Re: batery posts
Torcano - disconnect the battery cables from the battery posts. Clean the inside of the terminal clamp and likewise clean the battery posts. (You're probably already aware that there are battery terminal cleaning wires brushes sold at most auto parts stores just for this purpose.) If there are bolts and nuts on the terminal, pull them off too, clean them up and coat them with dielectric grease. Some terminal clamps are crimped and molded onto the end of the battery cable, and some are clamped on. If yours are clamped on then disassemble it, clean it, grease it and reassemble. Then apply a liberal amount of dielectric grease to every surface on the battery post and the terminal clamp. Again, the dielectric grease is sold at any auto parts store. Then attach the terminal back onto the post.
In short, take every single metal piece apart, clean it totally, cover it with dielectric grease and then reassemble. If you do a good job you will have years of good service with no problems. Also, keep the top and outside of your battery clean to reduce leakage paths. Keep the water level topped off every now and then and you can forget about the battery and concentrate on the good stuff like fishing, playing with the kids, and cruising around for fun.

By the way, dielectric grease also does a great job on the contacts of the bulbs in your trailer lights. (Unless you have LEDs.) Regards - Woodnaut