On Fri, Aug 14, 2009 at 12:11 AM, Ed Kapitein<[email protected]> wrote: >> I hope we can collaborate, collect useful data and publicate >> them. Im very tired all these cheap half-finished electrical >> devices (I can only charge 27% from a 3500mAh 3.7V >> accumulator! It is insane!) >> > i think 3.7 V is just not enough to charge the freerunner, in need to be > 5.5V if i am not mistaken. >> I also want to collect the *efficiency* of the charger backed up >> with some measured data.
The charger itself internally has two 3.7V Li-Ion battery parallel connected. There is an internal circuit with some DC-DC converter to deliver the correct 5V output. The problem is, that FreeRunner's battery is 3.7V 1200mAh(4.44Wh), that charger's battery is 3.7V 3500mAh(12.95Wh), so no matter how efficient the internal DC-DC converter it should charge at least once the freerunner. (with 50% efficiency we still have 3.7*3.5*0.5 = 6.48Wh power what the Freerunner get at the end). So if it cant charge the Freerunner at least once, something is seriously fucked up design-wise. Best regards, Laszlo _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
