I've had some trouble in the past with getting a white buildup around the negative terminal of the battery in my rodeo ute. I have always been able to get it going again, but it has always been some fiddling around when it gets bad.
When this happened the second time I bought a new battery terminal and put it in the car. Ready for me to install it. However because the problem didn't come back I didn't end up getting it installed.
Yesterday I had the same problem. I park on a slope at work and there is enough electricity getting through the terminal to hill start it, which I did. However when I got home there wasn't even enough getting through to run the central locking. So I had to fix it.