#touchbook IRC Log


IRC Log for 2010-11-13

Timestamps are in GMT/BST.

[0:53] * MMlosh (~MMlosh@2001:470:1f0b:b78:60b8:deed:8161:43a6) has joined #touchbook
[1:06] * phcoder (~phcoder@131-82.62-81.cust.bluewin.ch) Quit (Quit: Leaving.)
[1:07] * phcoder (~phcoder@131-82.62-81.cust.bluewin.ch) has joined #touchbook
[1:15] * MatthiasF (~Matthias@2a01:e35:2e79:e590:217:31ff:feb6:acf3) has joined #touchbook
[1:18] * phcoder (~phcoder@131-82.62-81.cust.bluewin.ch) Quit (Ping timeout: 264 seconds)
[1:18] * MatthiasF (~Matthias@2a01:e35:2e79:e590:217:31ff:feb6:acf3) Quit (*.net *.split)
[1:18] * mjr (mjr@aulis.sange.fi) Quit (*.net *.split)
[1:20] * MatthiasF (~Matthias@2a01:e35:2e79:e590:217:31ff:feb6:acf3) has joined #touchbook
[1:29] * Noume (~Noume@f050064054.adsl.alicedsl.de) has joined #touchbook
[1:33] * phcoder (~phcoder@ has joined #touchbook
[1:35] * apropos (~apropos@89-168-184-101.dynamic.dsl.as9105.com) has joined #touchbook
[2:12] * avacore (~avacore@1008ds1-rdo.0.fullrate.dk) has joined #touchbook
[4:00] * apropos (~apropos@89-168-184-101.dynamic.dsl.as9105.com) has left #touchbook
[4:13] * Martix (~martix@4.177.broadband3.iol.cz) has joined #touchbook
[4:43] * MMlosh (~MMlosh@2001:470:1f0b:b78:60b8:deed:8161:43a6) Quit (Quit: Bye...)
[4:45] * mjr (mjr@aulis.sange.fi) has joined #touchbook
[4:52] <Mrkva> hmm
[4:58] <Mrkva> when I connect battery directly at the 8 pin connector the battery can be drained almost to 0 (capacity, not voltage), but then I've got problem with charging (charging circuitry shuts itself down for ap
[4:58] <Mrkva> approx. 10 secs each minute or so
[5:00] <Mrkva> alhough there's no (well, almost none) curren flowing through the new connection
[5:05] <Mrkva> Martix: I guess you were right about that current sensing resistor
[5:10] * phcoder (~phcoder@ Quit (Quit: Leaving.)
[5:10] <Martix> FYI its R15 on bottom board
[5:12] <Mrkva> hm
[5:12] <Mrkva> I've just noticed it shuts down in regular intervals even without that new wire connected
[5:13] <Mrkva> Martix: the bottom charger ciruit schematics is also available?
[5:13] <Mrkva> Martix: or you've reversed it? :)
[5:36] * MMlosh (~MMlosh@2001:470:1f0b:b78:5c35:72a8:29c6:c0b8) has joined #touchbook
[5:49] <Mrkva> in case anyone knows, whats U2 on the bottom battery charger? if i read it correctly, the label on it says "CIA TI BCK A7FK" but I can't find datasheet anywhere
[6:08] <Martix> Mrkva: I just followed circuit on the board
[6:09] <Mrkva> Martix: and there's only one?
[6:11] <Mrkva> because it should belong to BQ27200. and it's only a "fuel gauge", not controlling anything. so reason for shutting down must be something else
[6:15] <Mrkva> and by the way, I've squeezed of it 11hrs with wifi active, cpu maxed out, usually with display at max brightness
[6:30] * phcoder (~phcoder@gprs45.swisscom-mobile.ch) has joined #touchbook
[6:52] * MMlosh (~MMlosh@2001:470:1f0b:b78:5c35:72a8:29c6:c0b8) Quit (Quit: Bye...)
[7:34] <Maeslin> actually discharging a li-ion battery that low is a Very Bad Thing (tm) and the reason it won't charge is that both its internal protection circuit and the TBs charger chip won't allow it and will go in 'bad battery' mode very quickly
[7:34] <Maeslin> on some batteries that state is irreversible. The protection circuit basically blows an internal fuse
[7:36] <Maeslin> I would be very surprised if you had a 200mV drop at the current sense resistor, the BQ27200 mandates a 0.02 Ohm value for it
[7:37] <Maeslin> to get a 200mV drop on that low a resistor, you'd need to draw 10 amps out of the battery
[7:37] * phcoder (~phcoder@gprs45.swisscom-mobile.ch) Quit (Ping timeout: 240 seconds)
[7:37] <Maeslin> in which case it would be flat after barely one hour
[8:01] <Mrkva> Maeslin: the battery protection circuitry should not allow draining more energy from the battery than it's safe. of course, complete power cycling Li-ion/Li-pol should be avoided where possible - but I was just testing it. and battery should last at least 1000 complete cycles
[8:02] <Mrkva> Maeslin: I'm not saying I had a 200mV drop at that resistor
[8:03] <Mrkva> I'm saying I have approx 400mV drop at cables/connectors
[8:16] * phcoder (~phcoder@ has joined #touchbook
[8:58] * MMlosh (~MMlosh@2001:470:1f0b:b78:d9ce:51a5:b8b5:4fb8) has joined #touchbook
[9:13] <Maeslin> oh ok
[9:13] <Maeslin> and yeah, I misread your earlier message
[9:13] <Maeslin> thought you meant draining it to 0V
[9:14] <Mrkva> Maeslin: no, that would kill the baterry for sure
[9:14] <Maeslin> draining it to zero power would still give you about 3.something volts
[9:14] <Maeslin> if the charger chip is a 'modern' TI, it goes in trickle-charge mode if the battery voltage is too low
[9:15] <Maeslin> to try to get the voltage back up to a safe level before going through a regular charge cycle
[9:15] <Maeslin> there's a timeout to it, so if it stays below safe voltage for too long in trickle-charge mode the charger chip considers the battery to be bad and stops
[9:16] <Mrkva> I'm not sure, I think the LiPol can be discharged to 2.7-3V depending on the cell. I've stopped at 3.05 approx
[9:17] <Maeslin> let me check
[9:18] <Maeslin> working on li-ion charger circuits right now so the trickle-charge threshold voltage should be pretty much the same across all chargers that have that feature
[9:18] <Maeslin> since it's dependent on battery chemistry
[9:22] <Maeslin> hm
[9:22] <Maeslin> from what I can see, it should be around 2.9 to 3.2V
[9:23] <Maeslin> anything below that voltage and the charger would go in precharge mode instead of 'normal'
[9:24] <Maeslin> I've had to resurrect a cellphone battery like that before, its voltage was so low that the voltage stayed below the safe threshold for too long and the charger would just stop
[9:25] <Maeslin> I basically had to put the battery in, wait 5 minutes for the charger to time out, pull the battery out and repeat
[9:25] <Maeslin> until its voltage rose up enough for the charger to start working normally again
[9:25] <Mrkva> hmm, thats not the issue. it's charging normally right now :)
[9:25] <Maeslin> took me about four hours.
[9:25] <Maeslin> oh ok :p
[9:26] <Mrkva> Maeslin: ah, that must have been funny
[9:26] <Mrkva> :)
[9:27] <Maeslin> nah the fun part was taking the damn thing appart and doing surface mount work with a regular soldering iron
[9:27] <Maeslin> to replace the micro-USB connector that had been sheared off
[9:27] <Maeslin> (hence why the battery was so low in the first place)
[9:28] <Maeslin> so wait, the keyboard charger shuts itself down for about 10 seconds every minute or so?
[9:29] <Maeslin> or the tablet charger?
[9:30] <Mrkva> keyboard
[9:30] <Mrkva> Maeslin: regular soldering iron? you mean that really old with a wire loop?
[9:31] <Maeslin> no I mean an actual iron instead of a hot air rework station
[9:31] <Mrkva> ah
[9:32] <Maeslin> it's tricky work when the finest iron tip available is about 20 times larger than the pins you have to work on
[9:33] <Mrkva> yeah, I can imagine that
[9:33] <Mrkva> you need a really steady hand
[9:35] <Maeslin> no coffee for me that day. :p
[9:36] <Mrkva> :)
[9:58] * kennyz0 (~kennyz@uralnet.org) Quit (Remote host closed the connection)
[10:23] * kennyz (~kennyz@uralnet.org) has joined #touchbook
[10:26] * MatthiasF (~Matthias@2a01:e35:2e79:e590:217:31ff:feb6:acf3) Quit (Remote host closed the connection)
[10:32] * MatthiasF (~Matthias@2a01:e35:2e79:e590:217:31ff:feb6:acf3) has joined #touchbook
[10:38] * tommd (~Thomas_Du@c-24-20-220-27.hsd1.or.comcast.net) has joined #touchbook
[11:58] * MMlosh (~MMlosh@2001:470:1f0b:b78:d9ce:51a5:b8b5:4fb8) Quit (Quit: Bye...)
[12:27] * phcoder (~phcoder@ Quit (Ping timeout: 245 seconds)
[12:29] * phcoder (~phcoder@ has joined #touchbook
[14:30] * `Assassin (~blank@71-8-56-51.dhcp.leds.al.charter.com) has joined #touchbook
[14:43] * Noume (~Noume@f050064054.adsl.alicedsl.de) Quit (Ping timeout: 260 seconds)
[14:56] * tommd (~Thomas_Du@c-24-20-220-27.hsd1.or.comcast.net) Quit (Quit: Leaving.)
[15:03] * Martix (~martix@4.177.broadband3.iol.cz) Quit (Ping timeout: 255 seconds)
[15:34] * MatthiasF (~Matthias@2a01:e35:2e79:e590:217:31ff:feb6:acf3) Quit (Remote host closed the connection)
[16:16] * htitan (~dad@65-102-162-25.tukw.qwest.net) has joined #touchbook
[16:18] * Marex (vasum7am@u-pl15.ms.mff.cuni.cz) Quit (Quit: leaving)
[19:22] * The_Ringmaster (~The_Ringm@static-173-53-191-192.chi01.dsl-w.verizon.net) has joined #touchbook
[19:22] * phcoder (~phcoder@ Quit (Ping timeout: 276 seconds)
[19:35] * phcoder (~phcoder@185-118.203-62.cust.bluewin.ch) has joined #touchbook
[19:45] * htitan (~dad@65-102-162-25.tukw.qwest.net) has left #touchbook
[22:47] * The_Ringmaster (~The_Ringm@static-173-53-191-192.chi01.dsl-w.verizon.net) Quit (Quit: Goodbye for now.)
[23:58] * Martix (~martix@4.177.broadband3.iol.cz) has joined #touchbook

These logs were automatically created by TouchBook-LogBot on irc.freenode.net using the Java IRC LogBot.