battery bulge is caused by wear-and-tear lead sulphate deposits collecting between the plates, in larger and larger amounts. it is hastened by chronic under-charging.

white terminal deposits are due to a leak around the battery terminals. these leaks may be caused by housing cracks brought about by improper terminal tightening and loosening techniques.
they can also be caused by electrolyte (acid) vapors escaping from the battery vents. they are pronounced by overcharging.