[all/fso?] external battery "just mobile gum pro" woes

[arne anka]

i just bought an external battery, just mobile gum pro (4400 mAh,Input  
(Mini USB): 5VDC 500mA Min; output (USB Type A Port): 5VDC 1000mA) to keep  
the fr alive even when using gps hours on end.

last night i tried to load the fr, when starting the fr was at 48% --  
after 11h it was at 69%.
looking at openmoko-panel-plugin's battery view, the state oscillated  
between "charging" and "not charging".
the pwr led however firmly stayd orange, indicating charging (switching  
the batter yoff almost immediately made the led going blue, so it's not  
just inertia).

sending the fr to suspend and charging, brought the level to 100% in maybe  
two hours (that's when i checked again).

so, does anyone experience similar issues with an external battery? and  
what could probably cause that oscillation (and how to stop that of  
course)?


[1]  
http://www.amazon.com/4400mAh-External-Battery-Portable-Devices/dp/B001BWQTOC/ref=sr_1_1/187-9838094-3791553?ie=UTF8&s=miscellaneous&qid=1253622704&sr=8-1

ps: just to see which kind is not line broken ...
> http://www.amazon.com/4400mAh-External-Battery-Portable-Devices/dp/B001BWQTOC/ref=sr_1_1/187-9838094-3791553?ie=UTF8&s=miscellaneous&qid=1253622704&sr=8-1
<http://www.amazon.com/4400mAh-External-Battery-Portable-Devices/dp/B001BWQTOC/ref=sr_1_1/187-9838094-3791553?ie=UTF8&s=miscellaneous&qid=1253622704&sr=8-1>