Can I use a regulator from a car to regulate the voltage from a solar panel to a battery?
solar panels will naturally produce a certain DC voltage which is what your battery needs - the current will vary based on the sun light. You need probably 4V to have some over voltage. So based on your specs look at having at least 4 V but not too much over that (tells you how many panels you need in series) I would have blocking diodes (probably the solar cell has them built in) to insure the battery does not discharge thru the panel.
