Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Baxterdown

macrumors newbie
Original poster
Jul 8, 2007
25
0
Ft. Lauderdale, FL
We all know the deal with battery life and the number of charges. I'm worried about all this plugging the phone in the car to listen to iPod music then unplugging only to plug back at the office to sync with Outlook, to then unplug and plug back in the car, etc, etc.

How are all these little bursts of charging everytime I connect the phone to a USB port affecting my battery? Am I going through those famous 400 charges like a madman?

With my old phone I was used to charge the phone only when the battery was drained. I still do this with the iPhone; nonetheless, I would venture to say that everytime I plug the iPhone to a USB port for five minutes (where it charges by default) I'm somehow affecting battery life and performance... :confused:

Your thoughts would be greatly appreciated!
 

motulist

macrumors 601
Dec 2, 2003
4,235
611
Do NOT let your battery run down all the time if you don't need to. The best way to preserve modern batteries is to keep it connected to a power supply as often as possible. And only if it is really connected to power 24/7 should you specifically let it run down to zero every few months or so. (iirc)
 

kennyboy3

macrumors newbie
Aug 21, 2007
15
0
According to what I have read, each one of those little charges does not count as a complete cycle. A complete cycle is 100% of the power that the battery can hold.

So if you drain your battery 10% and then plug it up and recharge it, you have only used up 1/10 of a cycle. You would have to do that 10 times in order to have completed one cycle.

Supposedly, this is the type of charging that this kind of battery prefers and what works best.

So charge away!

The thing about the 300-400 complete cycles anyway is that even AFTER that, you should still have about 80% battery capacity, it won't be completely useless, so even after you do reach that point in a couple of years (or however long it takes) your battery will still be functioning, just not holding quite as much charge.
 

ero87

macrumors 65816
Jan 17, 2006
1,196
1
New York City
Do NOT let your battery run down all the time if you don't need to. The best way to preserve modern batteries is to keep it connected to a power supply as often as possible. And only if it is really connected to power 24/7 should you specifically let it run down to zero every few months or so. (iirc)

really, i heard the opposite! i thought that "calibrating" your battery is really effective, and that means once in a while running down the battery to zero.
 

motulist

macrumors 601
Dec 2, 2003
4,235
611
really, i heard the opposite! i thought that "calibrating" your battery is really effective, and that means once in a while running down the battery to zero.

Which is exactly what I said.

motuist said:
Only if it is really connected to power 24/7 should you specifically let it run down to zero every few months or so. (iirc)
 

thisonechance

macrumors regular
Feb 22, 2007
135
0
Chicago, IL
Alright, here is the deal.

Lithium-ion batteries, the most widely used battery that can be recharged, will NOT retain memory. What this means is that you do not need to cycle them (running dead then to full charge). To cycle a lithium-ion cell will harm its performance. As previously stated, if you run your battery down 25% and then charge, you have only used 1/4 of one cycle. So in theory, you can do that 1200 times before you hit the "300 cycle charge limit" that everyone is worried about. Do not worry, charge it every night and have no worries.

NiCd batteries do retain memory and therefore need to be cycled to retain good performance, but these are rarely, if ever, used in consumer electronics devices. They are usually reserved for remote controlled cars/planes and so forth because of the lower power-to-weight ratio.
 

motulist

macrumors 601
Dec 2, 2003
4,235
611
But once every few months it's good to run the battery down to zero to recalibrate the battery life reporting feature. But that's also catch-22 advice, because the only reason for the remaining battery info to be important is if you are sometimes running it down to zero and need to be careful, but if you're sometimes running it down to zero then you're already recalibrating your battery. :)
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.