USB Charging

[UnrealTechno]

I've seen posts about this, but none with actual answers. How about some thoughts on charging through usb? I picked up a USB to nokia adapter on ebay, but it seems slow (at best) to charge the phone and I've never left it plugged in long enough to get a full charge because I wasn't sure if the over charging circuitry is in the phone, battery, or charger. I also read somewhere that since the USB ports on my MBP are only 500mah, that it will never be able to fully charge the battery.

Is it safe to use this? Will it ever be able to fully charge my phone? Any guidance is appreciated.

edit: other people here have desktops that, if usb charging is safe, i could use. is there a way to find out how many mah the USB ports on windows machine provide?

[BanziBarn]

My opinion is that you'll never get a full battery, and if you try charging from a very low batter level you may even get the "not charging" message.

This is my experiance anyway.

[HoundDog]

Originally Posted by UnrealTechno

other people here have desktops that, if usb charging is safe, i could use. is there a way to find out how many mah the USB ports on windows machine provide?

I guess using the Nokia CA-100 USB charger should be safe, after all it's made by Nokia. Windows desktops do put out 500mah on each USB port, but it'll need to be an active hub, passive (without it's own power supply) ones only put out 100mah.

[3Shirts]

Originally Posted by HoundDog

Windows desktops do put out 500mah on each USB port

Hate to be a pedant but surely the OS installed doesn't affect the power output? I'm sure a linux desktop would output just the same

[Logan1981]

I've got my Nokia CA-100 USB charging cable plugged into a USB extension lead which in turn is plugged straight into the USB on the back of my PC (motherboard built in slot).

Can't say I notice any difference in the charging times between it and the plug charger that came with it.

[HoundDog]

Originally Posted by 3Shirts

Hate to be a pedant but surely the OS installed doesn't affect the power output? I'm sure a linux desktop would output just the same

Yeah you're right, should be the same on all systems, it's down to the offical USB specification.

I just mentioned Windows because that's what UnrealTechno was asking about.

[UnrealTechno]

Originally Posted by Logan1981

I've got my Nokia CA-100 USB charging cable plugged into a USB extension lead which in turn is plugged straight into the USB on the back of my PC (motherboard built in slot).

Can't say I notice any difference in the charging times between it and the plug charger that came with it.

Interesting because I've never seen a full charge from USB, but I'm hesitant to leave the phone plugged in for very long. It's not an official Nokia charger, but the Nokia one doesn't have indication that it's more than a change of shape.

I bring the OS into the discussion because I know how to check the power output on a mac, but not a PC. The real difference is the fact that the Windows machine is desktop, but I suppose that since USB is a standard that it will only put out 500 mah anyway.

Hmm, so does anyone think it'll harm the phone or battery to use the adapter?

[HoundDog]

To be honest, if you were using the Nokia USB charger, I would say it should be fine, but I tend to shy away from certain non Nokia accessories, power supplys and batteries included. So really wouldn't like to say if your one is safe or not.

[tonymy01]

I get the "not charging" unless the battery is nearly full (i.e. pointless!). I have tried this with 2 different laptops and a desktop (using a cheap chinese cable mind you, dunno how/why the Nokia cable would be different unless it had some kind of active components in it, maybe a capacitor to buffer a sudden current hit by the phone?)
I really don't think there will be any damage, the mains plug Nokia power supply doesn't get "feedback" from the phone to alter it's characteristics, it simply can provide a bit more current at 5V than the USB charger cable.

[UnrealTechno]

Originally Posted by tonymy01

I get the "not charging" unless the battery is nearly full (i.e. pointless!). I have tried this with 2 different laptops and a desktop (using a cheap chinese cable mind you, dunno how/why the Nokia cable would be different unless it had some kind of active components in it, maybe a capacitor to buffer a sudden current hit by the phone?)
I really don't think there will be any damage, the mains plug Nokia power supply doesn't get "feedback" from the phone to alter it's characteristics, it simply can provide a bit more current at 5V than the USB charger cable.

just what i was thinking, i'll save it for when i'm in a real pinch...i'm also a stickler for using nokia branded accessories

[pa49]

All the intelligence is in the phone! You can use any 5v source as a means of charging as long as the cable fits.
BUT, the Nokia wall charger gives 800Mah and this is needed to charge the phone from or near flat. The problem is that the phone indicators are notoriously inaccurate and you never know what the real state of the battery is and this leads to the second problem if you want to use USB ports to charge the phone.
The USB spec is 500Mah nominal. That means that when tested one at a time the port will be seen to give that figure. But, it's not enough to charge from or near flat as Lithium polymer batteries need that extra oomph to get them started.
Some manufacturers of PCs and laptops realise the problem and as the USB ports can become overloaded they up the spec (this can also be done as has been stated by powered hubs). There's no real way of telling what output USB you have but with a little management you can get round this.
No damage will be done by constant charge of Lithium polymer batteries in fact they like it and their performance should increase with use (to a point!). So my advice is charge it at every opportunity, keep it topped up and your USB port will do the job!
I have seen battery full through USB on my phone, but this has been when fully charged from wall charger and then changed to USB straightaway.
Some 3rd party USB chargers do give 800Mah (Bekin is one). I've had both their car and wall USB charger for some time and they perform really well. I also have a dual charge and sync cable which I use as well as a powerpal single AA battery charger and a 4X AAA battery holder which is brilliant when all other power sources are unavailable. You can use 800 Mah rechargeables which will go from flat!

[fiddles]

Originally Posted by pa49

No damage will be done by constant charge of Lithium polymer batteries in fact they like it and their performance should increase with use (to a point!).

I have always been lead to believe (and i may be wrong ) that any rechargable battery will benefit if from time to time you let it completly discharge. I have always let my phone totally discharge at least once a fortnight

[tonymy01]

Originally Posted by fiddles

I have always been lead to believe (and i may be wrong ) that any rechargable battery will benefit if from time to time you let it completly discharge. I have always let my phone totally discharge at least once a fortnight

Wrong technology. NiCd- definitely yes. NiMH- probably yes. LiIon (or Lithium Polymer)- definitely no.
Regards

[BanziBarn]

Originally Posted by pa49

Some 3rd party USB chargers do give 800Mah (Bekin is one). I've had both their car and wall USB charger for some time and they perform really well. I also have a dual charge and sync cable which I use as well as a powerpal single AA battery charger and a 4X AAA battery holder which is brilliant when all other power sources are unavailable. You can use 800 Mah rechargeables which will go from flat!

How does the brand of the USB charger make a difference? There's nothing really to them

[HoundDog]

Originally Posted by fiddles

I have always been lead to believe (and i may be wrong ) that any rechargable battery will benefit if from time to time you let it completly discharge. I have always let my phone totally discharge at least once a fortnight

I thought this as well, but I've just read the article on Li-Ion batteries on Wikipedia and now agree with tonymy and pa49. I'm gonna plug the phone in a much as poss now and see if it improves the how long the battery lasts.

Originally Posted by tonymy01

Wrong technology. NiCd- definitely yes. NiMH- probably yes. LiIon (or Lithium Polymer)- definitely no.
Regards

Originally Posted by pa49

No damage will be done by constant charge of Lithium polymer batteries in fact they like it and their performance should increase with use (to a point!). So my advice is charge it at every opportunity, keep it topped up and your USB port will do the job!

Here's the article