Battery Myths and the Real Truth

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We are often asked questions by our customers and batteries have evolved which leads to thoughts which were once true to now be myths. Saying that, I thought it would be a good idea to share a list of traditional battery myths followed by the truth.

 

 #1: Storing a battery on a concrete floor will discharge them.

Myth: In the past, when battery cases were made out of wood, the rate of discharge was accelerated. Today, battery cases are made of polypropylene or hard rubber which seal better and allow discharge to no longer be a problem. **Suggestion: Top of battery should be kept clean and keep the battery at a cool temperature because temperature stratification within large batteries can accelerate the internal “leakage” or self-discharge when sitting on a floor that is too cold or too warm.

 

 #2: Driving a car will fully recharge a battery.

Myth: Late model and especially ISS vehicles have ‘smart’ alternators that are controlled by the engines computer systems. The average state of charge of the battery in these vehicles is rarely over 75% and driving longer makes little difference. The days of ‘going for a drive’ for an hour, to charge the battery are gone. The only way to fully recharge is to use a quality, mains powered charger

 

 #3: A battery can explode.

Truth: A wet, lead acid battery produces hydrogen and oxygen gasses. However, the vent caps in batteries help prevent explosions that occur when jumping, connecting or disconnecting charger/cables, and starting the engine. Keep in mind that a battery explosion will most likely cause an eye and burn injury rather than create a Hollywood building explosion scenario.  It is very important that all sparks, flames, and heat sources are nowhere near a battery that is charging or being cycled and always wear the appropriate personal protective equipment when working near batteries.

 

#4: “Maintenance Free” batteries never require maintenance.

Myth:  What happens to water on roads, in cups, etc. during summer? Evaporation! The same thing occurs in batteries. In hot climates, the water in the electrolyte can evaporate due to the high under-hood temperatures. Therefore, non-sealed batteries can be a benefit in hot climates because you can easily add distilled water when evaporation occurs.  Many maintenance-free, or sealed, batteries are designed so that the gas vented during charging collects and is “recombined” back into the battery. The best maintenance is good and proper charging.

 

#5 A larger capacity battery will damage my car.

Myth: A starter motor will only draw a fixed amount of current from the battery, based on the resistance of the load. A larger current capacity battery supplies only what is required but will give you more starting capacity and will not damage your car but will last longer due to lest DoD.

 

#6: Flooded, AGM, and Gel batteries are the same.

Myth: Even though all AGM, GEL, and flooded batteries are classified as lead acid, the internal construction of the battery divides them into their respective categories. AGM are the latest batteries. AGMs are sealed and use a separator consisting of fiberglass between the plate to hold electrolyte in its place with capillary action, however Flooded or ‘wet cell’ batteries are the most common. Flooded batteries use the lead plates, sulfuric acid electrolyte, and plate separators but the acid flows free within the battery. Gel batteries are also sealed like AGM. However, unlike an AGM, they use a silica material to turn the sulphuric acid into a jelly like substance. This jelly is then used as the electrolyte. Gels are best in Deep Cycle applications.

 

#7: Trickle charger is the best way to charge my car battery

Myth: No, not very effective. One should charge the battery at 10% to 13% of the battery’s 20 hour AH capacity. Most vehicles are rated between 50-110 amp hours. Automatic trickle chargers are good to keep the battery charged in storage or for small batteries like those used for Powersports applications

 

#8: After leaving the car’s lights on, going for a drive will recharge the battery

Myth: No, you will not fully recharge the battery by going for a drive. In fact ‘surface’ charging or continuous undercharging will lower the capacity of the battery over time and shorten its life. You will also void the warranty by not recharging it correctly. The best way to restore a flat dead battery is to use an appropriate multi-stage good quality battery charger.

 

 #9: Tap water can be used to top off the water level in a battery if the plates are exposed.

Myth: To replace lost water in batteries, use distilled, deionized, or demineralized water. Tap water can produce mineral build-up on the plates of the battery.

 

#10: The bigger the cold cranking amps (CCA), the better the battery.

Myth: The electrical systems on most cars are designed around a specific size battery. The vehicle’s computer systems regulate the power required for normal operation. The electrical system will only use a fixed amount of power from the battery based on the requirements of the starter motor and electrical system. A large CCA battery only supplies what is required. While it won’t damage your car, it can cause some strange issues in high tech vehicles.