If this acid overflow has happened to your cart you need to do one more thing to prevent another issue. Acid and cart frames do not go well together. In fact if you have a cart like mine with an aluminum frame the acid and aluminum will turn into this white stuff that is so hard you may need a chisel to get it off. If this has happened you may need to hire someone unless you are comfortable puling the batteries, washing everything and putting them back.... big/heavy job...
Hopefully This may not have happened yet.
Someone needs to clean the cart and battery tray/rails. I have used this stuff in the past as it is easier than baking soda IMO:
Walmart.com: NOCO 14oz Battery Cleaner and Acid Detector: Automotive
Do this on the grass, not your driveway or street as the acid will stain. It will not hurt the grass.
Spray the can or three all over the sides of batteries and tray/rails. It will turn pink when it finds acid. Be careful to not spray too much on top of battery as you would hate for it to get into battery.
Then you simply wash off with a hose set on a gentle spray.
It is a pain in the butt, but letting acid sit on the frame may be a bigger pain in the butt later.....