[X4U] Battery Capacity Question

[Stroller]

On 12 Jun 2006, at 06:31, Lee Licata wrote:
> ...
> The 5400 mAh battery's current capacity is 5097 with a cycle count  
> of 112.

I presume you're measuring cycle count manually - the number of times  
it has been fully charged & discharged?
But how are you measuring the capacity, please? I presume the 5097 is  
in mA and you're using a multi-meter?
I'm afraid my GCSE physics classes were long enough ago that I can't  
recall if current should be measured in series or parallel.

> So, is there consensus as to how long I should expect this battery  
> to last, at what point should it be replaced?

Apple's laptops have been using Lithium-Ion (Li-on) batteries for at  
least 2 years (maybe 3 or 4); this type is said to be much less  
susceptible to "charging memory" or loss of performance with ageing  
than older models of battery.

> As a non-scientific point of reference, when sitting on the couch  
> wirelessly retrieving my mail, surfing the web, etc, etc, I seem to  
> get just over 2.25 hours from the battery....

I get about the same with my 12" Powerbook, which is 22 months old,  
and am quite happy with that. When mine was new it used to claim a 4- 
hour charge in the menubar under the same circumstances, but I think  
it only really gave 3.5 hours.

Stroller.