I have a 2006 precedent and when I got new batteries,someone told me to pull the cover from the OBC and look for corrosion. I did so and there was a lot on the bottom. I knocked off as much as I could . If I am careful, can I use a mixture of baking soda/water to spray on the bottom-- being sure not to get any on anywhere else? Or is there another way to remove it? 
I am new to golf cart care, and have done a lot of searching on how to care for it, but could not find anything about this.
Thanks for any ideas.