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USB Charging

24 replies · 7,604 views · Started 25 July 2007

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?

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.

UnrealTechno wrote: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.

HoundDog wrote: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 :tongue:

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.

3Shirts wrote: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 :tongue:

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.

Logan1981 wrote: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?

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.

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.

tonymy01 wrote: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

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!

pa49 wrote: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

fiddles wrote: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

pa49 wrote:
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 :con? :icon14:

fiddles wrote: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.

tonymy01 wrote:Wrong technology. NiCd- definitely yes. NiMH- probably yes. LiIon (or Lithium Polymer)- definitely no.
Regards

pa49 wrote:
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

What tonymy01 and myself have been saying is honest to goodness good practice!
I have many years experience in battery technology and in charger and electronic battery monitoring. The Li Poly batteries are to all intents and purposes self monitoring. They don't need conditioning or discharging or cycling in any way.
Keep them fully topped up whenever poss and you will get the best performance.😉
The only downside is that when there go they just go!

BanziBarn wrote:How does the brand of the USB charger make a difference? There's nothing really to them :con? :icon14:

It's not the brand itself it's just that some brands will push out 800Mah whilst some stick to the USB minimum spec of 500Mah.
Just because "there's nothing really to them" doesn't mean they don't do a complex job. It's all on such a small scale it looks simple but they have to be well designed and built to do their job properly. Fotunately most after market kit is of really good quality!

pa49 wrote:
Keep them fully topped up whenever poss and you will get the best performance.😉
The only downside is that when there go they just go!

doesnt this mean more changing cycles and hence shorter life ? i confused a bit
as i read cycles is limited...

mwice wrote:doesnt this mean more changing cycles and hence shorter life ? i confused a bit
as i read cycles is limited...

There is no such thing as a charge cycle for Li poly. They quote it to give some idea of how long they will last and it is usually conservative.
The have an optimum operating "range" of charge which for our purposes is of no interest whatsoever.
But, they do not like being discharged!!!!!!!!!!!
That's why they need the extra oomph to get them going.
Just keep 'em charged whenever you can!😉

Possibly the most complete answer I've ever gotten form a forum, you guys rock. On a side note, we just picked up a "free loader" solar charger/usb charger. Any of you use them? I was in a buying mood already

UnrealTechno wrote:Possibly the most complete answer I've ever gotten form a forum, you guys rock. On a side note, we just picked up a "free loader" solar charger/usb charger. Any of you use them? I was in a buying mood already

They are superb!

hi,

anyone ever tried this cheap usb charger:
cgi.ebay.com/USB-Charger-Cable-for-NOKIA-N95-E65-N93i-N70-6280-N73_W0QQitemZ320141716484QQihZ011QQcategoryZ35191QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

does it work? or like tonymy01 said that it works only if the phone is nearly charged?

thanks in advance 😊

aubreyk wrote:hi,

anyone ever tried this cheap usb charger:
cgi.ebay.com/USB-Charger-Cable-for-NOKIA-N95-E65-N93i-N70-6280-N73_W0QQitemZ320141716484QQihZ011QQcategoryZ35191QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

does it work? or like tonymy01 said that it works only if the phone is nearly charged?


That is exactly the one I got (I got a battery, desktop stand, car charger and that very same next to useless charger..well, almost the same, it has an adapter for the 1mm plug).
It also has a problem with if I bump it, the phone connection is not so good, and with "bestprofiles" setup to change profile when the phone is charging (to, say, put the lights on), I can see the phone toggling the profile lots of times when bumped.

(see attachment for mine).

Regards

Attachments: 27072007256s.jpg

I'm with one of the previous posters who said only buy Nokia battery related products (including chargers).

I've gone down the third party line many a time in my illustrous Nokia ownership years and its always produced problems.

Stick with Nokia, you can't go wrong. The official Nokia USB charger isn't exactly expensive. The only downside to it is the VERY short lead.

aubreyk wrote:hi,

anyone ever tried this cheap usb charger:
cgi.ebay.com/USB-Charger-Cable-for-NOKIA-N95-E65-N93i-N70-6280-N73_W0QQitemZ320141716484QQihZ011QQcategoryZ35191QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

does it work? or like tonymy01 said that it works only if the phone is nearly charged?

thanks in advance 😊

That's just like the one I got, it seems to work fine, but then again it made me want to start this thread because it's not official. Mine works fine, but I doubt I'll ever buy non-official stuff anymore.

what's this "bestprofiles" thing?

edit: wow, sweet app, i've been looking for something like this...if only it was free 😞 does anyone know of something similar but free?