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2010-08-26
, 07:55
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Posts: 118 |
Thanked: 202 times |
Joined on Aug 2010
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#22
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Hi,
I've written two scripts to help automate the process of switching the batteries. Seems to work ok.
(1) swapbat.sh
#!/bin/sh
#disable cell
dbus-send --system --type=method_call --dest=com.nokia.phone.SSC \
/com/nokia/phone/SSC com.nokia.phone.SSC.set_radio boolean:false
#stop battery manager
sudo stop bme
sleep 1
#lock screen/keyb
dbus-send --system --type=method_call --dest=com.nokia.mce /com/nokia/mce/request \
com.nokia.mce.request.req_tklock_mode_change string:"locked"
echo
echo "Screen locked, please wait about 20s until LED remains orange."
echo "Then replace battery. Be careful not to press any buttons."
echo
This script turns off phone modem, screen/keyboard and battery manager. You have to wait until the orange LED remains on ("emergency autonomous charge mode"). By that time the system will have "settled" and won't draw a lot of power. Then you can switch the battery.
(2) swapbatdone.sh
#!/bin/sh
#enable cell
dbus-send --system --type=method_call --dest=com.nokia.phone.SSC /com/nokia/phone/SSC \
com.nokia.phone.SSC.set_radio boolean:true
#restarting battery manager
sudo start bme
sleep 1
#resetting screen
dbus-send --system --type=method_call --dest=com.nokia.mce /com/nokia/mce/request \
com.nokia.mce.request.req_tklock_mode_change string:"locked"
sleep 1
dbus-send --system --type=method_call --dest=com.nokia.mce /com/nokia/mce/request \
com.nokia.mce.request.req_tklock_mode_change string:"unlocked"
echo ..done
Turns cell modem and battery manager back on, then resets screen to finish process.
These could be bound to the power button menu, so you don't need to slide out the keyboard.
To anyone willing to test these scripts, usual disclaimer applies: I can't guarantee these scripts won't fry your battery, your phone or your dog.
Last edited by nephridium; 2010-08-26 at 08:19. Reason: fixed long lines in code
I've written two scripts to help automate the process of switching the batteries. Seems to work ok.
(1) swapbat.sh
#!/bin/sh
#disable cell
dbus-send --system --type=method_call --dest=com.nokia.phone.SSC \
/com/nokia/phone/SSC com.nokia.phone.SSC.set_radio boolean:false
#stop battery manager
sudo stop bme
sleep 1
#lock screen/keyb
dbus-send --system --type=method_call --dest=com.nokia.mce /com/nokia/mce/request \
com.nokia.mce.request.req_tklock_mode_change string:"locked"
echo
echo "Screen locked, please wait about 20s until LED remains orange."
echo "Then replace battery. Be careful not to press any buttons."
echo
This script turns off phone modem, screen/keyboard and battery manager. You have to wait until the orange LED remains on ("emergency autonomous charge mode"). By that time the system will have "settled" and won't draw a lot of power. Then you can switch the battery.
(2) swapbatdone.sh
#!/bin/sh
#enable cell
dbus-send --system --type=method_call --dest=com.nokia.phone.SSC /com/nokia/phone/SSC \
com.nokia.phone.SSC.set_radio boolean:true
#restarting battery manager
sudo start bme
sleep 1
#resetting screen
dbus-send --system --type=method_call --dest=com.nokia.mce /com/nokia/mce/request \
com.nokia.mce.request.req_tklock_mode_change string:"locked"
sleep 1
dbus-send --system --type=method_call --dest=com.nokia.mce /com/nokia/mce/request \
com.nokia.mce.request.req_tklock_mode_change string:"unlocked"
echo ..done
Turns cell modem and battery manager back on, then resets screen to finish process.
These could be bound to the power button menu, so you don't need to slide out the keyboard.
To anyone willing to test these scripts, usual disclaimer applies: I can't guarantee these scripts won't fry your battery, your phone or your dog.
Last edited by nephridium; 2010-08-26 at 08:19. Reason: fixed long lines in code
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2010-08-26
, 08:04
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Posts: 118 |
Thanked: 202 times |
Joined on Aug 2010
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#23
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Argh, just found with those scripts it will not always enter into "emergency power mode" - maybe someone knows why?
Back to the drawing board...
Last edited by nephridium; 2010-08-26 at 08:26.
Back to the drawing board...
Last edited by nephridium; 2010-08-26 at 08:26.
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2010-10-02
, 21:57
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Posts: 1,258 |
Thanked: 672 times |
Joined on Mar 2009
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#24
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So the "emergency power mode" has limited power available.
In the interest of experimentation, I modified the script I normally use for bme-less operation for hotplug.
Even with 1250mA current available from the charger, which is significantly more than the 950 or so that N900 will use by default, and more than twice as big as the amount available in "emergency power mode", there's not enough power to cover hotplug with the cellular radio active.
The moment I try connect to GPRS, or there's traffic on gprs, the device goes down.
So, hotswap without offline mode does not seem possible. The energy buffers left in N900 after removing the battery aren't big enough. Not even when "overclocking" the charger.
In the interest of experimentation, I modified the script I normally use for bme-less operation for hotplug.
Even with 1250mA current available from the charger, which is significantly more than the 950 or so that N900 will use by default, and more than twice as big as the amount available in "emergency power mode", there's not enough power to cover hotplug with the cellular radio active.
The moment I try connect to GPRS, or there's traffic on gprs, the device goes down.
So, hotswap without offline mode does not seem possible. The energy buffers left in N900 after removing the battery aren't big enough. Not even when "overclocking" the charger.
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2010-10-03
, 06:21
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Posts: 4,930 |
Thanked: 2,272 times |
Joined on Oct 2007
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#25
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Originally Posted by joerg_rw
Crazy question: how about a dongle with a capacitor across the VBUS/GND leads, and a switch on D+/D-? It'd be bulkier, but if it works it would simplify the procedure a bit...
In The Field Hotswapping:
You need a dongle *) that has two slots for contacting 2 BL-5J batteries, a 2way switch, and a 1000uF 6.3V capacitor. And a USB-A-receptacle with D+/- short plus CA-101, or a charger-cable stub.
[edit] Depending on component variance this might not work with voltage of empty battery, so some sort of booster might be needed to step up voltage of even an empty battery to a reliable V-IN(min) level of >4.0V for BQ24150
I haven't been messing with the OTG/host hackery, but I'm under the impression the charge pump works fine, so it seems you could charge the capacitor over a minute or two, turn off the charge pump and transition to low-power state, then wait for the user to flip the switch to initiate charging/battery-swap procedure.
Assuming an average draw of 200mA, a duration of 25 seconds, and a range from 5V to 4V, we need a 5F capacitor; 2x 10F 2.5V ultracaps in series should serve nicely enough; sparkfun shows these at Φ13×33.5mm.
__________________
World's first inductively-charged N900!
World's first inductively-charged N900!
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2010-10-03
, 10:21
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Posts: 2,222 |
Thanked: 12,651 times |
Joined on Mar 2010
@ SOL 3
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#26
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Originally Posted by Benson
You wouldn't need any switch. My original idea predating original post here was along same lines, but by using a small LiIon or 3..4 NiMH button cells
Crazy question: how about a dongle with a capacitor across the VBUS/GND leads, and a switch on D+/D-? It'd be bulkier, but if it works it would simplify the procedure a bit...
I haven't been messing with the OTG/host hackery, but I'm under the impression the charge pump works fine, so it seems you could charge the capacitor over a minute or two, turn off the charge pump and transition to low-power state, then wait for the user to flip the switch to initiate charging/battery-swap procedure.
Assuming an average draw of 200mA, a duration of 25 seconds, and a range from 5V to 4V, we need a 5F capacitor; 2x 10F 2.5V ultracaps in series should serve nicely enough; sparkfun shows these at Φ13×33.5mm.
Of course a capacitor may work as well, the calculation seems correct
:-D
/j
__________________
Maemo Community Council member [2012-10, 2013-05, 2013-11, 2014-06 terms]
Hildon Foundation Council inaugural member.
MCe.V. foundation member
EX Hildon Foundation approved Maemo Administration Coordinator (stepped down due to bullying 2014-04-05)
aka "techstaff" - the guys who keep your infra running - Devotion to Duty http://xkcd.com/705/
IRC(freenode): DocScrutinizer*
First USB hostmode fanatic, father of H-E-N
Maemo Community Council member [2012-10, 2013-05, 2013-11, 2014-06 terms]
Hildon Foundation Council inaugural member.
MCe.V. foundation member
EX Hildon Foundation approved Maemo Administration Coordinator (stepped down due to bullying 2014-04-05)
aka "techstaff" - the guys who keep your infra running - Devotion to Duty http://xkcd.com/705/
IRC(freenode): DocScrutinizer*
First USB hostmode fanatic, father of H-E-N
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2011-05-13
, 09:52
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Posts: 5,028 |
Thanked: 8,613 times |
Joined on Mar 2011
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#27
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Originally Posted by shadowjk
Sorry for resurrecting century-old thread, but can You tell me how (software-wise, i assume) overclocking the charger work? It is just disabling BME before/after plugging charger, or what?
So the "emergency power mode" has limited power available.
In the interest of experimentation, I modified the script I normally use for bme-less operation for hotplug.
Even with 1250mA current available from the charger, which is significantly more than the 950 or so that N900 will use by default, and more than twice as big as the amount available in "emergency power mode", there's not enough power to cover hotplug with the cellular radio active.
The moment I try connect to GPRS, or there's traffic on gprs, the device goes down.
So, hotswap without offline mode does not seem possible. The energy buffers left in N900 after removing the battery aren't big enough. Not even when "overclocking" the charger.
In some situations it would be nice to charge with values close to 1C.
Also i got chargers with much more mA available @ 5V, but charging battery with for example 10C would be not very nice
so i would like to see detailed background info about "what does what" in You method, if You would kindly*...*Obvious bioshock easter egging
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2011-05-13
, 13:47
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Posts: 1,258 |
Thanked: 672 times |
Joined on Mar 2009
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#28
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Howto "overclock" charger has not been published. Though the information is available in datasheets to technically skillful people.
I used to use higher charge rates, but went back to maemo defaults.
The efficiency seems to drop off quite alot at higher rates, making the phone heat up to 50-60Centigrade.
In the end it only cuts 15-30 minutes from charge time..
I discovered datasheets of the battery in N900 (A Samsung cell, forgot the link), which specified 0.7C max charge rate 0.5C recommended, iirc.
The battery I did subject to 1.2A charging lost more capacity in 50 cycles than another brand new nokia original in 100 cycles @ 0.7C..
I used to use higher charge rates, but went back to maemo defaults.
The efficiency seems to drop off quite alot at higher rates, making the phone heat up to 50-60Centigrade.
In the end it only cuts 15-30 minutes from charge time..
I discovered datasheets of the battery in N900 (A Samsung cell, forgot the link), which specified 0.7C max charge rate 0.5C recommended, iirc.
The battery I did subject to 1.2A charging lost more capacity in 50 cycles than another brand new nokia original in 100 cycles @ 0.7C..
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2011-05-14
, 05:22
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Posts: 5,028 |
Thanked: 8,613 times |
Joined on Mar 2011
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#29
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Thank You for info.
I got some nice (at least seems to be nice) idea for mid-easy hardware mood, allowing hotswap battery in field without any additional elements outside phone (no dongles etc), without need to disabling bme, dropping connections, etc... Should work even with very high load on phone. Probably will need mugen cover - due to case free space limitations - but can be easily used in parallel with 3000 mAh battery mod.
I wan't to do some test to be sure that it's not dangerous in any way to hardware (nothing indicate that it can be, but i want to test it myself before publishing on forum), but what i need now is resistance toleration range for 3th pin probed by bme to check if battery is in place.
Yea, i know i can check it myself with couple of adjustable resistors - it's what I'm going to do if anyone won't be able to help - but it's little PITA process, so if anyone know ~ range (no need to be very precise), it would certainly help a lot.
Especially, that joerg_rw work on jrbme probably made him test it already, to replicate bme behavior...
// Edit
I assume that bme probe third pin to ground resistance? I.e third pin to middle pin resistance? (Or Am i totally wrong on this?) Checked resistance of battery, 100k OHM in my case. Logic tells that resistance can't be too high (when no battery is present, resistance between 3th pin and ground pin is infinite), we know that bme isn't too picky about resistance, cause thermo-resistors changing resistance during work are accepted without flaws - is there any limitation in how low resistance can get? That's most critical to my mod design.
Last edited by Estel; 2011-05-14 at 09:05.
I got some nice (at least seems to be nice) idea for mid-easy hardware mood, allowing hotswap battery in field without any additional elements outside phone (no dongles etc), without need to disabling bme, dropping connections, etc... Should work even with very high load on phone. Probably will need mugen cover - due to case free space limitations - but can be easily used in parallel with 3000 mAh battery mod.
I wan't to do some test to be sure that it's not dangerous in any way to hardware (nothing indicate that it can be, but i want to test it myself before publishing on forum), but what i need now is resistance toleration range for 3th pin probed by bme to check if battery is in place.
Yea, i know i can check it myself with couple of adjustable resistors - it's what I'm going to do if anyone won't be able to help - but it's little PITA process, so if anyone know ~ range (no need to be very precise), it would certainly help a lot.
Especially, that joerg_rw work on jrbme probably made him test it already, to replicate bme behavior...
// Edit
I assume that bme probe third pin to ground resistance? I.e third pin to middle pin resistance? (Or Am i totally wrong on this?) Checked resistance of battery, 100k OHM in my case. Logic tells that resistance can't be too high (when no battery is present, resistance between 3th pin and ground pin is infinite), we know that bme isn't too picky about resistance, cause thermo-resistors changing resistance during work are accepted without flaws - is there any limitation in how low resistance can get? That's most critical to my mod design.
Last edited by Estel; 2011-05-14 at 09:05.
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2011-05-14
, 14:48
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Posts: 1,258 |
Thanked: 672 times |
Joined on Mar 2009
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#30
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As resistance goes lower, the battery meter assumes smaller and smaller battery.
However, the battery meter only checks it on boot.
No idea about range, but the default is indeed 100kOhm between GND and BSI (third pin).
However, the battery meter only checks it on boot.
No idea about range, but the default is indeed 100kOhm between GND and BSI (third pin).
And yeah, bme will be terminating charge later on two BL-5J in parallell.
In general there's no problem connecting Li-Ions in parallell, as long as they are at same state of charge when the connection is made.