Battery cable terminals are constructed with a rope strand of copper wire wrapped in a color-coded rubber compound. Swollen cables can indicate that battery acid or road salts have entered into the terminal and caused corrosion. Frequently clean the cables to keep them free of corrosion. In addition, avoid overfilling the cells and/or overcharging the batteries, which can have just as detrimental effect as under filling the cells or allowing the batteries to drain past 50% state of charge. Overfilling and overcharging can cause excess battery acid to boil out the cells and onto the battery terminals.
Worn or corroded battery cables can cause problems with the RV electrical system. If the RV is experiencing hard starting or no start, this may also signal a problem with the battery cable terminals.
It is not necessary to disconnect the cables when adding water to liquid lead acid battery cells, but each time the batteries are serviced a thorough cleaning and inspection of the battery cable terminals should be performed. AGM and Gel Cell battery cable terminals should be maintained at least one time per month while the RV is in use.
Service of the battery cable terminals includes careful inspection of the rubber jacket. Cuts or breaks that cause frayed cables must be immediately replaced. Check the battery posts and clear away corrosion by scrubbing with a wire brush and a solution of 50/50 baking soda and water. Remember to wear safety glasses when performing this procedure. For heavier build-up, use a battery cleaning solution available at most auto parts stores. Rinse with clear water, tighten the connections and apply a coating of high-temperature grease.
When changing batteries or removing a cable, first turn the ignition off and disengage the automatic generator start. Sketch a drawing to note the position of the battery cables prior to disconnecting. Unhook the negative before the positive, and when reconnecting, hook the positive before the negative. Place the removed terminals on a clean flat surface that provides adequate space to prevent contact between the rings.
Use the usual precautions when working around battery cables. Disengage the battery disconnect switch, remove all metal jewelry and wear eye protection to guard against splashed electrolyte.
When additional terminals are added to the battery it is important to pay attention to the placement of the ring terminal. Heat shrink tubing on smaller rings will act as an insulator and prevent proper contact for larger rings. Position the big cable first, followed by the smaller cable on top and then any connectors you may use, such as for the solar panel, on top of that. Be sure rubber tubing only covers the barrel of the terminal and is not pinched under the bolts and covering any part of the conductive surface.
Cleaning the Battery Terminals
1. Remove the battery cables from the battery terminals by loosening the nut on each cable clamp. Once they are loose, always remove the cable clamp from the negative terminal first. It’s marked with a minus (-) sign; the positive terminal has a plus (+) sign. Reverse the procedure, positive first, negative second, when replacing the cables. The cable may not come off easily. You will have to wiggle it and lift it upward until the clamp comes off the terminal post. Be careful not to short any tools you use against the car when they’re in contact with the battery.
2. Examine the battery cables and clamps for excess wear or corrosion. Should damage appear extensive, replace the cables and clamps to avoid future problems.
3. Check the battery case for cracks and the terminals for damage. If you find either, replace the battery.
4. Secure the loose cables so that they don’t accidentally flop back onto the terminals.
5. Pour some baking soda directly onto the posts.
6. Dip a toothbrush in water and use it to scrub the baking Soda into the terminal posts and cable clamps. Skin and eye protection are recommended.
7. If the toothbrush isn’t doing the job, Use a battery terminal cleaner brush on it. Also shine up the insides of the cable clamps by using the clamp cleaner that usually comes attached to the terminal brush or use a plain, soap-free steel wool pad.
8. Dry everything off with a clean, disposable, lint-free rag.
9. Cover all exposed metal surfaces on the battery posts, battery cables, and clamps.
10. Replace the positive clamp first and then replace the negative clamp. Tighten them down with the proper sized wrench.
11. Replace the rubber boot or plastic shield that covers the positive terminal. If you don’t have one, go and buy some from your local auto parts store.