THE ROCK BATTERY DESIGN Durability: Some battery designs are simply more durable than others. They are more forgiving in abusive conditions, i.e.; they are less susceptible to vibration or shock damage, over charging and deep discharge damage. Gel cell batteries are the most likely to suffer irreversible damage from overcharging. Flooded acid batteries are the most likely to suffer from internal shorting and vibration damage. Rock Advanced AGM batteries are more durable and can withstand severe shock and vibration as well as fast charging. Efficiency: This comparison is critical. Internal resistance of a battery denotes its overall charge/discharge efficiency, its ability to deliver high cranking currents without significant drops in voltage and is a measure of how well it has been designed and manufactured. For flooded wet cell batteries, internal resistance can be as high as 26%. Gel cell batteries are comparably better at only approximately 16% internal resistance and require only roughly 116% of rated capacity to be fully charged. Rock Advanced AGM style batteries have the lowest internal resistance of any battery manufactured, only 2%. This allows them to be charged much faster if needed and also to deliver higher power when required. Battery Criteria Comparisons: Most buyers like to make comparisons by using various specifications and measurements. Common comparison criteria include Cold Cranking Amps or CCA, which is a clear indicator of a battery’s ability to start an engine. Reserve minutes depict a battery’s ability to deliver current at steady rates from a fully charged condition down to 10.5 volts and are expressed in minutes, i.e. xx reserve minutes at 25 amp discharge. Life Cycles are used to measure longevity or how many times a battery can be discharged in its life time at set levels.