Laptop batteries

[Larry Grover]

MrKnisely wrote:
> Christoph Bier wrote:
> 
>> Phil Cooper schrieb am 06.01.2006 22:26:
>>
>>  
>>
>>> Hi;
>>>
>>> This is probably more of a hardware question than an Ubuntu one, but  
>>> you guys seem to know your stuff! I have a HP laptop running Ubuntu,  
>>> and it never goes any where - it's my main "desktop" machine and it  
>>> stays plugged in at least 80%+ of the time. My question is, would it  
>>> be better for the battery if I removed it altogether, or does it  
>>> being sat in the laptop with power not adversely affect it?
>>>   
>>
>>
>> Heat decreases lifetime of the battery. That's why I always remove
>> the battery of my laptop when it's on AC (it's very easy with my
>> laptop).
>>
>> Best,
>>   Christoph
>>  
>>
> I agree with Christoph.
> 
> Mike K.
> 


While it's true that excessive heat has a negative effect on battery 
life, the specific location of the battery in any given laptop may not 
expose it to much heat, depending on how the laptop is constructed.  For 
example, in my laptop the battery is in the coolest part of the laptop, 
far from the "hot spots" -- it doesn't get much hotter in the laptop 
than it would if it was removed and simply exposed to ambient temperature.

Older laptop batteries (NiMH) were subject to a pronounced "memory" 
effect.  If these batteries received partial, shallow discharge/recharge 
cycles over and over again, they would lose capacity.  Newer laptop 
batteries (Li-ion) suffer much less from this effect.

Removing the battery while the laptop is on AC might extend the life of 
the battery somewhat (how much?), but I can think of two good reasons 
*not* to remove the battery while on AC:

(1) Unless you run your laptop on a UPS, if you have a power 
interruption your laptop will shut off immediately.  This is never a 
good thing.  Even with journaling filesystems, you are likely to lose 
some information.

(2) Laziness.  Really, I'd rather not bother removing the battery (and 
have to remember to replace it if I wanted to unplug the laptop and 
carry is somewhere).

Regards,
Larry