Solar Power

The battery pack I made for my telescope a while back needed to be kept charged.  I prefer to keep it in the telescope shed rather than taking it into the house to recharge.  So I bought an 18V photovoltaic panel and hung it in the west window of the shed to charge.  While it is an 12VDC output, the cigarette lighter plug seems to limit output to 13.3VDC which is good to avoid overcharging the battery.  I think this means that I do not need a battery charge controller to prevent overcharging.  (I have one if I need it.)  I needed a 12VDC extension to get enough length.  

Yes, I know adhesive tape is not terribly good in heat.  I suppose I will loosen a couple of those screws holding the window in place and find a way to secure the panel.