Difference in battery life - wall vs computer - Page 2

sl0ppyshat · 12-09-2008, 01:21 AM

i will test this starting tomorrow morning. First with the wall charger then comp.

will post screen shots

but everyones phone behaves differently so my test will probably differ from everyone else

TJL7386 · 12-09-2008, 10:38 AM

Also am curious to how you get 24 to 48 hours out of your phone. What are your settings? 3g ... Location on/off ... etc ...

I usually get about 12 to 20 hrs before my phone is almost dead and needs a charge. I keep 3G on and location off. Bluetooth only when I am using my head set.

srjeffery · 12-09-2008, 11:07 AM

Originally Posted by TJL7386

Also am curious to how you get 24 to 48 hours out of your phone. What are your settings? 3g ... Location on/off ... etc ...

I usually get about 12 to 20 hrs before my phone is almost dead and needs a charge. I keep 3G on and location off. Bluetooth only when I am using my head set.

3G on all the time, but on wifi most of the day. location off, bluetooth off. 3-4 hrs usage between browsing, listening to music, talk. i have always let it run down before charging, and always fully recharge. battery life can be sporadic, and there are times when i'm getting less that 24 hrs.

JoeT · 12-09-2008, 11:26 AM

From a technical perspective, this is kind of like asking if a bucket of water lasts longer if you fill it from the hose rather than the sink.

A battery is little more than a bucket of electricity. You might fill it faster (hose/wall versus sink/computer), and you may empty it faster (3G versus Edge), but one has nothing to do with the other -- UNLESS it can be shown that non-wall charging isn't completely charging the battery -- but since the voltage is the same, that's extremely unlikely.

There's a usage counter in Settings that tracks the amount of usage since the last charge -- a handy tool in case someone wants to give this a real test -- but I don't think you'll find anything statistically interesting.

someguy · 12-15-2008, 10:11 PM

Originally Posted by JoeT

From a technical perspective, this is kind of like asking if a bucket of water lasts longer if you fill it from the hose rather than the sink.

Your wall charger is well regulated to push 5Volts at 1Amp. Your USB port will push 5Volts at as low as 100mA depending on your setup (ie. using a USB hub, current draw of other devices using the same bus, etc.)

It's more like your battery is a stretchy balloon, the sink and hose fill at the same rate, but the sink runs a higher water pressure than the hose. So where the hose would eventually stop filling the balloon when the balloon doesn't want to stretch any further, the sink would be able to stretch the balloon more since it can push in water at a higher pressure.

I would expect the battery to last longer when charged off the wall outlet. This depends on your situation however, if you have a USB port that will push 1A with no other peripherals drawing from it, then it will be the same as charging from the wall. It is doubtful that anyone has that situation.

Cheers.

Napoleon_PhoneApart · 12-16-2008, 12:19 AM

Originally Posted by sl0ppyshat

I have found that my batt. last longer charging via wall. and charges quicker also

My brother says the same thing.

FirstIphone · 12-16-2008, 11:29 AM

no numbers to back it up but mine seems to last longer with wall charging.

I left it in the wall last night and on my 1 our trip to the office today had it using blue tooth and running Trapster the whole way and the bat still showed full charge when I arrived. I will have to try it but I dont think a pc charge would have netted the same batt result.

BTW...Just to add data to the thread...
3g
blue tooth always on
wi fi always off
medium usage with browser and apps
no music usage
very little video usage (yet)
Normally charge from wall overnight while it is powered down
Battery is still 1/4 to 1/2 charged at end of day.

JoeT · 12-16-2008, 02:10 PM

Originally Posted by someguy

It's more like your battery is a stretchy balloon

Um, no. Batteries do not have variable capacities based on charge rate.

FirstIphone · 12-16-2008, 02:21 PM

In the world of RC Cars a slow charged battery will last longer than a fast charged.
So there may be something to the thought of charging slower resulting in a better charge, that in turn will last longer.

smknSRT8 · 12-16-2008, 02:23 PM

Originally Posted by srjeffery

i only charge mine once it's below 20%, and always fully charge it. it takes typically less than an hour to fully charge from the wall, and at least 2-3 hrs from my computer. i normally get 24-48 hrs of life, but notice at times getting less than 24 hrs with no noticeably different usage.

There is your problem. You should not let you battery drain down that low every time. Li-ion batteriies only have a certain number of cycles in them, and you are only increases that number. It is a good idea to charge the phone whenever you can, then about once every other week go ahead and let it drain then charge.