Update: Charging MP3 Player, Coby MP620-4G
in [Repair]
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From: jaugustine on 10 Mar 2010 07:39 Hi, Since my original post, I bought the Coby MP620-4G MP3 player. The OM says to use a "high power" USB port (computer). There is no other information in the OM or at their web site on a recommended charging current if using a different source. I can set the maximum current limit on my lab quality regulated power supply. Note: There is no connection to the USB "data" pins with this setup. The MP3 player display indicates that it was "charging". When I first charged this MP3 player at 200 MA max, which didn't take very long before the display said the battery is "charged", I loaded it with several hundred songs (MP3). It played for a little over an hour then the player "died" (no warning). I recharged it at 100 MA max and it played over 5 hours, but I didn't run it until it "died". Again, when I charged it at 200 MA max, which didn't take long, it played for 1hr and 10 minutes, then "died". For the second time, I charged it at 100 MA max, and it plays a long time. John PS, Remove "ine" from my email address
From: William R. Walsh on 10 Mar 2010 13:46 Hi! > The OM says to use a "high power" USB port (computer). ....or self powered hub (one with a power adapter that plugs into it. > When I first charged this MP3 player at 200 MA max, which didn't > take very long before the display said the battery is "charged" > I recharged it at 100 MA max and it played over 5 hours This tells me that the owner's manual is wrong, at least in part. 100mA is the maximum amount of current a USB host is supposed to provide without the attached device requesting more, up to 500mA. Some do, some don't. Without any data pins in the connector, I do not think there is a way for this player to tell the host what it wants in terms of current delivery. (The lack of data pin wiring is surprising. How are you expected to put songs on the player?) The behavior of the player also suggests that its charging circuit becomes confused when additional current is provided to it, and as a result, it reports the battery being fully charged before it is. Perhaps if it were allowed to remain plugged in even after reporting a "full" charge, it would finish charging the battery by way of a slow charge. William
From: Michael A. Terrell on 10 Mar 2010 18:27 jaugustine(a)verizon.net wrote: > > Hi, > Since my original post, I bought the Coby MP620-4G MP3 player. > The OM says to use a "high power" USB port (computer). There is > no other information in the OM or at their web site on a recommended > charging current if using a different source. > > I can set the maximum current limit on my lab quality regulated > power supply. Note: There is no connection to the USB "data" pins > with this setup. The MP3 player display indicates that it was "charging". > > When I first charged this MP3 player at 200 MA max, which didn't take > very long before the display said the battery is "charged", I loaded it with > several hundred songs (MP3). It played for a little over an hour then the > player "died" (no warning). > > I recharged it at 100 MA max and it played over 5 hours, but I didn't run > it until it "died". Again, when I charged it at 200 MA max, which didn't take > long, it played for 1hr and 10 minutes, then "died". > > For the second time, I charged it at 100 MA max, and it plays a long time. A USB port is supposed to provide 500 mA max. -- Greed is the root of all eBay.
From: JW on 11 Mar 2010 05:13 On Wed, 10 Mar 2010 18:27:13 -0500 "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote in Message id: <4B982AD1.D3BDE48D(a)earthlink.net>: > >jaugustine(a)verizon.net wrote: >> >> Hi, >> Since my original post, I bought the Coby MP620-4G MP3 player. >> The OM says to use a "high power" USB port (computer). There is >> no other information in the OM or at their web site on a recommended >> charging current if using a different source. >> >> I can set the maximum current limit on my lab quality regulated >> power supply. Note: There is no connection to the USB "data" pins >> with this setup. The MP3 player display indicates that it was "charging". >> >> When I first charged this MP3 player at 200 MA max, which didn't take >> very long before the display said the battery is "charged", I loaded it with >> several hundred songs (MP3). It played for a little over an hour then the >> player "died" (no warning). >> >> I recharged it at 100 MA max and it played over 5 hours, but I didn't run >> it until it "died". Again, when I charged it at 200 MA max, which didn't take >> long, it played for 1hr and 10 minutes, then "died". >> >> For the second time, I charged it at 100 MA max, and it plays a long time. > > > A USB port is supposed to provide 500 mA max. According to the specification, yes. However, I've seen motherboards that connect +5V directly to the USB port.
From: Michael A. Terrell on 11 Mar 2010 13:10
JW wrote: > > On Wed, 10 Mar 2010 18:27:13 -0500 "Michael A. Terrell" > <mike.terrell(a)earthlink.net> wrote in Message id: > <4B982AD1.D3BDE48D(a)earthlink.net>: > > > > >jaugustine(a)verizon.net wrote: > >> > >> Hi, > >> Since my original post, I bought the Coby MP620-4G MP3 player. > >> The OM says to use a "high power" USB port (computer). There is > >> no other information in the OM or at their web site on a recommended > >> charging current if using a different source. > >> > >> I can set the maximum current limit on my lab quality regulated > >> power supply. Note: There is no connection to the USB "data" pins > >> with this setup. The MP3 player display indicates that it was "charging". > >> > >> When I first charged this MP3 player at 200 MA max, which didn't take > >> very long before the display said the battery is "charged", I loaded it with > >> several hundred songs (MP3). It played for a little over an hour then the > >> player "died" (no warning). > >> > >> I recharged it at 100 MA max and it played over 5 hours, but I didn't run > >> it until it "died". Again, when I charged it at 200 MA max, which didn't take > >> long, it played for 1hr and 10 minutes, then "died". > >> > >> For the second time, I charged it at 100 MA max, and it plays a long time. > > > > > > A USB port is supposed to provide 500 mA max. > > According to the specification, yes. However, I've seen motherboards that > connect +5V directly to the USB port. IBM did that with the keyboard on their original XT motherboard, with no fuse. I had a customer's keyboard cable short at the keyboard. If he hadn't been at the computer when it happened, it would have set his house on fire. There was nothing but a few pieces of bare, burnt wire left. Do those motherboards have self resetting fuses? If not, there is no way I would use them or let anyone else get their hands on them. -- Lead free solder is Belgium's version of 'Hold my beer and watch this!' |