🚀 go-pugleaf

The empirical evidence that leaving a battery in a laptop running off AC 
is overwhelming.  About 4 years ago there was a thread on this board 
that went on for almost a year and involved thousands of posts, and as 
someone who repairs laptops, I can tell you that we see this constantly. 
  Leave a battery in a laptop running on AC all the time, and you 
destroy the battery without ever having really used it in 6 to 24 months.

The reasons, however, are not as clear.

The two factors most often cited are overcharging and heat.  While, in 
theory, a laptop should stop charging a battery once it's fully charged, 
in practice many of them don't ... they apply a constant "trickle" 
charge, that is harmful to the battery.

The other factor is heat; simply put, a battery left in a laptop that is 
on AC all the time, and that is possibly running 8 to 24 hours per day, 
is exposed to heat.  Not necessarily internal heat from overcharging 
(that can happen also) or even heat associated in any way with the 
battery or it's charger, but simply heat from the CPU, the hard drive, 
the memory and all of the other "stuff" that is inside a modern laptop. 
  Anyone who has put a laptop on your lap knows that modern laptops get 
hot.  And a battery in a modern laptop gets hot.  And heat destroys 
lithium ion batteries (hence the suggestion to refrigerate them, but 
while theoretically valid, that may be practical overkill).

Both of these ... the design of the charging circuit and the thermal 
design and layout of the laptop itself ... are model specific, so 
exceptions may exist (probably do, in fact).  But as a general rule ... 
leaving a battery in a laptop being run all or essentially all of the 
time from AC power is a good way to destroy it.


Linea Recta wrote:
> "Meat Plow" <meat@petitmorte.net> schreef in bericht 
> news:31tufd.krm.19.1@news.alt.net...
>> On Thu, 13 Aug 2009 08:34:41 -0600, "Buffalo"
>> <Eric@nada.com.invalid>wrote:
>>
>> <snip>
>>
>> Doesn't apply to my experience, YMMV. Refrigeration may increase the
>> shelf life but the bottom line is still charge cycles.
> 
> 
> Taking out battery = less charge cycles.
> 
> 
>