We had some power woes with one of the electric fences, which reminded me on the pain I had initially trying to keep the rabbit fence electic fence running.
I’ve writtten up an article on the care and feeding of farm 12V batteries to save other smallholders some of that pain. You have to look after your batteries if you want to get a decent service life out of them. You also need to dimension the capacity right, lead acid batteries hate being thrashed by using too much of the battery capacity.