On 7/6/2022 5:38 PM, J. P. Gilliver (John) wrote:
> On Wed, 6 Jul 2022 at 13:15:57, Robert in CA <
magin...@yahoo.com> wrote (my responses usually FOLLOW):
>> I've had it plugged into the 8500 for an hour now
>> and there's no indicator that it's charging. I had the
>> power off though. However I turned the power on
>> and still no indicator light.
>>
>> It did the same thing with the charger for my digital
>> camera.
>
> What's the rating of that charger? It'll probably say, though in tiny black on black. If significantly less than 1A (which Paul found was what your device wants), it might shut down to protect itself.
>>
>> I know this is a dumb question but should I have the
>> power on the portable cd when charging? That's
>> what I have it set at now but I see no signs of it charging.
>
> Well, one obvious thing to try ... (-:
>>
>> Maybe it needs to fully charge before the light comes on?
>
> Maybe. Try connecting it in a darkened room - does its light flash even briefly when you connect it? Try with it both turned on and off. (I'd expect that in most cases it would charge either way, but charge faster when it's turned off.)
>
> Does the unit have any sort of indication of its battery (really cell)'s charge level - battery symbol in its display with segments, for example? If so, is it going up or down?
>>
>> Robert
Normally, there should be a LED showing two states.
One state indicating "charging", a second
state indicating "done".
Then, when the charging cable is disconnected, the LED will go out entirely.
A lucky thing in this case, is the player uses a single
cell 3.7V LiCo. This means the charger cannot refuse to
charge it, because the cell voltage is too low. Those
will charge from zero, like my digital camera with one cell
does. So at least it won't have the safety enabled, as
reverse bias is not possible when only one LiCo is present.
I would guess the device is "moody" :-) And wants to
see a port with strapping indication.
If you own a USB power meter (an in-line device)
https://www.amazon.ca/X-DRAGON-Multimeter-Chargers-Capacity-Accuracy/dp/B019RHJRM8/
you can see how much current flows. If a device draws little
to no measured current, the thing is moody. If the device draws
900mA, it's probably charging. If you see the current decline,
you are in Phase 2 top-op and charging continues until the
current flow level drops to 3% or so (27mA). Some USB power
meters have more digits for the measurement, than others
(dynamic range issue).
The first charging phase is done at constant current, so
then 900mA may flow. The second phase, it switches to
constant voltage (4.2V) and the charge controller inside
the player watches the current drop, until it hits 3-5%
of full current. That's a kind of tapered charge at the end.
So you could watch the whole process, with a USB power meter.
The USB Power meter would even work with the charger brick -
just put the meter in-line, the player on the end, and watch
it go.
There are many models of USB power meters. Some include
measurement of USB-C connectors. USB-C uses a variety
of voltages and currents, and is not limited to just 5V.
The meter then, if used with USB-C, could indicate
higher voltages are in use.
But you don't need to buy a USB-C power meter for this
particular job. Just a regular simple meter would suffice.
Anyway, that's how a "scientist without a solder iron" would
check it :-)
Paul