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Re: Dead battery after storage on T400s

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Computer Nerd Kev <not@telling.you.invalid> wrote:
> bp@www.zefox.net wrote:
>> Computer Nerd Kev <not@telling.you.invalid> wrote:
>>> A difference in run time like that makes no sense to me unless
>>> you were working it hard or had power-hungry devices plugged into
>>> it during the first test. I guess Windows could also have been
>>> doing an upgrade in the background before, if you didn't disable
>>> that during the test (or, since it's Windows, if it ignored you and
>>> did something anyway).
>> 
>> After I got the new battery and started exercising it per the seller's
>> directions (which did seem to improve the performance) I gradually
>> learned about low power settings. When the new battery clocked in at
>> only 4.5 hours at low power settings, I got curious and re-tested the
>> old battery with the new settings. Lo and behold, they were similar.
>> The new battery is better, but for ~100$ not by much. 
> 
> You are actually timing how long until it automatically shuts down
> due to running out of charge, not just going from the estimated
> time remaining, right? Those estimations aren't reliable with old
> batteries.
> 
I tried to keep track of time to self-power-off. The machine was
idle, in the sense that I wasn't actively using it except to check
when I should take another look. WiFi was on, screen blanking was
automatic on a short (few minutes) interval. 


>> I'm left wondering:
>> 1. could a fifteen your old battery still have 80% capacity?
> 
> Discharge/recharge cycles are quoted as the key factor for battery
> aging, so it might fit if the battery was never used much.
> 
I have no information on how much the machine was used. It's
in very nice condition but that's more likely due to a fatidious
owner than lack of use. Most batteries are said to have a calendar
life along with a cycle life, so I figured calendar would be the
limiting factor. Maybe not. 

>> 2. should a new 4400 mAh battery last more than 4.5 hours?
> 
> Was the screen on/off for both the old "little over one hour" test
> and the new tests? I don't know what's normal for a T400s, but
> details like that and whether you were using it or just letting it
> sit would be important for getting a real answer.

The "little over an hour" tests were done when I didn't know about
the power control settings. Those obviously mattered hugely.

The screen blanking was left as it was for the initial tests. I think
5 minutes after keyboard/mouse activity, maybe 10. So, how often I
checked made some difference but I tried to be consistent.

At one point I found a review claiming 2 hours and change playing
a DVD but could find no dvd-playing program in the default Win10
system. Would playing a DVD be a more reproducible test?

In practice, what I have is what I got 8-) It works well enough
for my purposes, but it would be nice to find a reliable test
of the battery condition. To my surprise the T400S Hardware
Maintenance Manual seems mute on run times. I was hoping there's
some piece of software that writes battery output energy to disk
under some consistent loading benchmark. Guess not.  

Thanks for writing,

bob prohaska

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Dead battery after storage on T400s bp@www.zefox.net - 2025-01-14 01:50 +0000
  Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-01-14 18:11 +0000
    Re: Dead battery after storage on T400s not@telling.you.invalid (Computer Nerd Kev) - 2025-01-15 06:40 +1000
      Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-01-15 17:25 +0000
        Re: Dead battery after storage on T400s Adrian Caspersz <email@here.invalid> - 2025-01-15 21:02 +0000
          Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-01-15 22:03 +0000
        Re: Dead battery after storage on T400s not@telling.you.invalid (Computer Nerd Kev) - 2025-01-16 07:44 +1000
          Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-01-15 22:45 +0000
            Re: Dead battery after storage on T400s Computer Nerd Kev <not@telling.you.invalid> - 2025-01-16 13:47 +1000
              Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-01-16 16:10 +0000
                Re: Dead battery after storage on T400s Computer Nerd Kev <not@telling.you.invalid> - 2025-01-17 12:53 +1000
                Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-01-17 04:26 +0000
                Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-02-07 19:05 +0000
                Re: Dead battery after storage on T400s not@telling.you.invalid (Computer Nerd Kev) - 2025-02-08 07:49 +1000
                Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-02-08 20:33 +0000
                Re: Dead battery after storage on T400s not@telling.you.invalid (Computer Nerd Kev) - 2025-02-09 09:54 +1000
                Re: Dead battery after storage on T400s bp@www.zefox.net - 2025-02-09 01:44 +0000

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