SOME MYTHS ABOUT BATTERIES
A. Storing a battery on a concrete floor will discharge them.
Modern lead acid battery cases are better sealed, so external leakage causing discharge is no longer a problem. [Temperature stratification within large batteries can accelerate the internal "leakage" or self discharge if the battery is sitting on an extremely cold floor in a warm room.]
B. Driving a car will fully recharge a battery.
There are a number of factors affecting alternator's ability to charge a battery.The greatest factors are how much current from the alternator is diverted to the battery to charge it, how long the current is available and temperature.Generally, running the engine at idle or short "stop-and go trips" during bad weather at night will not recharge the battery.
C. A battery will not explode.
While spark retarding vent caps help, recharging a battery produces hydrogen and oxygen gasses.Battery explosions can also occur when the electrolyte level is below the top of the plates. If a spark or flame occurs, an explosion will occur.
D. A battery will not lose it's charge sitting in storage.
A battery has self discharge or internal electrochemical "leakage" that will cause it to become fully discharged and sulfated over time.Prior to storing a battery, it should be fully charged, placed in a cool location above freezing, and recharged when it reaches the 80% state-of-charge level or once every six months, whichever occurs first.If left in a vehicle, disconnect the negative cable.
E. Maintenance free batteries never require electrolyte.
In hot climates, the electrolyte could be "boiled off" due to the high underhood temperatures.Electrolyte could also be lost due to excessive harging voltage or charging currents.
F. Test the alternator by disconnecting the battery with the engine running.
A battery is like a voltage stabilizer or filter to the pulsating DC
produced by the alternator. Disconnecting a battery while the engine is running can destroy the electronic components, e.g., computers, radio, stereo, alarm system, etc., or the charging system. Just say NO! if anyone suggests this.
'93 300E 4Matic
'98 Nissan Altima
'00 Yamaha Road Star Silverado