New T42 - understanding the battery

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alison · #1 Post by **alison** » Thu Dec 15, 2005 12:33 am

I just got my T42 - 2739 RFU. I love it so far although I am getting use to the keyboard after having a thai keyboard as my previous thinkpad experience. My question is the battery. It's great - 3+ hours on the web with full power. Are there batteries dos and don'ts to extend their life and get the most out of them (other than use power saving modes)? Is it bad to use it mostly off the battery? Do I need to plug it in every night?
Sorry such a newbie laptop question.
Alison

christopher_wolf · #2 Post by **christopher_wolf** » Thu Dec 15, 2005 1:05 am

Well, Congratulations on your new Thinkpad.

As far as LiIon batteries are concerned; the only things to avoid are temperature extremes and deep cycles (i.e. total discharges and recharges)

Here is a good link for that:

http://batteryuniversity.com/

That should give you a good deal of information on the Battery. It doesn't seem that plugging in the LiIon for a long time on AC or being Mobile for a long time harms it much, if at all. You might also want to get NHC to check the Battery Wear levels.

I imagine what you are thinking of is the "Memory Effect" associated with Nickel-Cadmium batteries in certain devices; this doesn't apply to LiIon Batteries.

alison · #3 Post by **alison** » Thu Dec 15, 2005 2:01 am

Thank you very much. I love that it does so well on batteries and want to keep that going.

brooklynboy · #4 Post by **brooklynboy** » Thu Dec 15, 2005 12:19 pm

christopher_wolf wrote:Well, Congratulations on your new Thinkpad.

As far as LiIon batteries are concerned; the only things to avoid are temperature extremes and deep cycles (i.e. total discharges and recharges)...

Are you sure about that last part? According to the "Battery Tips" provided through the ThinkPad Battery Maximizer Gauge*, you should

"3. Recondition your battery by letting your battery run to less than 3% at least once a month. Reconditioning the battery can restore some of your battery capacity."

-------------------------
*Click the Gauge, and then {Battery Information | Status Tab | Battery Health | Battery Tips} to display IBM's "Tips for Maximizing Your Battery Life," including the one above.

treker · #5 Post by **treker** » Thu Dec 15, 2005 12:31 pm

I have only found that deep discharge instruction in IBM battery maximizer. EVERY OTHER site about Litium Ion batteries I have found, clearly state to AVOID deep discharging as previous poster stated.

I don't do deep discharge on any of the many lithium ion batteries I own, including my T42. I think IBM instructions will give less than optimal battery life.

dr_st · #6 Post by **dr_st** » Thu Dec 15, 2005 12:43 pm

Which percentage would you suggest NOT to go down below?

#7 Post by **carbon_unit** » Thu Dec 15, 2005 12:49 pm

brooklynboy wrote:
christopher_wolf wrote:Well, Congratulations on your new Thinkpad.

As far as LiIon batteries are concerned; the only things to avoid are temperature extremes and deep cycles (i.e. total discharges and recharges)...
Are you sure about that last part? According to the "Battery Tips" provided through the ThinkPad Battery Maximizer Gauge*, you should

"3. Recondition your battery by letting your battery run to less than 3% at least once a month. Reconditioning the battery can restore some of your battery capacity."

-------------------------
*Click the Gauge, and then {Battery Information | Status Tab | Battery Health | Battery Tips} to display IBM's "Tips for Maximizing Your Battery Life," including the one above.

That may be true after your battery is down to about half capacity where there is nothing much to lose, but on batteries with most of their capacity intact it seems to have a detrimental effect on battery life.
At least that is my experience. YMMV

brooklynboy · #8 Post by **brooklynboy** » Thu Dec 15, 2005 1:44 pm

IBM's recommendations for lithium batteries and those by BatteryUniversity.com are easily reconciled. From batteryuniversity.com (emphasis added):

Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.

Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.

IBM recommends fully discharging the battery at least monthly.

christopher_wolf · #9 Post by **christopher_wolf** » Thu Dec 15, 2005 2:36 pm

The deliberate discharge is simply a device recalibration; doesn't help the LiIon battery chemistry any as the "memory effect" is non-existent. That is for the Battery gauge, I have also done a full deep discharge unintentionally, and that adds abour 3%-5% wear to the battery.

brooklynboy · #10 Post by **brooklynboy** » Thu Dec 15, 2005 3:44 pm

I'm agnostic about this, having just been following IBM's suggestion for lack of other input.

Just to clarify, are you saying that after 20 to 33 deep discharges the battery will no longer hold a charge?

christopher_wolf · #11 Post by **christopher_wolf** » Thu Dec 15, 2005 3:58 pm

Nope; not at all.

I am just saying that deep discharging, as I have noticed, can wear down the LiIon Battery; the Power Manger should handle the automatic recalibration of the System/Battery Inteface. I find that the default settings are already pretty good for battery maintenance.

brooklynboy · #12 Post by **brooklynboy** » Thu Dec 15, 2005 10:16 pm

Just wondering about the 3-5% (and hence 20-33 full discharges), but it makes no matter.

In a related issue, BatteryUniversity suggests removing the battery from a PC that is used exclusively on AC power, and storing the battery, 40% charged, in a cool place. The only caution given is some manufacturers' warning that the PC may be subject to intrusion by dust or moisture.

Question: Does having a battery installed act in any way as a surge suppressor? Would it be inadvisable to operate a ThinkPad battery-less for this reason?

#13 Post by **GomJabbar** » Thu Dec 15, 2005 10:30 pm

I don't believe the battery acts as a surge surpressor, but it does act somewhat like a UPS. It prevents you from losing data and possibly damaging some files from an unexpected power outage. This could be caused even by someone tripping over the AC adapter cord.

If you have the ThinkPad plugged into an UPS, then having the battery removed should be no problem - provided you 'know' the cord will not be tripped over or accidentally unplugged.

davidspalding · #14 Post by **davidspalding** » Fri Dec 16, 2005 1:03 am

Nothing is a good surge supressor like a good surge supressor ... though a good basic UPS will give your TP/dock cleaner power than right out of the wall. Considering the cost of a 750 VAC UPS and the total cost of a TP, the UPS is a small investment for peace of mind. Just IMHO....

dr_st · #15 Post by **dr_st** » Sat Dec 17, 2005 9:04 am

Buying a UPS for a notebook? Yeah, right. And carrying it around with me all the time?

NeoteriX · #16 Post by **NeoteriX** » Sat Dec 17, 2005 9:20 am

All the paranoia about battery life is horseradish. Just use the battery naturally--it's performance will degrade over time, but you can't help that, it's part of the natural life cycle, so why bother?

The A/C adaptor acts as a natural surge protector, and if you're feeling especially paranoid, Belkin and APS sell nifty little laptop surge surpressors that attach to your battery. The main concern for surge damage would typically be through phone lines.

#17 Post by **carbon_unit** » Sat Dec 17, 2005 1:36 pm

NeoteriX wrote:All the paranoia about battery life is horseradish. Just use the battery naturally--it's performance will degrade over time, but you can't help that, it's part of the natural life cycle, so why bother?

The A/C adaptor acts as a natural surge protector, and if you're feeling especially paranoid, Belkin and APS sell nifty little laptop surge surpressors that attach to your battery. The main concern for surge damage would typically be through phone lines.

I have arrived at the same conclusion.

davidspalding · #18 Post by **davidspalding** » Sat Dec 17, 2005 3:31 pm

dr_st wrote:Buying a UPS for a notebook? Yeah, right. And carrying it around with me all the time?

IMNQSHO (... Not Quite So Humble...) You're making presumptions about my suggstion, smarty pants. Unless you have a wheelbarrow, toting a UPS is ludicrous. But then, I'm talking about a laptop, so when I carry it, I use something called battery power.

As for plugged in at home...

davidspalding wrote:though a good basic UPS will give your TP/dock cleaner power than right out of the wall

... plugged into the Dock II, I use a UPS. Unless you've had experience with docking stations during blackouts, you might not understand the appeal. If you have a UPS for monitor, modem, router, external drives, there's no harm having the docking station on backup power as well.

Clean power. It's not just a myth. I have brownouts and spikes where I am on a more than monthly basis. Blame the South, blame thunderstorms, blame sunspots, blame Canada, whatever, having clean power for expensive computing components is generally reassuring, and occasionally a lifesaver.

chikin03 · #19 Post by **chikin03** » Mon Dec 19, 2005 11:06 am

Thanks for the insight into battery conditioning, guys. I was worried about discharging the battery only a little then plugging it back in. Good to know that's not an issue.

Two power-related questions:

1) Will my adapter work in the UK (with a plug shape adapter)? The adapter says 100-240V, 50-60Hz but I wasn't sure.

2) Will my laptop function safely plugged into the car through a 75-watt power inverter from Radio Shack? There's been some worry about vulnerability to surges.

leegaard · #20 Post by **leegaard** » Mon Dec 19, 2005 6:51 pm

I would certainly buy the original IBM dual power PSU (or I might say .. Have already done that

)

#21 Post by **bill bolton** » Mon Dec 19, 2005 8:21 pm

> 1) Will my adapter work in the UK (with a plug shape adapter)? The
> adapter says 100-240V, 50-60Hz but I wasn't sure.

Yes, it will work fine.

Be aware that there are some GPOs (General Purpose Outlets) in the UK which will not deliver power if there is no ground pin inserted into the socket, so make sure that your plug shape adapter has a ground pin on the UK plug side... some cheap ones don't.

> 2) Will my laptop function safely plugged into the car through a 75-watt
> power inverter from Radio Shack? There's been some worry about
> vulnerability to surges.

There are laptop power supplies (from IBM and others, including Targus etc) that will work off a ~12V vehicle "cigarette lighter" socket. I strongly recommend that you go down that path rather than use an DC to AC inverter to provide 120V AC to feed into your normal laptop mains supply.

Your laptop mains power adapter basically switched mode type (SMPS). Feeding the the input of a DC to AC inverter that does not have adequate filtering on the ouput waveform to make it suitable for use with SMPS could lead to "interesting" outcomes!

Cheers,

Bill

#22 Post by **Kyocera** » Mon Dec 19, 2005 9:26 pm

The A/C adaptor acts as a natural surge protector

I would not put money on this, a surge/spike will travel right through the AC adapter. I have not read anywhere that it serves that purpose. Poorly wired buildings, surges, spikes, is an unfortunate side effect of AC power, DC is much easier to control. Best case scenario is to use a UPS, but not practical, a surge strip of high quality (like ESP).

Power Anomalies and Surges (article from AARP)
Power anomalies and surges also pose a big threat to computer equipment. The good old electricity that has become so necessary is actually filled with variances and fluctuations. While these fluctuations do not affect standard appliances such as lamps and toasters, they can affect sensitive, intricate equipment like computers. There are many reasons for power anomalies and surges; the electric utility companies are not solely to blame. Old interior wiring is often a culprit. Even in buildings where the wiring is perfect, many everyday appliances like microwaves, vacuum cleaners, and hair dryers can cause data-damaging interference. These power problems may not seem serious, yet a recent study by IBM showed that the average computer was susceptible to two or more power anomalies each and every day.

Laptop power supplies are tiny and need all the protection you can get.

davidspalding · #23 Post by **davidspalding** » Mon Dec 19, 2005 10:46 pm

If my old avionics training still holds, AC adapters convert AC (with variances, noise, spikes, etc.) into DC via transformers. I would hope that a good AC adapter would NOT transmit a voltage spike right up to the DC plug on the laptop. In that sense, "dirty power" ought not to be too big a problem.

No, wait. Some kinds of spikes or lightning strikes are CURRENT, not voltage, right? That could right up through the unit into the laptop power port. So yeah, the idea of an AC adapter being a natural surge supressor doesn't apply to all cases. Better safe than sorry, particularly here in the south where lightning storms are all too common.

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