Battery Maintenance - What am I doing wrong?

Hi Guys,

I'm having issues with keeping my T61p battery healthy. I'm not sure what I'm doing wrong, but I keep killing the "Full Charge Capacity" ... I read on some forums that its not good to keep the battery at full charge and constantly charging so I set the following from day 1:



But over time the condition of the battery kept getting worse. My usage of the laptop is pretty much 24/7, and it spends 95% of its time in a dock, I hardly ever shut it down (if I'm going somewhere I will put it to sleep), but I leave it on overnight when I'm not using it. As you can see from the screenshot below, my charge cycle is only 83 and I'm already down to 34% of the original capacity! I've seen others with cycle counts of over 200 and they still have 80% plus of their original full charge capacity... So what is the secret to maintaining a healthy battery, and what am I doing wrong?



Thanks!!

 

Probably bad cells. Get it replaced under warranty if it has been under a year. Also the heat from having it docked can kill a battery's capacity, however it should not be to that extent.

I imagine defective cells.

 

The only thing I can tell you is that my 6-cell T61 battery lasted about 11 months. I now get 10 minutes, maybe 15 off of it. As much as I like ThinkPads, I'm not impressed with battery longevity; the Latitude D630s we use at work have fared far better.

I'm hoping this changes with the T400 I have on order.

 

It's not so much the laptop brand as the battery cell maker. I believe the vast majority of Thinkpad batteries are made by Sanyo, while most Dell batteries are made by Sony (at least that has been my experience with Dells in the past; I haven't had a Dell in a while).

You should probably remove the battery when the laptop is plugged in, as heat is bad for the battery, but it shouldn't have degraded that much with the thresholds you set. Judging from your first-use date, it's been over a year since you got the battery, so I believe it's out of warranty - you'd best find some place that sells replacement Thinkpad batteries for cheap. I know jonlumpkin had a good experience with one of those sites.

 

You can try deep cycling the battery (turn off ALL shutoff timers and low power alarms) and let the machine run until the battery cuts itself off due to low voltage. This can re-calibrate the battery and you may see the charge capacity go up.

However, I believe that jaredy is right and your battery has 1 or more bad cells. You will need to replace it and it is likely out of warranty (manufacture date of 2007-12-7; one year warranty for batteries). I have had good luck with CalCellular and they tend to be less expensive than buying directly from IBM/Lenovo ( $73 for a 6 cell T61 battery).

In the future I would recommend setting charge thresholds if you mainly use it in the dock. Ideally you should keep the battery between 30% and 60% for long periods in the dock.

 

i got some question to the charging issue
if my battery now at 60% is it okay to charge it to 100%?
or should i wait till it's on critical condition (5% or less) then charge it ?

 

I'm gonna have a 6-cell battery in my T400 when I get it, I guess I'm gonna have to learn how to best take care of it so it will last me at least 1 1/2 years, I guess I'll be ready to buy a replacement battery by then...

 

Thanks for the advice everyone...

This deep cycling the battery, is it that same as doing a battery reset (in power manager)?

 

That is fine. Lithium ion batteries don't have a "memory effect" so you don't need to drain them all the way down before recharging (NiCads have this problem). However, it still isn't ideal to be constantly topping it off (i.e. drain to 93%, charge to 100%, drain to 94%, charge to 100%, repeat).

The main idea is to reduce cycle count by setting your start charging base below the default (normal is charge when below 96%, stop at 100%). I tend to use either 50% or 60% as my base, but would recommend you pick a base that is the minimum amount of battery life you feel you require on a moments notice (could be as low as 40% or as high as 95%).

You should NOT purposely discharge a battery just to get it down to a magic number (e.g. 50%) before recharging it. If you need to top your battery off (e.g. before a plane ride) just go into power manager and remove the thresholds.

You can also consider lowering the stop point for the charging cycle. 85%-95% is ideal for normal usage if this provides adequate battery life for you. Li-Ions prefer to not be at 100% charge for long periods of time (this accelerates wear).

All this being said, the rate at which batteries wear is as much to do with luck as anything else. I went through three batteries for my T40 and all of them aged fairly quickly (my most recent one held about 80% of its charge after 9 months use). However, I have had good luck with the battery for my x200 Tablet (60 cycles over 7.5 months and still rated at 101% of design capacity [it arrived at 104%]).

It's been a while since I did the battery reset with power manager. However, I believe that my deep cycle strategy is slightly more aggressive (the battery drains until the voltage drops to a point that the safety circuit engages).

Note to anyone that reads this: A true deep cycle should only be done if you believe your battery gauge to be faulty (i.e. your rated capacity is far below what you think it should be). This kind of deep cycle can induce serious wear and tear on Li-Ion batteries and is not recommended for regular use.

 

well what i do form 1st to 5th cycle is i charge it full then use it till it's like 5% left then recharge again till it hit 100%

so i if i charge my battery from 50%-100% then use it till it hit 50%
and i rechange my battery again from 50-100% will it count 1 cycle or 2 cycle ?

 

fyi... I had a problem with the original power manager on my t61p purchased March of 2008 that ignored my charge thresholds and fully charged to 100% all the time. I downloaded the latest power manager a month ago and now the charging works as it should.

 

In my opinion Lenovo batteries haven't faired well compared to others. I have a T61 that sits on the dock at night to charge and is on the road all day. My extended battery and 3-cell battery in the cd-drive give me about 8 hours of life during the day, but after about 8 months, there is a significant degredation in life. It takes our IT department about 1 month to get me new batteries, and by the time I do eventually get them, I have less than 3~4 hours of life.

 

You have a defective batter if a reset doenst help. Next time keep the settings at 4o to 50 not using high 90's as the upper band.

 

Actually that may not be necessarily true:
http://www.batteryuniversity.com/parttwo-34.htm

Look at the fully charged/40% scenarios chart (first visual):
At 40C just a bit over yours, a battery will have only 65% remaining life after 1 year if its charge is kept close to 100%

What I would suggest if you are in fact tethered that much to your dock:
Set the charging threshold to charge below 39%. Stop charging at 40%. Preferably pull the battery out of the laptop when it reaches 40% and set it aside. The 39%/40% values will make your laptop agressively try to maintain an installed battery charge capacity at 40%. At 40%, you don't really have to worry about having to stuff it in the fridge and room temp should fine. Though if you're anal, an air tight container with some of those silica gel packets in a fridge will extend life even more. If you end up with a battery at 100% while docked, or close to it, definitely put it in the fridge.

Then the beauty: Lenovo sells an external battery charger that essentially chargers all of their batteries (supposedly including the bay batteries). They are cheap, too. You can readily get a new one for about $25-30 and it's powered by a typical Lenovo AC adapter. When you know you need to be portable for a while, stick the 40% charged battery on the external charger say the night before.

This is another reason why I like the bay battery on Lenovos (and when Dell used to have it). Do the same charging strategy with the bay battery, but use those in tandem. This way when you undock to pull out your main battery, you don't have to hibernate. Also if your old battery is bad, DON'T toss it. Use it as your "scratch" battery because having a battery in the laptop, even if it can store only a few minutes of juice still makes it more convenient than restoring from hibernation.

I've had batteries last for years doing this, yet my batteries in my work computer (which I could care little about because they will give a new one if I ask) often last only a year 1.5 years..