06-24-2009, 07:08 PM

Is it safe for me to keep my new MBP connected to the power adapter most of the time? My MacBook basically stays home at my desk, so it just makes sense for it to stay connected.

06-24-2009, 07:15 PM

In a word, yes. The battery will stop charging once it's at full power.

06-24-2009, 07:26 PM

This may also be of help for you:

Best way to conserve long-term battery life?

06-24-2009, 08:43 PM

Also... Calibrating a MacBook Pro Battery

06-26-2009, 12:54 PM

Many thanks for the links.

I've got a couple of general queries regarding battery care:

1. Is it essential to calibrate the battery if the notebook is plugged in at all times? (Which naturally infers that the battery is always fully charged.) If so, why is this the case? Is the general rule of thumb 'once a month'?

2. When my second-hand MBP arrived last week, I realised that the battery was in very good condition with only 3 cycles. I then used the notebook without plugging it in until the battery was nearly depleted. So I plugged it in the next day and noticed that it actually charged right up to 100%. And it has been plugged in ever since. But why has the battery % dropped to 96 and not remained at 100%? It has been plugged in for days and the charge is still at 96%.
I've just a bit puzzled over this and wonder whether it was the manner in which I was using up the battery the first time prior to not having it plugged in (e.g. bluetooth on, wireless on, screen fairly bright). Which leads to my next Q:

3. I understand that battery life depends on what the user is actually doing. But for someone who uses up a fully-charged battery very quickly, does this make the battery more susceptible towards not being able to reach its 'full charge capacity'? In other words, the quicker the battery is depleted, the lesser it's able to reach 100% when its recharged.

I'd really appreciate it if anyone could shed some light on these Qs.

Cheers,
Joel

06-26-2009, 01:23 PM

Mine stays plugged in 98% of the time. I do put it through the calibration exercise once a month.

It will not recharge until it hits below either 94 or 96% (I forget which).

Sorry, but I'd recommend using your notebook the way you want to, quit obsessing about the battery, and just implement (or not) the suggestions for maintenance into your usage patterns. No need to understand everything on that technical a level to implement them and doubt we have an engineer hanging around that could fully answer them anyway.

06-26-2009, 01:31 PM

Originally Posted by bobtomay

Sorry, but I'd recommend using your notebook the way you want to, quit obsessing about the battery, and just implement (or not) the suggestions for maintenance into your usage patterns. No need to understand everything on that technical a level to implement them and doubt we have an engineer hanging around that could fully answer them anyway.

Exactly.

In my experience, batteries that are left fully charged on a machine that is mostly plugged in, tend to last a very long time. Those that are depleted often tend to need replacement sooner.

06-26-2009, 01:58 PM

I can testify to that.... My 2003 Toshiba notebook rarely if ever gets used on battery, but we keep it plugged in and fully charged at all times. I can still obtain 1 to 2 hours on battery using the power saver functions of XP. And that's for a machine which is pushing 6 years old.

Regards.

06-26-2009, 02:29 PM

Opposite with me.

I have had many windows laptops [through both business and pleasure]. All the laptops that were used only on battery power [as in charged up, then used off mains] kept a great battery life/range.

I had the same make laptop but I used it plugged in all the time [very rarely off mains] after a year or so it would last only 20-30 mins on battery power if I was lucky.

So... I will be using my MacBook off the mains most of the time.