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gowen |
2007-02-01
, 07:35
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Posts: 223 |
Thanked: 67 times |
Joined on Jun 2006
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#11
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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.
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2007-02-01
, 08:55
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Posts: 114 |
Thanked: 7 times |
Joined on Jan 2006
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#12
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Originally Posted by gowen
I'm trying to remember basic EE here.
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.
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.
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2007-02-01
, 09:38
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Posts: 3,841 |
Thanked: 1,079 times |
Joined on Nov 2006
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#13
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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.
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.
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2007-03-07
, 02:56
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Posts: 35 |
Thanked: 1 time |
Joined on Mar 2007
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#14
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So has anyone tried this yet? Or will I be the first?
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2007-03-07
, 21:15
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Posts: 84 |
Thanked: 6 times |
Joined on Feb 2007
@ Noblesville, IN USA
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#15
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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?targ...ategory_id=301
Has anyone heard of anything like this with a 2mm plug?
-- rhackenb
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?targ...ategory_id=301
Has anyone heard of anything like this with a 2mm plug?
-- rhackenb
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2007-03-07
, 21:46
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Posts: 3,220 |
Thanked: 326 times |
Joined on Oct 2005
@ "Almost there!" (Monte Christo, Count of)
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#16
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Originally Posted by rhackenb
I bought a 4 battery emergency charger for my Archos PMA430 (together with a lot of other stuff for my Archos) from here:
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?targ...ategory_id=301
Has anyone heard of anything like this with a 2mm plug?
-- rhackenb
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.
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2007-03-07
, 22:24
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Posts: 355 |
Thanked: 9 times |
Joined on Feb 2007
@ Helsinki, Finland
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#17
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Have you checked out: www.solio.com? I have one and it works great. Never without a charge for my iPod, phones, N800, etc....
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2007-03-07
, 22:58
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Posts: 84 |
Thanked: 6 times |
Joined on Feb 2007
@ Noblesville, IN USA
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#18
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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
-- rhackenb
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2007-03-08
, 00:12
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Posts: 3,220 |
Thanked: 326 times |
Joined on Oct 2005
@ "Almost there!" (Monte Christo, Count of)
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#19
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Originally Posted by rhackenb
Nokia makes a 3.5 to 2 mm adapter. Expansys has it:
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?
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
). 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.