Open lead-acid batteries are multi-element batteries each consisting of a set of pairs of lead plates for the negative pole and lead oxide plates for the positive pole bathed in a solution of water and sulphuric acid.
During the charging cycles of these lead batteries, the high temperatures generated evaporate some of the electrolyte which endangers the battery (this is why it is always advisable to monitor the temperature of the batteries. Good chargers now often have a temperature sensor to adjust the charging current.) It is therefore essential that the electrolyte is checked and replenished periodically. In addition, the presence of liquid inside prohibits the lying position for these batteries (they are not sealed).
Very good starter batteries
This type of battery has the best capacity/weight efficiency of all lead batteries. Indeed, lead plates are thin and have a large surface area. The main advantage of these batteries is that they can deliver a high current over a short period of time, which is, for example, ideal for operating an internal combustion engine starter motor. On the other hand, the thinness of the lead plates makes them unsuitable for prolonged discharges (their use as service batteries is not recommended).
Setting the 3-phase charger
- Bulk 14.7V
- Absorption 14.7V
- Float 13.6V
Advantages of open lead batteries
- Good space/capacity/weight ratio
- High instantaneous discharge capacity
- Low price
Disadvantages of open lead batteries
- In the case of deep discharges or certain charges that are too fast, the electrolyte starts to boil and releases a toxic gas
- Cannot withstand high temperatures which accelerate the phenomenon of electrolyte debullification
