Hi:

I have a new Macbook Pro and am keeping my old iBook G4. Just wondering if computers are like cars and have to be fired up every now and then to keep them running? I want to be able to use my iBook as a backup if my Macbook Pro needs to be serviced.

Thanks.

Rita

Hi, Rita,

I'll contribute the fact that you should run the battery down and recharge it at least once a month to keep it functioning properly, and I'll suggest that you calibrate the battery before you even get involved in the monthly regimen.

<Apple Portables: Calibrating your computer's battery for best performance>

macs with pram batteries will be running off them to keep up the clock if unplugged from power. not an issue with the ibook, but we've gotten in imacs frequently that are at people's "summer homes" that are powered off and unplugged during the winter and they go through pram batteries pretty fast.

Hi Artie: For some reason I never got my Fine Tuned Mac email like I usually do. So I didn't know you answered. Thanks for the idea.

I always let me battery run down once a month but only calibrate my new one. I may start calibrating the iBook as you suggest. If I lose my battery, no big deal. I will just plug it in and use it. I just didn't know about the other workings of my computer. If they needed to be run now and then like a car! LOL!

Rita

Hi: I never got my email alert like I usually do, so I didn't realize you had responded to my post.

I'm not sure exactly what you are saying. Do I let my battery run down or not?

Other than that, I just wondered if the computer would work in general if I left it alone for months or years at a time.

Thanks.

Rita

Hi, Rita,

Calibrating your iBook's battery is an easy job...no big deal to do every month; calibrating your MBP's battery is, on the other hand, a pain in the butt procedure, but it should still be done several times a year. (If there's an optimal number that replaces several, I don't know what it is.)

As for running your iBook periodically, I know that computers can be stored for extended periods of time, but I have no idea if there's a limit. (Actually, Apple suggests that stored computers have their batteries run down to 50% beforehand, but I suspect that working it once a month will be a better life-extension procedure.)

V1's post is of no consequence to you, because portable Macs don't have PRAM batteries.

Hi:

Okay, thanks, very helpful. I will look at the link for calibrating iBook batteries, then. Yes, calibrating Macbook Pro's is a pain. I've done it once already. I usually just let the battery run down in my iBook and then plug it in. I will see what your link says.

Thanks again.

Rita

Okay, I looked at your link. Here goes:

Portables with built-in batteries
Current Apple portable computer batteries are pre-calibrated and do not require the calibration procedure outlined in this article. These computers use batteries that should be replaced only by an Apple Authorized Service Provider.

Who knew? I calibrated it for nothing.

Portables with removable batteries
iBooks and PowerBook G4s other than the PowerBook G4 (15-inch Double-Layer SD) You have to fully charge and then discharge your battery only once to calibrate it. After that, you can connect and disconnect the power adapter when the battery is at any charge level.

Just once? I was doing it every month. At least that's what the replacement battery instructions said I had to do.

Rita

artie505,

You wrote:
It would be more accurate to state:
V1's post is of no consequence to you, because your iBook does not have a PRAM battery, which is also known as a backup battery.

All PowerBook G3 models have a PRAM / backup battery.

Some PowerBook G4 models have a PRAM / backup battery.

Dianne: How can I tell if I have a PRAM backup battery in my iBook G4?

Thanks.

Rita

According to Mactracker no iBook ever had a backup (PRAM) battery. Instead they drew power from the main battery to retain the PRAM contents.

Okay. Thanks so much.

Rita

That's true of any device which has a lithium ion battery; Li Ion batteries (including lithium ion polymer, or "LiPo" batteries) always last lionger if they're discharged to 40-50% charge before storage.

Because of a quirk in the way lithium ion chemistry works, a fully charged lithium battery that is not used will permanently lose a certain percentage of its capacity each month. Lithium batteries really want to have the electrons keep moving. This applies to, for example, cell phone batteries, remote controlled toy batteries, BlueTooth headset batteries, (some) lithium power tool batteries, and anything else that uses a lithium power cell. (Some lithium power tool batteries--the larger, heavier ones--use a different kind of chemistry, lithium manganese oxide, that doesn't have this problem.)

Lithium ion batteries are also extraordinarily sensitive to heat. The permanent loss in capacity goes up very, very quickly as temperature increases. leaving devices like cell phones or cameras with rechargeable batteries in a hot car is a great way to wreck the batteries, as I discovered with my digital SLR camera.

Ok, thanks. As stated above on the apple website, they say you only have to calibrate the battery once. Which is it?

Also I've read where you completely discharge it and then charge it back up. Today I read on the internet that draining it completely is known to ruin a battery! So much contradictory info. What'a gal to do?

I really like the one that said I only have to calibrate it once!!! LOL!!

I think I have a Lithium Polymer battery. Not sure how different that is from an ion battery.

Rita

There are several problems involved with information gleaned from the internet including:

1. There are a variety of batter types and within each type there are often multiple variations each with different requirements.
2. The specific battery type in your computer is often not easy to discover.
3. Much of the information available on the internet does not identify the battery type that it applies to apparently assuming all rechargable batteries are created equal. A bad assumption.
4. Much of the information available on the web is out of date and is undated making it difficult to even guess whether or not the recommendations are still valid.
5. Few users have either the time or the inclination to spen much, if any, time digging for the answers.

So what is a gal, or guy, to do?

1. First and foremost read the owners manual that comes with the computer. Hopefully that will provide the answer(s) you need straight from the horse's mouth — ie. Apple
2. Check HELP on the computer itself — although most of the information there is simply a copy of the contents of the printed Users Manual
3. Go to Apple Support and search the knowledge base but be sure you read the article(s) carefully to be sure you have found the one that specifically relates to your computer. If you are unsure what computer you have go to the Apple Menu > About this Mac > More info and verify the model there. By-the-way, you can get to the online support from there by clicking on "Support".
4. If all else fails look for answers on FineTunedMac

Draining a lithium battery completely destroys it instantly. That's not the same as draining it to the point where your computer says it is at 0% power and shuts down.

Lithium batteries contain tiny computers that monitor the battery and shut it off before it reaches complete discharge. So when your computer turns off, it isn't because you have completely drained the battery; it's because the battery has switched itself off with just enough charge left to avoid damaging it.

When Web sites talk about draining a lithium battery completely, they mean to 0% charge, which destroys it. When Apple talks about draining the battery completely, they mean down to the point where the battery switches itself off, which doesn't destroy it.

In no particular order, and in addition to joemikeb's and tacit's comments I can add the following:

For maintenance purposes, there is no difference between Lithium-ion and Lithium-polymer batteries. You treat them the same way. This includes initial calibration and occasional subsequent recalibration: so there is no such thing as 'once' with these batteries. The exceptions are built-in batteries: those don't require calibration (and, by inference*) recalibration.

Periodic recalibration of 'eligible' batteries is recommended to reset the battery's internal circuitry's tracking of remaining charge, which over time can deviate from the actual number. The comment that built-in batteries don't require calibration and recalibration suggests that this deviation is not (much of) an issue here.

Draining a Lithium-based battery during normal use or calibration does NOT ruin it, as long as you don't store it in that condition. Prolonged storage may cause a drained battery to lose the capability to hold any charge. On the opposite end of the charge scale, storing a battery at 100% charge may cause (only) partial loss of battery capacity, and hence battery life.
The critical question here is how long a drained battery can be kept before it starts to deteriorate. As calibration entails holding a drained battery in that state for several hours before recharging, it's safe to say it'll take longer before problems arise. But since it's not clear how much longer, I follow Apple's recommendation to charge such batteries ASAP.

If you do need to (re)calibrate, I find it helpful to run a WiFi utility that monitors WiFi access points in the vicinity. This literally sucks the juice out of your battery in a hurry, and makes sure the battery gets the required downtime after draining. But because of that downtime, I tend to run the recalibration overnight.

Some more useful links:

- Apple - About Notebook Batteries
- Getting The Most Out Of Your Mac’s Battery – Part I


*) To be clear, I haven't found a single Apple suggestion that built-in batteries need re-calibration, only that they don't need (presumably initial) calibration. Likewise, it doesn't say anywhere that (re)calibration is detrimental to the battery. My guess is that it cannot hurt and may help.

Thank you. I did what you said and went to the support section via the About This Mac. Funny, in About this Mac it states I have an LCD display, and the manual it led me to says I have an LED display! Ha-ha! That's what I get for researching the heck out of stuff.

Rita

Thanks for that explanation. I would have never known.

Rita

I have a built-in battery. Thanks for all the info.

Rita

As with the "calibrate by draining the battery/draining a lithium battery destroys it," both of these are correct.

You have an LCD display. It's a flat screen display that uses a matrix of liquid crystals to produce color images.

It's also an LED display; the backlight that makes the display glow is an LED backlight, rather than the older florescent backlights that used more power and produced less even illumination. Technically, the full name of the type of display in your Mac is "LED-backlit LCD display."

You are so smart and knowledgeable. Thank you.

Rita

Thanks for pointing out that some older portable Macs had PRAM batteries.

> To be clear, I haven't found a single Apple suggestion that built-in batteries need re-calibration, only that they don't need (presumably initial) calibration. Likewise, it doesn't say anywhere that (re)calibration is detrimental to the battery. My guess is that it cannot hurt and may help.

But taking Apple's statement that (re)calibration is unnecessary together with their failure to describe a procedure to be followed if you want to do it on a lark, what procedure would you suggest?

And finally, since this thread has meandered all over the place without bringing Rita's battery issue to a conclusion, will she be better off storing her iBook G4 in a closet with its battery having been run down to 45-50% or running the battery down to theoretical 0% and fully recharging it once a month despite never using it?

- I would use the basic procedure for the newer portables (MacBook/Pro), which is to:

1: charge to full capacity.
2: use battery in fully charged state for 2 hours (e.g., by running a WiFi access point monitor scan).
3: disconnect from power adapter and continue use until Mac shuts itself off.
4: let Mac sit in that condition for 5 hours (no more than 10 hours).
5: recharge again (uninterrupted!) to full capacity.

- She should follow Apple's (6 mos or longer) storage recommendation, and start with a 50% charge. After that, I'd check/recalibrate at least once annually*.


*) The 50% storage charge Apple recommends is for prolonged periods of storage (> 6 mos), but that duration depends on the condition of the battery at the start of storage. Therefore I would first check the charge level after 3 months and recharge to 50% if it's less than, say, 30%. The lower the residual charge, the less likely it is to last for a longer period of time.

If the remaining charge is still close to 50%, I'd check it again after another 6 months. If that turns out OK, I'd check the battery at least once a year, assuming the charge-loss allows for that. When storing a portable Mac for prolonged periods of time, it's good to remember that Apple recommends to 'complete a charge cycle at least once a month' for optimal performance and life. That means that storage, however well done, will detract from that optimum.

Thanks. I'll do that with the iBook. I've already recalibrated the Macbook Pro even though it looks like I don't have to because the battery is built in and has different rules according to the Apple site.

Thanks.

Rita

> I find it helpful to run a WiFi utility that monitors WiFi access points in the vicinity. This literally sucks the juice out of your battery in a hurry, ....

Keep forgetting to post... I use full-screen iTunes visualizer, the most processor intensive process I can think of, to run my battery down quickly, but it comes with the downside of generating a lot of heat, which I'd like to avoid if I can, so I'd appreciate your suggesting which utility may be my best alternative.

Thanks.

I just ran across these two docs:

OS X Lion: Calibrate the battery in a portable computer clarifies the calibration procedure for user-replaceable batteries, and How to Prolong Lithium-based Batteries - Battery University presents some useful statistics and suggestions.

WiFi is quite energy-intensive, and easily among the strongest battery-draining activities, particularly if one can maximize the scan-frequency. Although I really can't say which is the best in this category, I often use the freeware Airgrab WiFi Radar (version 1.4, regardless of other claims; 'registration' is useless) on a PPC iMac running Leopard, but any such utility would do. I don't know if WiFi monitoring generates less heat than your iTunes visualizer (doubtful with high energy consumption), but that's easy to find out.

As long as it's running cool now, I won't need it. But it's good info to have should it happen again with an app I don't want to get rid of. Thanks.

Rita

Thanks, but this experiment had a really inauspicious beginning...your link took me to v 1.2, not 1.4, and the app wouldn't even launch in OS X 10.6.8.


I'll check out other options.

AWR has some quirks, 'variable' versioning being one of them, but it works under Leopard (Airport must be ON). I have no idea about subsequent OS versions. There are alternatives for those, including freeware options, but I haven't tried them.

I've d/l'ed AirRadar. which does work on my deuced Mac(hina), and will report back.

If anybody is interested:

iTunes Visualizer runs my battery down 50% in 75 minutes.

The aforementioned AirRadar is a no-go, because I'm not about to purchase a $20 app for the sole purpose of running my battery down, but I found KisMAC (freeware), which runs my battery down 50% in 85 minutes.

Neither Visualizer nor KisMAC causes much additional fan noise, i.e. heat.

So, I guess the answer is if you want to sit back and relax and enjoy watching your battery run down you use Visualizer, but if you want to work you use KisMAC.

Thanks for the update! Of course, now I wonder how much faster a combination of visualizer and WiFi monitor would drain the battery...

Your turn to experiment.

I don't mind experimenting, but in order to achieve proper accuracy and comparability it seems to me that this would require you to ship me your deuced Mac(hina) for testing...

I thought of that ( ), but it's on hold until the guy whose MacUpdate post that suggested that he was able to configure a Mac that shipped with Mt. Lion to run Snow Leopard gets back to me no/yes --> details ([prayer][amen])....or I just may do it myself.

On the other hand, you could rerun the entire experiment on your Mac.

Edit: Together, we could both answer the question at hand and get an insight into battery evolution.

70 minutes with both running...seems odd that it wasn't less, but more interesting is that virtually no extra heat was generated.

Your turn

Edit: Nope...no response. Damn!