small solar panel regulator?

I always thought it wasn't necessarily current (except for wet cell deep cycles batteries) but voltage that can cause problems, thus my yellow top AGM has very specific instructions that it not ever be charged over a certain voltage, 14.something, but nothing mentioined on how restrictions as to amphours.

Solar Panels are constant current devices - they'll put out 18 volts on open circuit (or a multimeter that draws miniscule current) - they'll put out 13 volts if you connect it to a 6 cell battery - 6.5 volts of you connect it to a 3 cell battery - 2.2 volts if you connect it to a 1 cell battery.