Monthly Archives: July 2016

Batteries and Charging System

First of all, what does your car battery really do?

  • The battery supplies power to the starter and the ignition system to start the engine.
  • The battery supplies the extra power necessary when the vehicle’s electrical load exceeds the supply from the charging system.
  • The battery acts a voltage stabilizer for the electrical system. The battery evens out voltage spikes and prevents them from damaging expensive electrical components.

batteries and charging systemSecondly, how does your battery work? Don’t stop reading yet, I’ll keep this short and sweet (without all the technical jargon). A battery consists of positive and negative plates arranged alternately within a plastic case then submerged in sulfuric acid and water and lastly sealed shut. Small vents are incorporated into the top of the case to release any gases that may be produced. The electrolyte (acid mixture) causes a chemical reaction that produces electrons, aka ELECTRICITY. When an electrical device is used, electrons are drained from the battery. The alternator (or generator, as many folks call it) replaces the used power by “recharging” the battery. See, now that wasn’t so bad was it?
As we continue to place more demand on batteries and electrical systems with…

  • Cell phone equipment
  • Anti-theft devices
  • Elaborate Audio systems
  • Entertainment systems – DVD
  • Laptop Computers

It’s even more important to pay attention to a battery’s care and maintenance. Picture 1 shows a battery in its natural environment, under the hood (on most vehicles – some have been found in the trunk, behind the fender splash shield or even under the backseat). All batteries age and eventually die. The average life span of a battery is 37 months. 30% of all automotive batteries make it to 48 months.

What causes premature failure in batteries?

  • Deep discharges (leaving lights on, glove box light stays on etc.)
  • Vibration – it’s in a moving object, hard to get away from this one. Make sure all battery mounting hardware is in place and in good condition.
  • Fast Charging – using the super cycle on your charger instead of the trickle charge setting or possibly a faulty voltage regulator.
  • Overcharging – possibly an alternator problem.
  • HEAT – The number one cause of premature battery failure in cars is loss of water from high under hood heat or overcharging.

How hot does it get? I couldn’t find any exact figures on just how hot it gets under the hood so I did my own little study. I took my own 300C and put a fluke tester on the intake runner and shut the hood. After ten minutes sitting at an idle on a 65° day, the temperature had already climbed to 151°. I’m guessing after several hours of highway driving the numbers get much higher even with the use of cooling fan modules. How does the water get out, it’s a sealed unit? Remember the vents in the top cover of the battery? When batteries are severely overheated, liquid acid spews out of the vent openings. Small amounts of acid vent out and cause