Scenario:
Already existing autogate system power by main and battery backup.
Goal:
To have the autogate system powered by Solar and battery backup.
What I understand is I can get a solar panel and solar charge controller to charge the battery.
25W panel with 10A PWM charge controller would suffice. The issue is now how can I do it.
Anyone done this before? Care to share how?

Haha..been in that situation twice so far. Did not expect the battery gone kaput so soon so went back home and found blackout in the area and my gate won't open. Lucky not with family so can panjat pagar setel.
So the battery backup can't use larger voltage?