10w solar panel problem
Have had a 125w panel on my camper for 12 years. Just put camper on its jacks after traveling. Noticed a couple of days later that battery voltage down. Looked at controller and no charging happening.
Remembered I had a new 10w panel (Voc=21.76) in the garage. Hooked it up direct to battery with no controller late afternoon. Battery was 12.4v before connecting panel. Next morning, with hazy sun on panel, battery was 12.1v. Disconnected panel from battery and voltage went up to 12.2v.
Output of disconnected panel was around 10v. I know I saw 18v from disconnected panel when checking polarity before wiring everything up. The panel is intended exactly for what I'm trying to do. I also did the same thing with another 7w panel on my boat for years.
Is it possible to damage a panel by shorting the 2 output leads together? Was the panel draining the battery w/o any sun on it? There is no mention in the panel description of a blocking diode, but also no mention of needing one or a controller.
Thanks,
Remembered I had a new 10w panel (Voc=21.76) in the garage. Hooked it up direct to battery with no controller late afternoon. Battery was 12.4v before connecting panel. Next morning, with hazy sun on panel, battery was 12.1v. Disconnected panel from battery and voltage went up to 12.2v.
Output of disconnected panel was around 10v. I know I saw 18v from disconnected panel when checking polarity before wiring everything up. The panel is intended exactly for what I'm trying to do. I also did the same thing with another 7w panel on my boat for years.
Is it possible to damage a panel by shorting the 2 output leads together? Was the panel draining the battery w/o any sun on it? There is no mention in the panel description of a blocking diode, but also no mention of needing one or a controller.
Thanks,
