These batteries are made up of several lead plates in a sulphuric acid solution. The plate is made up of a lead alloy grid with an oxide paste embedded on the grid.

The sulphuric acid and water solution is called electrolyte. The material of the grid is an alloy of lead, as pure lead is a physically weak material and it could break during transport and battery service. Usually, it is a lead alloy with 2-6% of Antimony. The lower the contents of Antimony is, the less resistant will the battery be during the loading process. Less quantity of antimony reduces the production of Hydrogen and Oxygen during charge and therefore, the consumption of water.

On the other hand, a higher proportion of Antimony allows for higher discharges without the plates suffering any damage, which implies a longer battery life. These Lead-Antimony batteries are the “deep cycle” type.

Cadmium and the strontium are used instead of Antimony in order to strengthen the grid. They offer the same advantages and disadvantages as Antimony, but besides, they reduce the self-discharge percentage that the battery suffers when not in use.

Calcium also strengthens the grid and reduces self-discharge. However, calcium reduces the depth of the recommended discharge in no more than 25%. On the other hand, the Lead-Calcium batteries are the “Shallow cycle” type. The negative and positive plates are immersed in a sulphuric acid solution and are subjected to a charge of "formation" by the manufacturer. The direction of this charge turns the paste on the grids of the positive plates into Lead dioxide.

The paste in the negative plates is transformed into spongy Lead. Both materials are highly porous allowing the sulphuric acid solution to enter freely into the plates. The plates alternating in the battery with spacers between them are made of a porous material that allows the electrolyte to flow. They are electrically non-conductors. They may be mixtures of silicone and plastic or rubber. The spacers may be individual sheets or “pouches”. The pouches are sleeves open on the top and are placed only on the positive plates.

A group of positive and negative plates with spacers constitute an "element". An element in a container immersed in an electrolyte constitutes a battery "cell". Larger plates or a greater number of them mean a higher amount of Amps per hour that the battery can supply. Regardless the size of the plates, a cell will supply just a 2 volts nominal current (for Lead-acid).

A battery is made up by several cells or elements connected in series, inside or outside, in order to increase the voltage to normal values for the electrical applications. This is why, a 6 V battery is made up by three cells and one of 6 12 V. The positive plates on one side, and the negative on the other, are interlinked by means of external terminals on the top of the battery.