I think there's an offset how the two OS revisions reports temperature. So far, I only hear of people upgrading to SL reports higher CPU temperatures. Yours seem to be the opposite. Also I remember closing the LCD lid would cause a higher temperature than leaving it open.

Sorry to ask such question, but is it better to continue charging our laptops(battery full) instead of draining the battery and charging it back full or vice versa? Which is better for our battery life

With magsafe u normally cant see your batery indicator is full. it will be around 97-99%. Draining the battery and then charging i back will add cycles to your battery.

Adding cycles to my battery? Is that good?

Nope. Try to keep the charger plugged in as often as possible. Reduces the number of cycles.

hmm, in a simple way maybe we can think like this, mbp charges is 7k thats mean 7k is the battery life span. the more charges = the older your battery.

a rechargeable battery got a certain number of cycles before it starts to perform badly.

i.e. if you have a new battery with just 1 cycle, maybe it can last for 5 hours. but after a while, maybe around 300 cycles (300 times the battery went from full charge to empty charge), maybe the battery can last for 2 hours like that.

not accurate, but juz an example so what you'd want is to reduce the number of cycles possible. but try to go thru at least 1 cycle every 2 weeks. this is called calibrating, to make sure ur battery wont 'forgot' its own power

Wow. Thanks for all the advises!

read this > http://www.apple.com/batteries/

Like the rest who have said it, a typical discharge & charge cycle can be accounted from the point it is fully charged at 100% and depleted at 0% (theoretical) and recharged at 100%. Thats what we call a typical full cycle. However, it is not always as clear cut. Consider this scenario where you have a fully charged battery at 100%. You use 20% of it (remaining 80%) and then decided to charge it to full again back to 100%. That is also considered as one cycle. So you kinda waste a potential of 80% of charge for that particular cycle. It is important to note that this is not the same as 'memory effect' of older battery technologies. 'Memory effect' prevents the full effective use of the potential charge in a battery.

Some battery manufacturers have mechanisms in place to make sure a battery cell is used in a 'balanced' way. Sony uses a battery care program to limit battery cells to only charge to 80% or lower. That is to prevent it from hitting 100% in case you didn't fully deplete the charges for that cycle. Now I do not know why not hitting 100% is important but I remember back in university days where a very good indicator of a fully charged Li-ion battery is when its temperature suddenly shoots exponentially. Most charging circuitry has these fail-safe mechanism to detect voltage and temperature of the cells. Maybe that has something to do with it.

So for regular and typical usage, if you have started using the battery keep using it until it is fully depleted. And when you charge it, keep charging it until full. And continue to keep it plugged in for as long as possible especially if you don't move from one place or another. If you're mobile, do your best to find a power point. If you have to use the battery, then remember to use it until it is fully depleted. Rinse repeat and you're good to go.

By the way, it is perfectly alright to keep the battery plugged all the time. It will not harm it because battery charge circuitry is smart enough to isolate the battery and power your laptop directly from main power. However, HEAT will reduce the longevity of a battery.

This post has been edited by davidmak: Oct 25 2009, 02:27 AM

Quite a good explanation. But i must say that "Sometimes"(strongly emphasize) from 80% usage and charge till 100% doesnt count as a cycle. And same goes to 30% which i tried before. Guess what for my 2months mbp is only having 9 cycles? I bring my laptop everyday to school and use it w/o magsafe. Damn happy and very satisfy about the my battery life cycles and mh.

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Added on October 25, 2009, 4:14 amhttp://eshop.macsales.com/shop/Modbook found a modded mac website. saw 2 tablet there. the price is really painful.

This post has been edited by ginolo: Oct 25 2009, 04:14 AM


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Hey, Im planing to get a MBP(15" 2.53GHZ 9400m) but I don't know should I really need this MBP spec.
Im still a student, normally is web surfing, photo editing, sometime play l4d.
What's your opinion guys?

Sorry for the late reply. I was sick the past few days.
It was easy. I used a credit card.
I got myself the student discount. Just send them proof of full time study for them to verify.
Installing is a breeze as well, download, install and enter your serial number. Just make sure you keep your ID in a safe place either physically or online with no clue of it's purpose. Coz this is what you need to report your stolen mac.
Occasionally check orbicule's website to see if there are updates for your undercover. They are good at keeping their software in tip top condition, releasing v3.2 for snow leopard, though the previous one still works.

I really think there is no reason not to get this for every mac. If you mac doesn't have this installed and it gets stolen, you virtually have no hope whatsoever of getting it back. But with this installed, at least, you still have some hope of retrieving it, and unleash your fury on the thief (if he didn't sell it).

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Added on October 25, 2009, 1:38 pmSorry but I beg to differ in some aspects. A lithium-ion(cobalt)/lithium-polymer battery (used in laptops) doesn't "remember" how many charge cycles it has gone through. It is simply a figure the electronics count to keep track of the battery.

Li-ion's do not have any 'memory effect' (as you mentioned) unlike Ni-MH batteries (Nickel metal hydride) which do; and isn't actually old tech compared to Li-ion-cobalt; Just different types of battery chemistries for different purposes. NiMH's prefer to have a full charge and discharge cycle, but Li-ion's aren't too happy with that. Not doing a full discharge DOES NOT "waste" that charge cycle.

Having a full charge and discharge once in a while is fine (also recalibrates the electronics monitoring the battery) but avoid doing it on purpose ALL the time (unless that's really your usage cycle then by all means use what you invested for).

A battery charging circuitry doesn't use the temperature of the battery as a charging indicator, but rather as a shutdown and disconnect mechanism, coz if you overcharge or overdischarge a lithium-ion-cobalt, you may get what you call a "thermal-runaway" potentially with flames! Instead it uses voltage as an indicator, and it varies between different battery chemistries.

To quote a fellow flashaholic... (flashlight hobbyists in other words. we live on the edge of loose li-ion cells on our devices so we know the pros/cons and dangers of these little things)
he has summed it up pretty well:
Correct me if I'm wrong though.

This post has been edited by MetalZone: Oct 25 2009, 01:55 PM

if u want 15", that's already the best choice. 9400M can handle l4d no problem, but maybe not the highest spec.

if u can bear with 13", more choices for you . the new macbook seems like a good offer to me. plus, if u go for a 13", u can buy a lot of accessories with the price difference.

hmm. Is there big difference of screen size between 15 and 13?

Oh ya, I fail to mention that the counting of charge cycles is really tricky business. For one, there's no proper standard to address these 'metrics' so one manufacturer accounts cycles differently from the other. Some move into more conventional methods as long as 100% potential charge has been discharged while others are more aggressive. The truth is a battery usually outlives the manufacturer's claims provided they are well maintained and always used. Remember heat? Heat is a very bad component for Li-Ion. Cause heat changes their structure.

Yes, Li-Ion does not have memory effect. I remember myself specifically mentioning that its not memory effect. As mentioned before, there are areas that aren't clearly defined in how cycles are accounted for. You're right, Li-Ion likes to be charged and discharged many times. Which is why it is perfect for today's electronics and usage lifestyles. Sometimes I wonder why Sony implements charging programs like they did for their VAIOs. There must be a reason.

And of course temperature is not the only parameter charging circuitry look for. They do have dB cutoffs, voltages, and negative dB inputs. What I was saying is that fundamentally, when a Li-Ion cell approaches a fully charged state, its temperature would shoot exponentially. That is the critical nature of Li-Ion, one that is dangerous and bad for its longevity. Sorry if I wasn't clear enough. Writing in the middle of the night does seem to be blurry hehehe...

This post has been edited by davidmak: Oct 25 2009, 04:26 PM

Whao... So many winding replies today one? Sunday too free ar?

can i use windows on mac? how?

No worries, it's just a constructive discussion.
Yeah I know that u did mention that that it's not memory effect (check my post). Just wanted to clarify things further.
However, just wanna clarify something u mentioned above: "Li-Ion likes to be charged and discharged many times."
Instead, Li-ion likes to be charged but doesn't like full charge and discharge cycles (ie 100%>0%>100%>and so on).

I've not read about of the charging algorithm sony used as u mentioned, charging to 80% of the full capacity. But I can help you explain why they probably did so. Let's give an example. A lithium-ion-cobalt's typical maximum cutoff voltage is 3.2V. Let's say battery A is always recharged up to 3.2V. And battery B is always recharged up to 3.0V only. Battery B will have a longer lifespan than battery A. Because as mentioned in my previous post, i quoted that maximum charge is actually detrimental to the lifespan of the battery. The downside is that, you have less battery capacity to utilise.

Thus, to tie back to the charging parameter you mentioned, manufacturers don't make the charging circuitry to charge to the point the "temperature shoots up" as it would be severely detrimental to the lifespan of the battery; but instead cuts off charging of at a lower voltage, say at a maximum of 3.2V for lithium-ion-cobalt for example.

rx330
Sunday too free? haha. Just feel like engaging in a little bit of technical discussion.
But I think we're going off topic

But anyway, that should give u a better understanding on the perks of your notebook battery.

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Added on October 25, 2009, 6:46 pmYes.
2 ways:
1. Bootcamp (native windows boot using the full resources of the computer)
2. Virtual machine (running piggyback on top of Mac OS). Programs that can do this: VirtualBox (free), Parallels Desktop, VMWare Fusion.

This post has been edited by MetalZone: Oct 25 2009, 06:47 PM

Yup, Sony has very different thinking approach with their batteries (since their battery fiasco ). Its called the Battery Care program. Its meant to prevent short cycles like using 10-20% of 100% and then charge it back to full. Its a combination of hardware and software implementation. With Battery Care, the default limit of 80% is set so that it can never be charged to full thereby preventing short cycles. It can even go on more aggressive levels like 50% or any percent the user set. The downside is that you reduce the capacity potential of your battery in exchange for better longevity and service life. Besides, it also implements very different charging strategies.

Its something I don't entirely understand but I do know at the point where a battery reaches 100% charge, the temperature would go up very high. Maybe that is not healthy like you said.