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View Full Version : As soon as my N800 warranty is up...


thebeck
2007-01-31, 06:15
The first hardware mod my N800 is going to get is two little wires going from the USB port to the DC input port so my N800 will charge whenever it is plugged into USB and I don't have to take the charger everywhere. It would have cost Nokia nothing, err less than nothing to do this for me. Why even have a DC port? Anyone else give this a go yet?

Milhouse
2007-01-31, 06:33
Won't you also need some diodes on there as well to stop you from injecting 5v DC into the USB port on your computer? :)

But yeah, pretty lame for Nokia not to support USB charging in this day & age. :(

thebeck
2007-01-31, 06:47
Didn't think about that. I don't see what harm it would do but better be safe than sorry. maybe some epoxy in the DC port would take care of that problem. :)

convulted
2007-01-31, 10:01
I agree that not including this functionality is lame... however they may have included the DC port simply for the fact that some devices that are USB hosts aren't that great as charging devices (e.g., laptops). I'd rather have a small adapter that I can use whenever necessary that splits the USB cable into separate USB and power heads that can than plug into the 770/N800--but I guess that's just me :-) I like flexibility...

thebeck
2007-01-31, 10:25
You can plug a higher amperage ac/dc or dc/dc converter directly into the usb port if it is designed with a usb plug. I don't see a great need for a high amperage charger while connected to the pc but I suppose putting two usb ports on the N800 wouldn't hurt. Or they could sell a splitter for those who need the functionality.

TA-t3
2007-01-31, 12:01
As the N800 (unlike my Palm T3) supports a proper, normal charge plug instead of those ridiculous, unreliable error-prone multi-connectors, I would just go for a USB-to-chargeplug cable instead, charge from USB that way and leave the N800 USB connector alone. One of the _good_ things, nay, one of the _best_ things Nokia ever did was to stop using a proprietary junk multiconnector in their devices (unlike most other makers). Which also means, IMO, that the need for USB charging isn't that big really. Anyway, that's how I think about it.

jethro.itt
2007-01-31, 17:44
And there's also the fact that you cannot use the (external) memory card while connected via USB...

ioan
2007-01-31, 18:51
Why even have a DC port? Anyone else give this a go yet?

what about an Y cable? one end for the computer's usb port, one end to the n800's usb and one end with a jack for the power (my son's psp has a cable like that).
Here is a picture of the cable:

Milhouse
2007-01-31, 20:06
Or even this (http://www.engadgetmobile.com/2007/01/18/nokia-triumphantly-enters-21st-century-offers-usb-charging/). :)

thebeck
2007-02-01, 01:47
Or even this (http://www.engadgetmobile.com/2007/01/18/nokia-triumphantly-enters-21st-century-offers-usb-charging/). :)

Yeah, now that I think about it that would probably be better than taking the soldering iron to my n800.

gowen
2007-02-01, 07:35
By mains charger recently stopped working so I rigged up a cable from a USB plug to a 2mm power jack. Although, my 770 reported that it was charging, it never actually got to the point where it reported being fully charged. The mains charger is rated as 890mA, so I suspect that the 500mA maximum available from a USB port is not enough. I may try to see if two USB ports in parallel does the trick.

spycedtx
2007-02-01, 08:55
By mains charger recently stopped working so I rigged up a cable from a USB plug to a 2mm power jack. Although, my 770 reported that it was charging, it never actually got to the point where it reported being fully charged. The mains charger is rated as 890mA, so I suspect that the 500mA maximum available from a USB port is not enough. I may try to see if two USB ports in parallel does the trick.

I'm trying to remember basic EE here.

Aren't USB ports pumping out 5v? If so, then sticking 5.6ohms of resistance in the path should up the amperage to be equivalent of the mains charger.

TA-t3
2007-02-01, 09:38
spycedtx: You're not remembering enough of the basic EE ;-)
gowen: Lithium batteries can be charged with a low current, it should simply take longer. The problem could be that your USB port isn't as well regulated as it's supposed to be, i.e. the load of the 770 may result in the USB voltage dipping down and get too low. You will need to measure with a meter to figure out what happens. (Actually, sticking in that resistor will lower the current drain of the USB port and may thus help the port to keep 5V, but that doesn't help anyway because the voltage _behind_ the resistor (i.e. at the 770) will be lower).
Two ports in parallel might actually work though.

Grue237
2007-03-07, 02:56
So has anyone tried this yet? Or will I be the first?

rhackenb
2007-03-07, 21:15
If I am reading this discussion correctly, the USB port on the n800 can't be used to charge the n800. I have a USB charger that came with my i-Blue 737 GPS receiver. It outputs 5v at .5 amp. Too bad I can't use it.

What I am really looking for is something called a battery box that hold 4 AA batteries and is used as an emergency charger for a mobile or PDA. I found one at Paden.com that serves this purpose for units that charge through the USB port. The idea is that you insert 4 AA batteries and the device to be charged sucks juice out of the batteries and charges the internal battery. This would come in handy if you were off the grid on a canoe or hiking trip.

The link for it is

http://pdaden.com/shop/cart.php?target=product&action=view&product_id=16686&category_id=301

Has anyone heard of anything like this with a 2mm plug?

-- rhackenb

Karel Jansens
2007-03-07, 21:46
If I am reading this discussion correctly, the USB port on the n800 can't be used to charge the n800. I have a USB charger that came with my i-Blue 737 GPS receiver. It outputs 5v at .5 amp. Too bad I can't use it.

What I am really looking for is something called a battery box that hold 4 AA batteries and is used as an emergency charger for a mobile or PDA. I found one at Paden.com that serves this purpose for units that charge through the USB port. The idea is that you insert 4 AA batteries and the device to be charged sucks juice out of the batteries and charges the internal battery. This would come in handy if you were off the grid on a canoe or hiking trip.

The link for it is

http://pdaden.com/shop/cart.php?target=product&action=view&product_id=16686&category_id=301

Has anyone heard of anything like this with a 2mm plug?

-- rhackenb

I bought a 4 battery emergency charger for my Archos PMA430 (together with a lot of other stuff for my Archos) from here:
http://www.pjbox.co.uk/Archos%20Accessories.htm
It never worked properly with my 770 (charged only to about 80%), but charges my N800 effortlessly, if a little slower than from an AC outlet. The tip is the "old style" big Nokia tip, but I have a connector with the small, new Nokia tip. I get around two recharges (not from completely zero!) with decent (2.5A) rechargeable AA batteries, or I can keep it plugged in and more than double the N800's battery life (especially nice if I want to play some Internet radio and snooze off).

It's not cheap, but until now it remains the only emergency charger that will charge my N800; none of the cheap, gas station models (they usually take AAA batteries) works. I guess it's got something to do with the charging circuitry in the N800.

sapporobaby
2007-03-07, 22:24
Have you checked out: www.solio.com? I have one and it works great. Never without a charge for my iPod, phones, N800, etc....

rhackenb
2007-03-07, 22:58
Thanks for the input on the Archos battery box. I was wondering what these things do. Couldn't I simply take a 4 AA battery holder and connect a wire with 2mm plug on it and plug it into the N800? That seems too simple. Is there some kind of circuitry that is needed?

-- rhackenb

Karel Jansens
2007-03-08, 00:12
Thanks for the input on the Archos battery box. I was wondering what these things do. Couldn't I simply take a 4 AA battery holder and connect a wire with 2mm plug on it and plug it into the N800? That seems too simple. Is there some kind of circuitry that is needed?

Nokia makes a 3.5 to 2 mm adapter. Expansys has it:
http://www.expansys.com/p.aspx?i=125505
I found mine (a different one) with a collection of other tips and adapters in a generic charger package.

I honestly don't know if the Archos emergency charger has circuitry on board. All I know is that, with the right adapter, it charges pretty much anything I have that uses Nokia-ish chargers (my Sony Ericsson P910 phone, a bluetooth headset, an old Nokia phone I had lying around, my brother's Treo 650, my N800 and oh yeah: my Archos :cool: ). It's quite a useful piece of kit, especially on a twelve hour flight.

The Archos charger is also the only emergency charger that works with the N800; I have a couple of the cheap ones (5 euros) lying about and none of those will work with the N800.