Battery Doctors treat the biggest cause of battery problems which is sulphation. This accounts for vast majority of 12V automotive batteries being discarded when actually this is a needless waste.

Sulphation is a naturally occurring process. It is simply crystals of lead sulphate that build up on the lead plates. These crystals can harden to form a barrier that will prevent the battery ever being fully charged leading to worsening performance until eventually the vehicle will not start.

Undercharging the battery ie Short journeys, occasional use, will also cause sulphation problems and degrading of the batteries performance. Although sulphation occurs more rapidly under hotter temperatures, it often only comes to light in the winter when the oil in the vehicle is thicker and puts a greater load on the battery.

Other causes of battery failure are more physical such as shorted cells, cracked cases, overcharging etc.