Gel Cell Battery

[G.R.]

Deep cycle, ie. Optima yellow and blue tops and others of the same ilk are "deep cycle" batteries. They do not like rapid charge-discharge cycles, like most automotive alernators provide,they like a steady step-down charge through a voltage regulator. Deep cycle batteries are usually for use in the marine and RV environment, for use to power "house"needs, like refrigeration, cabin lights and such when the engine/generator is offline. They tolerate very "deep" discharges and properly re-charged can last for years.

It is not that the battery is "bad" in and of itself but that it was used for the wrong purpose that it was intended. Just because a battery is rated@ 700-1000CCA does not mean it is the right battery for the use intended. CCA is only an indictator of the batterys capacity.

AGM type are a very good choice for automotive use, similar to gell cell in that they are a sealed battery and can be mounted in most any position, something that can't be done with lead-acid batterys.

I would never use a deep cycle battery in a car and expect it to last for more than a year or so

I sailed and lived aboard for several years. My "house bank", the batterys used to power cabin lights, anchor lights, other demands, refrigeration/heat etc., were "deep cycle", the single start battery for the engine was a sealed AGM type. I had twin 100 amp alternators run through a step-down regulator. When the engine was run the alternators would initally rapid charge then the regulator would begin to kick in and start "stepping" down the input voltage until the batterys went into a "float" stage whereby the alternators input current provided the batterys with only as much current as they needed to come to a full charge, generally around 2-5 amps input.

Automotive alternators just rapid charge all the time so one needs a battery that can handle that, ie. some quality lead-acid(Interstate is one) or AGM type.