Battery Basics & Maintenance
Uncle Al's Tech Tips of the Week
The information in this tech tip is to educate UTC staff and ensure customer satisfaction and safety.
Today’s tech tip provides general information while staying true to purpose. The lead acid battery has been used commercially for over 100 years. The same chemical principle that’s being used to store energy is basically the same as our great grandparents used.
A battery is like a piggy bank — as you use electricity from it you must put it back. That’s the function of a truck’s alternator. Present day chassis battery power requirements are huge. Consider today’s trucks and all the electrical devices that must be supplied with power. All these electronics and accessories require a reliable source power, and poor battery condition can cause expensive electronic component failure. The lead acid battery is made up of plates, lead, and lead oxide, with a 35% sulfuric acid and 65% water solution. This solution is called electrolyte, which causes a chemical reaction that produces electrons or electricity. Over time as the battery charges and discharges the lead plates deteriorate and the battery slowly dies. Temperature and vibration can also can adversely affect battery life.
Understanding the 2 most common types of truck batteries:
- Wet cell (flooded), The wet cell comes in two styles: serviceable and maintenance free. Both are filled with electrolyte and are basically the same. You can add water to the serviceable battery and check the specific gravity of the electrolyte with a hydrometer. The maintenance free wet cell is the most common; you do not add any water and they are sealed. (The wet cell maintenance free batteries are generally used at our UTC locations for the trucks’ main electrical systems).
- The gel cell and the AGM batteries are specialty batteries that typically cost twice as much as a premium wet cell battery. However, they store and cycle electricity longer and do not tend to degrade as easily as the wet cell. They are the safest lead acid batteries you can use. Gel cell and AGM batteries are recommended for axillary application. Examples include to power the No Idle HVAC systems, in sleeper trucks because of extra electrical load (such as in International’s Maxpower No Idle System). The AGM would also be a good fit for medium duty application with electric liftgates, etc.
Battery Life and Performance: Average battery life has become shorter as a truck’s energy requirements have increased. Two phrases I hear most often are “my battery won’t take a charge,” and “my battery won’t hold a charge.” Only 30% of batteries sold today reach the 48-month mark. In fact 80% of all battery failure is related to sulfation build-up. This build-up occurs when the sulfur molecules in the electrolyte (battery acid) become so deeply discharged that they begin to coat the battery’s lead plates. Before long the plates become so coated that the battery dies.
Battery Maintenance: A properly maintained battery is important for the ultimate in service life. Consider these points on a regular basis:
Safety first: When doing electrical work on trucks, it’s best to disconnect the ground cable. Just remember that you’re messing with corrosive acid, explosive gases and hundreds of amps of electrical current.
- The battery should be cleaned using a baking soda and water solution; a couple of tablespoons to a pint of water (this will neutralize any acid that might be present).
- A serviceable battery needs to have the fluid level checked. Use only mineral-free water; distilled is best as all impurities have been removed and there is nothing left that could contaminate your cells.
- Cable connections need to be cleaned and tightened as battery problems are often caused by dirty and loose connections. (Very common problem)
- To prevent corrosion of cables on top-post batteries, use a small bead of silicone sealer at the base of the post and place a felt battery washer over it. Coat the washer with high temperature grease or petroleum jelly (Vaseline), then place the cable on the post and tighten. Coat the exposed cable end with the grease. The gases from the battery condensing on metal parts causes most corrosion.
- Keep your batteries charged. With the key turned off there is a higher Parasitic drain on newer trucks, especially with trucks not driven daily. These range from engine control modules to body controller and other accessories that can drain the batteries.
Note: To maximize battery life, reduce costs and increase truck performance it’s important to keep electrical components, battery boxes, and the engine in top condition, and to minimize or eliminate electrical loads when the engine is not running. (Refer to you specific truck’s operators manual for detailed battery and electrical system maintenance.)