Re: Charging with external battery - possible?
 

That is not clear to me.
Isn't it up to the device to draw it's desired current? The charger cannot choose both voltage and current.
Are you saying that the charger is expected to enforce the 950mA current limit? I thought the device would do that.
OK, it is making a bit more sense as I think about it.

Re: Charging with external battery - possible?
 

i use a sonyo eneloop externel battery http://www.eneloop.info/index.php?eI...729fcc5b6fc3a1

that has 2usb out ports. Using an Y-usb cable from a external harddrive with an adapter to micro usb i get up to 1000 mA out of the battery which seems to charge the N900 the same way the Nokia charger does, at least according to batterygraph. The battery has 2000mAh and was about 35€ on amazon, the adapter and the Y-cable should be about 10€. And my impression is that the battry holds the charge without much loss, i left it for about two weeks in my pocket and the recharged th N900 one time without a problem.

Re: Charging with external battery - possible?
 

No, my main goal is to be independent from charging-possibility for some days. Okay - I could buy me about 20 of them...

Let`s see, for how long 3 AA Alkaline run the device...

Re: Charging with external battery - possible?
 

From my observations of N8x0, the charge regulation is done through a slow PWM (about 1Hz). Even if the software set it to the lowest, 1/255, there'd still be a huge current flowig into the battery for 4msecs every second or so..

Re: Charging with external battery - possible?
 

You seem to be under the impression that primary cells last longer. That was true once, but I believe that rechargeables now have a greater capacity than alkalines.
The 1.8V lithium AAs have good capacity, but are expensive.
If you want to keep the weight down, just use Li-Ion.

Re: Charging with external battery - possible?
 

actually, a few days ago i saw a tv-report on useful gadgets, and they were testing a solar-charger. it was basically just like the official external charger form nokia, just that you dont load that on the wall, but by the sun. and even though it was cloudy, it was loading the battery with full 5V.
i guess its worth a try.

i think the other dead sure solution would be one of those devices you have to wind up to generate electricity. takes a lot of time though...^^

Re: Charging with external battery - possible?
 

Li-Ion vs alkaline is a nobrainer, Li-Ion wins.. In extremely low-drain situations, it might be a dead race..

Not sure about the situation with primary 3.6V lithiums.. But I'd be nervous about using those anyway due to safety..