Posted by Eeyore on October 7, 2008, 10:32 am
Simple. You need more than 12V to charge a 12V battery.
Posted by Gordon on October 7, 2008, 10:18 pm
What kind of voltage reading do you get with somthing plugged
in? It is possible that you are trying to draw too much
from the panal.
Posted by spaco on October 12, 2008, 11:00 pm
Since you make the point that your "soldering is correct", I'll assume
that you are new to electronic stuff.
First: Are you reading the 12 volts with an analog multimeter or a
digital multimeter? An analog meter may not be sensitive enough to tell
you whether you are getting 12.0 volts or 12.5 volts.
You will need something like at least 12.7 volts to send current
into a car battery.
Second: I assume that you are reading the +12 volts at the center
terminal of the socket with the red multimeter lead. This should be
correct for most negative ground cars.
Are you reading the 12 volts with the battery connected? If so,
disconnect the battery and read the "raw" voltage right from the solar
panel. If it is a panel designed to CHARGE a 12 volts battery, then its
open circuit voltage, in BRIGHT SUN should be at least 15 or 15 volts
and maybe as much as 20 volts. If this is NOT the case, then you have
the wrong solar panel for the job.
How do you know that no charging is occurring? It could be that the
battery is already fully discharged or defective and that your small
panel's output is only slowly doing anything.
Posted by Eeyore on October 14, 2008, 11:23 pm
Ignore everything else this IDIOT has said.
Posted by spaco on October 15, 2008, 2:45 am
I am surprised that you thought it necessary to comment as you did.
What was wrong with my post that set you off?
Please be specific so I won't make the same mistakes again. I am a
little new to PV, but I've been around electronics and batteries for
over 60 years.
I have seen many inexpensive analog multimeters that have only about
one meter needle distance on the scale between one "volt" and the next.
Add to that a possible inaccuracy problem in the divider resistors,
and the problem I detail can easily occur, especially to someone who may
be in the learning mode.
If the OP IS experienced in this field, and was affronted by my advice,
he/she should contact me off list to discuss the issue farther.