[Euphrates]

I was wondering, since batteries in Video cameras and such supposedly have to be charged the whole way and then totally used before recharging to prevent damaging the battery, is it OK like Apple says to let it charge a little even if the Pod is only 1/4 used? It just doesn't seem right to plug it in, update, then take it out when the little charging symbol is still going...

[scaught]

and how do you know when the thing is done charging?

You're thinking of nickel cadmium batteries which need to be fully charged and discharged for optimal use. The iPod uses a different type of battery.

[rjenkinson]

Originally posted by scaught:
<STRONG>and how do you know when the thing is done charging?</STRONG>

it displays the word "charged" and a full battery icon.

-r.

[Jerommeke]

Originally posted by rjenkinson:
<STRONG>

it displays the word "charged" and a full battery icon.

-r.</STRONG>

it only does that when not charged by a computer

see the topic i posted earlieron on same topic

[as2]

You can tell when it is fully charged as the bars on the battery indicator do not move and stay solid.

I do have another issue with charging though. I was charging my iPod via my iMac when my iMac entered sleep mode. My iPod contunued to charge, but there was a high pitched whine eminating from the inside of the iMac. It might have been from the motherboard, or the firewire card, but I could not tell.

Has anyone else experienced this?

Regards

Adam

[Petter]

I did post this over at apples forum earlier so I can post it here as well. =)


With Lithium-Ion and Lithium-Ion polymer cells there is no need to discharge or run them down to emty before charging them - thats one of the nice features with li-Ion cells!
All rechargable cells have a life span which nowadays is directly related to the amount of energy passed thru the cell, not the amount of cycles specificly.
This means that '2 half cycles' [100% charged cell -&gt; 50% discharge -&gt; recharge to 100% -&gt; 50% discharge -&gt; recharge to 100% again] is equal to one full cycle [100% charged cell -&gt; 100% discharge -&gt; recharge to 100% again] when it comes to life span.
(hope you understood that...)

If the ipod goes into a recharge cycle yet again after allready beeing charged is not really that bad - as long as the critical values like temperature, voltage etc is not reached. All Li-ion type cells need special circuits to monitor the cells while charging and discharging!
The charging process need to be stopped, and this is taken care of by the circuit, when the voltage reach 4.2-4.3 V (depending of manufacturer) the circuit will then again start the chargingprocess if the voltage goes under 4.0 V (depending of manufacturer as well)
Overdischarging is as bad as overcharging! The cell will get damaged if the voltage drops below 2.5-2.3 V (depending of type and manufacturer) and the protective circuits are there to stop that from happening.

If you run down your li-ion cell to emty (about 2.9V) it will take longer to fully charge it due to the fact that it need to be initially charged very carefully (with about 1/7 of the ordinary current) this is not bad but it will increase the time it takes to fully recharge the cell again.

[Euphrates]

Thank you all, and yes I think I understood that, Petter. I just wanted to make sure it wasn't the same as those other batteries.

[Petter]

Originally posted by Euphrates:
<STRONG>Thank you all, and yes I think I understood that, Petter. I just wanted to make sure it wasn't the same as those other batteries.</STRONG>

Cool.

I feel I have to add something to my statement regarding 2 x half cycles equals one full cycle - Most of the times you can count 2 half cycles as the same as one full cycle... but it's not really the whole truth...

You can get a dramatic increase in cycle life by _not_ discharging the cell completely before recharge! With only a 10% reduction of the discharge profile you will most likely double the life (as in cycle life) of the the cell! =)
So charge it as often as you can - you will most likely get more cycle life out of it! (I dont think the Sony cells Apple is using is so much different from all other manufacturers)

[ 01-01-2002: Message edited by: Petter ]