GTA02 Battery Capacity (Was: Re: More about the GTA02)

[joerg]

Am Do  28. Februar 2008 schrieb Uncle Kridley:
> Michael Shiloh wrote:
> > There will be a charger for the Neo Freerunner, which has the secret
> > resistor jOERG mentions below.
> 
> Does this mean that it won't charge (or will only charge slowly) from a
> generic USB connector/charger?  Part of the point of USB charging is
> that you don't need a proprietary charger for every device you own.  If
> the Freerunner won't charge off generic USB, I'll be sad.

Though i have no clue what's really going on with this, there are some facts 
that might help imagine:
- USB-clients (like NEO in charge mode) may pull 100mA from a USB-host. 
With advertising (i guess, via some USB-data protocol), a device may increase 
allowable current to 500mA. However many clients break this spec, by either 
not advertising or drawing >500mA. 
- Everything over 500mA is considered illegal and may (also _should_ not) 
damage host USB adapters. (there are chances to kill a laptop USB port with 
external HD-drives! If both are sloppy designed)
- For quick charge purposes, NEO might well take 1 - 2 A from USB adapter. 
However extreme care should be taken not to "smoke up" a poor designed host.

So maybe: 
- charge from any host (incl simplistic chargers): 100mA (6-12h)
- charge from "intelligent" host: 500mA (1-2h)
- charge from quickcharger with magic R: 1500mA (<1h)
Switching to fast and/or ultrafast charge mode possible also with prev. 
mentioned script.

jOERG