"Winston_Smith" <
inv...@butterfly.net> wrote in message
news:espogbh87ihoq7i12...@4ax.com...
> On Mon, 11 Apr 2016 18:36:03 -0700, Gunner Asch wrote:
>
>> Ive used the old girl for the past 15 yrs with
>>absolutely no issues, other than the battery pack died about 14 yrs
>>ago..but I generally simply plug it into the wall anyways when using
>>it.
>>
>>Ive been offered either a Dell E6400 XFR or a
>>General Dynamics/ Itronics VR-2, 2.0GHZ Toughbook
>
> No exerience with either but some with Dell. I have the Vostro 1000
> which is a pure bottom end machine. It's done what I need and has
> been
> remarkably reliable with just one bitch.
>
> The factory battery lost it's ability to take a charge at about 3
> years. Plugging it in didn't due it, the machine just bitched it
> wanted a new battery and refused to boot.
>
> I bought a brand X off the internet and it gave me a reasonable
> number
> of years service.
>
> The point it the brand X has gotten so it can't take a charge either
> but it's happy on line power.
>
> I have to conclude there is some circuitry in the Dell battery
> (obviously for charge control, etc) but something extra that
> monitors
> the battery and tells the computer to be stubborn to sell a battery.
> The brand X probably has nothing beyond basic battery function needs
> and doesn't snitch to the operating system.
Lithium batteries need circuitry to protect them from overcharge,
too-deep discharge and excessive charge or discharge current. The
circuits to do that track State of Charge (SoC) by monitoring current
and voltage and can report them to the laptop.
http://www.ti.com.cn/cn/lit/ds/symlink/bq2058.pdf
That handles the real-time control while a slower-responding PIC etc
would determine and remember SoC and inform the parent device.
As the battery ages and degrades the SoC value becomes inaccurate
unless the battery is fully discharged and recharged to recalibrate
theSoC estimate to the measured actual capacity. Eventually the
supervisory circuit can completely lose track of the battery's
deteriorating condition and transmit nonsense.
This shows you what the battery reports:
http://www.hwinfo.com/
I have some old batteries that need to be reinserted a few times to
nudge their voltage up enough with the initial qualification test for
the charging circuit to accept them.
Dell laptop chargers contain a Dallas memory chip that tells the BIOS
the charger's power rating when the laptop boots, via the center pin
of the power connector. If the comm link fails the laptop may assume
it's on the lowest capacity charger, run at half clock speed and not
charge its batteries. The higher power charger gets quite toasty
charging a nearly depleted battery even with the laptop Off.
--jsw