Using off-brand solar panels with Mighty Mule gate opener

[Sleeper]

I have a mighty mule gate opener (model MM600) that can be powered by an 18vac solar panel from 5W to 30W... and the company sells 5W and 10W panels, but they are very expensive compared other brands. Can I purchase other brands of solar panels rated 6W-18W and install them straight to the controller board (has terminals for solar or transformer power input of 18V). The purpose of the solar panel (or transformer from wired power) is to trickle charge the 12V lawn mower battery that actually opens and closes the gate.

Link to gate opener manual with diagrams of controller board...
http://www.mightymule.com/wp-content/uploads/MM600-Manual-07-06-2010.pdf

 

[Bluejets]

Can't see any problem with that.

 

[Sleeper]

Thanks. Do I need to match the 18V of the controller board (i.e., match it with a solar panel that is rated 18V), and do I need to match the 2200mA that the transformer (is rated at?). I assume that I should do both (at least try to get close on mA)? Thanks in advance for humoring basic questions.