Macbook battery calibration question

Portent of variable temperature, mostly. Not something to worry about.

Cheers - Jaimie

In article <yueh_uk-772582.09005714022009@surfnet-nl.ipv4.ptr.145.109.196.x.invali d

yueh_uk@yahoo.co.uk wrote:

I thought that, after a deep discharge recalibration, the value for "full charge capacity" in System Profiler, returned as "maximum battery  charge" and "current battery capacity" in CoconutBattery, remained fixed  until the next recalibration. After my last recalibration, the value is  jumping about daily, albeit over a fairly small range (~100mAh). Is this  a Portent of Doom?

Deep discharge isn't used with today's battery technology. In fact, competely discharging batteries of current types will ruin them. To answer your question we need to know what kind of battery you're using. We can work that out from what model (precisely) of computer you're using. Or youcould just go to this page

<http://www.apple.com/batteries/>

and not do anything it doesn't mention.

Speaking of which, my MBP battery is about a year old, maybe less (not sure but think got recalled) and is currently producing terrible results. Here's the information:
<http://eruvia.org/imagedump/coconutbattery-mbp.png>

That maximum looks way too low for something that age, doesn't it? Am not sure what period I'm getting from it at the moment but feels like an hour or maybe slightly less - I'll deliberately run it all the way flat today whilst timing things to see what I get.

Cheers,
Ian

That looks much too low, and I'd bet that Apple would replace it given its young age.

But what does the "Battery-loadcycles" value mean - the number of deep discharges/recharges? It looks like you use it only on battery for significant periods on 245 days, which might be one of the causes of the reduced capacity.

I follow <http://support.apple.com/kb/HT1490> (if that isn't deep discharge then I don't know what is :) ).
Perhaps I should have put Macbook3,1 in the subject line.

Thank you to Jaimie BTW for his suggestion that temperature variation comes into this- however I still don't grasp why the value in the battery's memory, once arrived at by a "calibration", is changing.

Or in the body - I think Simon missed the Macbook in the subject entirely, since they all use the same family of battery.

Thank you to Jaimie BTW for his suggestion that temperature variation comes into this- however I still don't grasp why the value in the battery's memory, once arrived at by a "calibration", is changing.

Nor do I, now you attract my attention to it. It's not something I'd worry about myself, but I'm easy going like that.

Cheers - Jaimie

Previously, Jaimie Vandenbergh wrote:

Deep discharge is a technical term for lead-acid batteries, I think. This is just a normal use - there's still considerable charge left in the battery, otherwise (as Simon says) the battery would be knackered after.

Jaimie, you are an optimist while I am a pessimist.
I cannot view the calibration process as normal use. AIUI even the Apple approved calibration process damages the battery slightly. It is the price that has to be paid to update the capacity info on which any time remaining estimate depends. Any user content to forgo that feature and who wished to maximise battery lifespan would be well advised never to calibrate their battery!

Sod that - if the battery isn't calibrated, the machine might run out of juice and go crunch, losing your data in progress and maybe mashing the filesystem slightly. The balance between discharge/recharging the battery (which is what it's there for, after all) vs data damage is *very* heavily weighted towards letting the battery take the pain, in my opinion.

This is something I'm familiar with, since (until I recalibrated) my Air had taken to doing just that. Very annoying it is too.

Cheers - Jaimie

For comparison, my MBP is 15 months old and coconut is showing 87% maximum and 127 battery loadcycles (whatever they are)

T.

I read a page on the Apple kb somewhere that said "full charge cycle equivalent", so presumably it's the same amount of watts in/out as you would have got through with 127 full charge/discharges. Or maybe the same amount of lifespan reduction as that.

Cheers - Jaimie

My iBook G4 battery: about 28 months, 128 cycles, 87%.

Daniele

My MBP battery - one year old, 312 load cycles and currently down to about 50% capacity. Iâve got through two batteries in 28 months here. --
The reply-to email is a spam trap but will be read

Wow. What's your work pattern that you can run through a whole charge pretty much every day?

Cheers - Jaimie

He's obviously a gigolo. No other explanation for such behaviour.

Daniele

I was thinking more "two hour train commute with old rolling stock that doesn't have passenger powerpoints", but your idea is far more interesting!

Cheers - Jaimie

Hang on - trains have power sockets nowadays? When did that happen, and is it widespread?

No, he really did mean PowerPoints. Some arse gets up and does a lengthy presentation complete with clip art, pixellated photographs and badly-designed graphs. Then all the other passengers have to clap.

Daniele

I think all Virgin ones have them, at least.

Hmm, I am the opposite of the above -- laptop two months old, 11 cycles.

b.

Northern Express - at least the long distance ones - too.

Hmm, I am the opposite of the above -- laptop two months old, 11 cycles.

Two years, 124 cycles.

Cheers - Jaimie

Heh :-)

I do tend to get untethered once per day.

The SW Trains from Hampton to Waterloo don't have them.

3-4 years (!) and 26 cycles. But the battery was swapped in one of the replacement programs a couple of years ago.

Chris Ridd wrote:

The SW Trains from Hampton to Waterloo don't have them.

Hah! Puddlehopping. Hardly time to get the machine open.

It takes 40-50 mins. Agreed that's not long enough if you're using a Windows laptop, but this 'ere Powerbook opens in a second or so.

It is fascinating seeing all the open WiFi networks as you whizz (OK, crawl) through the city.

50 minute train journeys are the perfect length, I find. Just enough time to sit back and watch an episode of 24 (or the like) on your iPod Touch ;)

T.

It would have to be something that didn't result in falling asleep and missing the stop.

Nod, I caught up on House on my iPod Touch on the way home on Wednesday. Just the job.

My MBP battery is two years old I think (I can't remember if i replaced this one),
28 months, 422 cycles and 73%

On 2009-02-20 12:33:10 +0000, Trooper said:

50 minute train journeys are the perfect length, I find. Just enough time to sit back and watch an episode of 24 (or the like) on your iPod Touch ;)

Unless, of course, you listen to podcasts that an an hour long. In which case they're damned annoying...

Paddington->Maidenhead on non-cattle truck: Approx 20 minutes. Not enough time to listen to a half-hour podcast Paddington->Maidenhead on cattle-truck: Approx 50 minutes, just under. Not enough time to listen to an hour-long podcast.

And yes, it does irritate me thank you - how did you notice...?

Cheers,
Ian