I think I have a charging problem.
System and voltages
I have a 100 watt
solar panel charging my
battery. When I measure the voltage at connection from
solar panel to charge controller I get 19+ volts. When I check connection from
battery to charge controller I get about 13.4 volts. So far, so good.
Possible Problem
Yesterday the voltage dropped down to about 12.9 volts on
battery side. The battery
light on the charge controller was fast blinking which means the battery is fully charged. So this looked like a problem because the voltage is usually in the 13+ volts when fully charged.
This morning, the
light was on solid indicating battery was charging. Voltage read about 13.4 volts. I just checked again and voltage has dropped to 12.9 volts and
light is fast blinking again.
I'm at a loss how to trouble shoot this. The only things I can think of are:
- Possible intermittent short in one of the connectors or cables
- Intermittent failure in charge controller
Any ideas on what else might be causing this problem or things to measure?
ETA: I turned the fan on and disconnected the
solar panel. I wanted to see if the battery light on charge controller would change to solid when the battery was discharged some. So far, it is still fast blinking and voltage has dropped from about 13.3 to 12.95.
ETA 2: With fan on, voltage dropped quickly to about 12.8. The light changed back to solid on, so I hooked
solar panel back up. Voltage jumped to about 14.1. After a couple of minutes, battery light changed to fast blink again.
Maybe this is just how a cheap charge controller works.
New problem is why is fan pulling down voltage so fast?