so, I guess you could pull the li poly before it hits 0 and keep on going with the main system battery, but you're right, this must be extremely frustrating. It's good to know this; I'm sure other people appreciate the info. I know I do!

I wonder if there's any info that IBM has on this... even alternating batteries every hour would help this problem and wouldn't place the li poly in "danger," right? Maybe some info came with the notebook/extra battery? I've looked through IBM.com but haven't found any info.

Ooo

good idea I am purusing the book that came with the li poly now. I find that it would kinda be a hassle to have to worry about taking the battery out before it hits 0, if I am working on a paper or book and am typing away I don't really want to sit there and monitor WTH my batteries are doing.

Ok, the Li Poly "users guide" says nothing about the battery itself, all it gives are explosion warnings and warranty info, it is thick because it contains the same thing in over and over in about 50 different languages.

I will see what the HMM or the tabook says and get back to everyone on here.

Max

Lmax · #11 Post by **Lmax** » Sat May 22, 2004 4:03 pm

Ahh, thanks James. One thing I must ask, does the fact that my li polymer battery discharges fully everytime damage the battery, or can I do this everyday and not worry about it and just recharge it at night when I get home from working out in the field?

Thanks,
Max

akerman · #12 Post by **akerman** » Sat May 22, 2004 5:02 pm

Lmax wrote:Ahh, thanks James. One thing I must ask, does the fact that my li polymer battery discharges fully everytime damage the battery, or can I do this everyday and not worry about it and just recharge it at night when I get home from working out in the field?
Max

I'd also like to know about the differences between Li-Ion and Li-Poly!
By the way - a full discharge (conditioning) won't in any way ruin a Li-Ion battery to the point of it being toast. Some people even recommend it (IBM too?) while some say it's a no-no. In my experience, conditioning a li-ion battery lowers its maximum capacity, so I'm not doing that anymore =)

I've also noticed that the main battery doesn't charge beyond 98% sometimes - I think this is mentioned in the manual. If you want it to charge beyond 98%, try turning off the computer, and it should go to a 100%.

geobel · #13 Post by **geobel** » Sat May 22, 2004 5:35 pm

I'd also like to know about the differences between Li-Ion and Li-Poly!

Li-ion and Li-polymer use exactly the same technology except that Li-ion has liquid electrolyte whereas Li-polymer has gel-like, almost solid electrolyte. Li-ion are cheaper to produce and have lower internal resistance but it is difficult to make Li-ion battery flat. On the other hand Li-polymer can be any shape. Handling rules are exactly the same for both batteries. Check http://www.buchmann.ca/ for more info.

Gosha

akeskira · #14 Post by **akeskira** » Sat May 22, 2004 6:15 pm

Both lithium ions and polymers have been used in cell phones for years. Nokia alone has sold tens of millions of them, i.e. lots more than any laptop manufacturer. The technology is mature for sure. Both li-ions and polys can be fully discharged and charged or partially discharged and charged without any worries. The biggest difference between them is that ions require "regular" cells whereas polys can be molded and can thus be of almost any size and form usually giving them higher capacity as the space of the battery module can be used more effectively.
I usually replace my Thinkpads after 18-24 months, and never worry about the battery. I haven't noticed much degradation in the chargeability during that time.

Antti

akerman · #15 Post by **akerman** » Sun May 23, 2004 5:05 pm

akeskira wrote:(editing quote for the sake of nonny)
Both li-ions and polys can be fully discharged and charged or partially discharged and charged without any worries.

This is fuel for a lot of discussions around the web. I've heard from an engineer, who worked with developing Li-Ion batteries, and he fiercely recommended against discharging your li-ion batteries. Then on another board, there was another engineer, working for another company, who said the opposite!

akeskira · #16 Post by **akeskira** » Sun May 23, 2004 5:25 pm

This is fuel for a lot of discussions around the web. I've heard from an engineer, who worked with developing Li-Ion batteries, and he fiercely recommended against discharging your li-ion batteries. Then on another board, there was another engineer, working for another company, who said the opposite!

Whichever is correct, isn't the sole purpose of a battery its ability to provide with electricity while not plugged in and thus discharge regularly. IMHO, there is no point of buying a fancy laptop with low power consumption and a good battery if the owner doesn't dare to use them... This is especially true with Thinkpads - they're tools, designed for heavy daily use.

Antti

krosenstein · #17 Post by **krosenstein** » Thu May 27, 2004 12:57 am

I found this site to be very informative.
http://www.batteryuniversity.com/partone.htm

#18 Post by **JaneL** » Thu May 27, 2004 6:53 am

>Whichever is correct, isn't the sole purpose of a battery its ability to provide with electricity while not plugged in and thus discharge regularly. IMHO, there is no point of buying a fancy laptop with low power consumption and a good battery if the owner doesn't dare to use them...
>

That's always been my philosophy. Batteries are disposable; data is not. It's almost like getting a flashlight and batteries and never lighting it up. What's the point?

akerman · #19 Post by **akerman** » Thu May 27, 2004 12:38 pm

There is a difference between using them, and deep discharging them.

Batteries are charging and discharging sequentially

Batteries are charging and discharging sequentially

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