Support and General Use > Hardware
iriver H320 + 32GB CF-Card + 2200mAh Battery - some problems
littlenick:
My conclusion is drawn from the following observations:
1) When iriver original firmware shuts down the player due to low battery, rockbox gives me another 4 hours of playback.
2) Right after iriver's original firmware shutdown there is enough juice left that even the high draw of the HDD during reboot leaves the voltage somewhere in the 3.6 V -area.
3) The funny clicking sound on shutdown after restart would never occur immediately after iriver's original firmware shutdown, i.e. the safety margin in iriver's threshold seems to be ample.
soap:
--- Quote from: littlenick on September 26, 2010, 02:26:31 PM ---My conclusion is drawn from the following observations:
--- End quote ---
While I (obviously) can't disagree with your observations, I find your conclusions are not supported by them:
--- Quote from: littlenick on September 26, 2010, 02:26:31 PM ---1) When iriver original firmware shuts down the player due to low battery, rockbox gives me another 4 hours of playback.
--- End quote ---
This in and of itself is as likely a commentary on iRiver as it is Rockbox.
--- Quote from: littlenick on September 26, 2010, 02:26:31 PM ---2) Right after iriver's original firmware shutdown there is enough juice left that even the high draw of the HDD during reboot leaves the voltage somewhere in the 3.6 V -area.
--- End quote ---
Considering 2.7-3.0 volts is safe discharge level, I think point #2 tips your first point towards iRiver being overly conservative.
--- Quote from: littlenick on September 26, 2010, 02:26:31 PM ---3) The funny clicking sound on shutdown after restart would never occur immediately after iriver's original firmware shutdown, i.e. the safety margin in iriver's threshold seems to be ample.
--- End quote ---
I don't see the connection, much less the conclusion, especially given #2.
dreamlayers:
There are two separate requirements here:
* 1) A need to protect the battery from overdischarge.
* 2) A need to shut down while the device is still able to operate.
Multiple sources say that 3.0 V is a safe shutdown voltage with lithium polymer batteries. If after restarting after a low battery shutdown, the battery voltage is 3.04V, then Rockbox clearly satisfies the first requirement.
The clicking on shutdown makes me wonder about the second requirement however. Maybe iRiver decided to shut down the device at a higher voltage because the device cannot operate reliably at lower voltages? There's another issue however: as a battery ages, its internal resistance increases, and this causes voltage to dip more during load spikes such as hard disk activity.
littlenick:
I vaguely remember reading (but don't remember where) that the hdd needs 3.2 Volts to operate.
Well - you developers surely checked the requirements of the toshiba hdd before programming the threshold.
Still a battery that gives me over 10 hours of playback with original firmware does not seem completely shot to me.
dreamlayers:
Is the hard drive powered by a switching power supply which is capable of boosting voltage?
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