solar panel

[TuxTrax]

Hi all

I have a seimens 10 watt solar panel I bought on ebay used. I know
that solar panels have a definite life expectancy, and that when you
buy them used, you don't know how much good service you can expect
from them.

I bought it anyway, because the price was very affordable.

My question is this: In full direct sunlight, my multimeter reads 17.9
volts output from the panel, at zero milliamps. I don't understand
this reading. It is powering the internal electronics of the charge
controller it is connected to, and the charge controller requires a
few milliamps if I recall. Is my multimeter giving me a bad reading?

Any help is greatly appreciated. My email addy is bogus, any response
should be publicly posted. Thank you,

Mathew

 

[Rheilly Phoull]

"TuxTrax" <arctic@tuxtrax.com> wrote in message
news:10d9011b.0406010019.27c76d9d@posting.google.com...

Hi all

I have a seimens 10 watt solar panel I bought on ebay used. I know
that solar panels have a definite life expectancy, and that when you
buy them used, you don't know how much good service you can expect
from them.

I bought it anyway, because the price was very affordable.

My question is this: In full direct sunlight, my multimeter reads 17.9
volts output from the panel, at zero milliamps. I don't understand
this reading. It is powering the internal electronics of the charge
controller it is connected to, and the charge controller requires a
few milliamps if I recall. Is my multimeter giving me a bad reading?

Any help is greatly appreciated. My email addy is bogus, any response
should be publicly posted. Thank you,

Mathew

Due to the internal resistance etc of the panel the voltage will drop as you
load it up (they can be shorted out without harm).
When it is connected to say a 12v battery which is what I would say it is
designed for you will see the volts drop to just above the battery terminal
volts.
That will slowly rise as the battery charges, probably up to 14volts.

--
Regards ........... Rheilly Phoull

 

[SB]

Make sure you use a solar controller!! don't hook the panel directly up to
the battery....and also, be sure to use some series diodes to stop the
battery from draining back (if you don't use the controller).



"Rheilly Phoull" <Rheilly@bigpong.com> wrote in message
news:2i2up9FierslU1@uni-berlin.de...

"TuxTrax" <arctic@tuxtrax.com> wrote in message
news:10d9011b.0406010019.27c76d9d@posting.google.com...
Hi all

I have a seimens 10 watt solar panel I bought on ebay used. I know
that solar panels have a definite life expectancy, and that when you
buy them used, you don't know how much good service you can expect
from them.

I bought it anyway, because the price was very affordable.

My question is this: In full direct sunlight, my multimeter reads 17.9
volts output from the panel, at zero milliamps. I don't understand
this reading. It is powering the internal electronics of the charge
controller it is connected to, and the charge controller requires a
few milliamps if I recall. Is my multimeter giving me a bad reading?

Any help is greatly appreciated. My email addy is bogus, any response
should be publicly posted. Thank you,

Mathew

Due to the internal resistance etc of the panel the voltage will drop as
you
load it up (they can be shorted out without harm).
When it is connected to say a 12v battery which is what I would say it is
designed for you will see the volts drop to just above the battery
terminal
volts.
That will slowly rise as the battery charges, probably up to 14volts.

--
Regards ........... Rheilly Phoull