General Question

Trustinglife's avatar

How much energy does it use when I charge my iphone overnight?

Asked by Trustinglife (6618points) April 26th, 2008 from iPhone

Is it really much more energy efficient to plug it in only when needed? I normally charge mine overnight every night.

Observing members: 0 Composing members: 0

18 Answers

joeysefika's avatar

How often do you let the battery run completely flat? It is actually very good for the device if you let the battery run completely flat at least once a week. It prolongs the battery life. What battery do you have when you go to bed?

peedub's avatar

Wow, I do that out of laziness. I love it when I can justify laziness with valid reasoning.

Allie's avatar

joey: Is that true for all phones or just iPhones?

joeysefika's avatar

no i just know its true for laptops, and they both use lithium batteries so i would assume all phones; although i could be wrong

ebenezer's avatar

I don’t think that is quite right.

joeysefika's avatar

you may well be right @ebenezer when i got a laptop i was told explicitly by a techy i was talking to that it is important to drain a battery every so often to prolong battery life. But an phone may be different

Riser's avatar

according to Apple’s official stance, the iPhone battery does not develop the dreaded “memory” that traditional laptops do. As an iPhone user, I’m calling bullshit on this one.

joeysefika's avatar

thanks for clearing that up Riser. as i said i wasn’t 100% on that one

Riser's avatar

@Joey: I wasn’t calling your statement bullshit. I was calling Apple’s bullshit. just so you don’t think I’m attacking you.

joeysefika's avatar

oh sorry i misread thanks

Trustinglife's avatar

So does anyone have an answer to my question around energy efficiency?

iCeskate's avatar

@trustinglife, apparently not

reed's avatar

The best way to tell how much energy is used to charge your iPhone, or any device for that matter is to get a product like Kill A Watt. It plugs into the wall and then you plug your device into it and it measures the power draw. I bought one and measured every electrical product in my house. I was most shocked about how much power my halogen floor lamp consumed, almost 300 watts,which was more than my desktop computer!

uno's avatar

joeysefica: I’m afraid you are wrong.

Unlike nickel and lead-based batteries, a new lithium-ion pack does not need cycling through charging and discharging. Priming will make little difference because the maximum capacity of lithium-ion is available right from the beginning. Neither does a full discharge improve the capacity of a faded pack. However, a full discharge/charge will reset the digital circuit of a ‘smart’ battery to improve the state-of-charge estimation. (Source)

This coincides with my knowledge of lithium-ion batteries, the battery type used in your iPhone and MacBook, among others. They have a finite number of charge cycles. One charge cycle means using all the battery’s power, and then recharging it to full capacity. Using half the power and then recharging it uses half a cycle, doing that four days in a row uses two cycles.

Recalibrating a lithium-ion battery once every couple of months—do a complete cycle in one go—is good for making the battery know how much power is left. Do this every couple of months or so for good measure. This is probably what your friend was aiming for, but failure to read up on the subject made him get it completely wrong..

Nickel or lead based batteries however, is another story. But stay away from those.

Trustinglife: Use your lithium-ion battery whenever you need it, plug the charger in whenever you can, and recalibrate every couple of months. That’s what’s best for your battery, and what’ll make your battery last the longest. Connecting the charger to a fully charged battery won’t damage it at all, but rather make for fewer cycles used.

Trustinglife's avatar

Uno, great answer. How do I recalibrate a lithium-ion battery?

joeysefika's avatar

Ah well uno you learn something new everyday

uno's avatar

@Trustinglife: As the third paragraph in my previous post states, you do a complete cycle (total drain followed by full recharge) in one go. :-)

@joeysefika: That’s part of what makes them worthwhile ;-)

Answer this question




to answer.

This question is in the General Section. Responses must be helpful and on-topic.

Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
Knowledge Networking @ Fluther