Thanks a lot for the information on Deep Discharge Batteries. Also it is said that the batteries have some kind of memory , which means it gets tuned to the charge/discharge pattern which is regularly used. If something out of the regular routine is tried later then the battery does not give optimum performance. e.g if you are doing only partial discharge every day and recharging again to full, then a sudden deep discharge may damage the battery.
Depth of Discharge (DOD) [%] The percentage of battery capacity that has been discharged, expressed as a percentage of maximum capacity. A discharge to at least 80% DOD is referred to as a deep discharge. Manufacturers make adjustments to the size and configuration of electrodes and chemistry, in order that there is less damage to cells when the battery is discharged to this high amount. Marine batteries are often of the deep-discharge type.
This is a nice primer on Batteries. While working on Electrical vehicle project , where I was a novice as far as battery technology is concerned, I was bombarded with many of these terms. One fo the term often used was "Deep Discharge" batteries. Could you elaborate on this ?