04:45 <Oksanaa> How sensitive is neo900 (and its battery-charging chip) to ambient temperatures? Because in some places the ambient temperatures routinely reach 40°C. Just how much does it affect battery and electronics?

06:42 <wpwrak> Oksanaa: dunno about effects on battery life and such, but the electronics generally withstand temperatures of, at the very least, 70 C.

06:44 <wpwrak> so i wouldn't leave it anywhere i myself wouldn't like spending an hour (intense sunlight, etc.), but heat that humans can survive will not even begin to trouble it

06:57 <wpwrak> plastics will deform (badly) long before any electronics have trouble

06:57 <wpwrak> now, if i could just find that picture i have of my laptop passing the plastic's melting point ...

07:13 <wpwrak> here we go: https://neo900.org/stuff/werner/tmp/meltdown.jpg

07:15 <wpwrak> the deformed keycaps had to be pushed really hard to work. so by now most of them have cracked and i'm typing on the "nipples" under the keycaps. the electronics still work perfectly.

08:50 <Oksanaa> wpwrak: problem is, battery charger DT-33 does not work perfectly. Details earlier on #maemo .

14:42 <DocScrutinizer05> LiIon start a runaway process as early as 70°C, that's why all decent batteries and charger circuits have some form of overtemperature shutdown

14:49 <DocScrutinizer05> originally the PTC/NTC resistor on the third battery contact been used for such purposes in all LiIon based devices. Over time it turns out the battery doesn't produce high delta-temperature/time gradients, so it's sufficient to place the temp sensor close enough to the battery to sense the temperature of complete system

14:53 <DocScrutinizer05> can't comment on DT-33, never seen one

14:55 <DocScrutinizer05> but I seem to recall it has a shutdown that kicks in after 1024mAh of energy deposited into battery

15:02 <DocScrutinizer05> Oksanaa: ^^^^

15:09 <DocScrutinizer05> for some background see http://people.openmoko.org/joerg/battery/PACK950925.pdf specifically page 64 for allowable cell temperature range

15:10 <DocScrutinizer05> cell temperature range for charging specified there as 0°~45°C

15:12 <DocScrutinizer05> given there's probably only a loose coupling between cell temperature and what any temp sensor in DT-33 can detect, requesting SAFE charging in ambient temperatures of 30°C might simply not be feasible

15:13 <DocScrutinizer05> it also might be the case that thermal design of the DT-33 is somewhat sloppy

15:13 <DocScrutinizer05> and thus errs on the safe side rather that setting your house on fire