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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:
>>> bp@www.zefox.net wrote:
>>>> Computer Nerd Kev <not@telling.you.invalid> wrote:
>>> I've done that, replacing with cells from a battery from a broken
>>> laptop. The tricky thing is that the battery cases are all stuck
>>> together differently. Some are plastic welded, others
>>> snap-together, others glued (with glue of various strengths). The
>>> battery I dismantled for cells ended up a shredded mess of plastic
>>> due to strong glue, but the plastic welded case for the battery I
>>> was re-celling came apart without much damage.
>>> 
>>> If attempting that, you do want to remember that denting,
>>> puncturing, or shorting out a Li-Ion cell can all cause it to
>>> catch fire, sometimes after a delay or when charging.
>>> 
>>> If you do trust the Chinese reproduction batteries, note that
>>> they're often not much more expensive than buying enough new
>>> individual Li-Ion cells (except maybe for the most dodgy
>>> unbranded Li-Ion cells).
>> 
>> I wondered about re-celling the old battery pack, but couldn't
>> find any descriptions of folks actually doing it and one demo
>> of letting the magic smoke out, so I'm wary.
> 
> Seems like there are videos on YouTube, though I made it up as I
> went along since it's just a case of hooking things up like they
> were when you started (after fighting your way in). I've read some
> battery controllers might 'die' when you disconnect the old cells
> if you don't hook external power to them, so they're tricky.
> 
>> It's also unclear what kind of cells are required. 
> 
> The type of Li-Ion cell is almost always 18650. The capacity (mAh)
> is the only thing that varies, and can be calculated by comparing
> the battery circuit (add up the capacity of the batteries in
> parallel) with the capacity of the battery pack if it's not printed
> on the cells themselves (often it is). Note that over-stated
> capacity figures are a common complaint with cheap Chinese
> replacement cells. You can also choose to use different capacity
> cells, but the OS's battery hours estimate might be wrong then.
> 

I can't see how the cells could be 18650, the pack is only about
half an inch thick. Even AA cells are too thick to fit. Maybe that's
why replacement packs seem scarce.

> You will need cells with solder tags attached so you can wire them
> up. They are usually crammed together tight in the battery pack so
> it can be tricky.
> 
>> In the meantime I set the power button to shut down while on both
>> battery and mains. Turned the machine off, it seemed to do so.
>> Couple hours later I noticed the machine was warm, opened the lid,
>> found it was up and running. Re-checked "what the power buttons do"
>> and they still claimed to cause shut down. This looks like a bug.
>> Anybody else seen this behavior? 
> 
> Sometimes I've had thinkpads intermittently fail to fully turn off
> at shut-down, just sit running with a black screen and maybe the
> CPU fan running. Holding the power button down for a while forces
> them off. It doesn't boot back up though, just hangs, so it must be
> a bug.
> 
> You could check that Wake on LAN is disabled in the BIOS settings.
>
 
I looked for wake on LAN, but couldn't find it in the BIOS. Might it
be set in Windows 10? Haven't seen it there, but I'm mostly unfamiliar
with Win10 and could easily miss it. I'm certain I didn't hit the power
button, but did unplug and plug the power jack and also open/close the
lid. Could either trigger a startup?

The machine stayed off all night, when I checked the battery this morning
it read 12.26 volts, same as last night. No parasite drain. Knowing now
where to test voltage direct on the battery I'm tempted to apply a small
light bulb load, say 2 amps, to do a capacity check independent of the
computer. Any hint what the several intermediate contact on the battery do?

Thanks for writing!

bob prohaska
 
 

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Thread

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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