Charging a battery correctly makes all the difference. Yet the impact of charging correctly is often underestimated. In this, choosing the right charger is half the battle. The wrong charger causes direct or indirect damage to the battery, shortening its life span. Pbq has more than 10 years of experience with valve regulated lead-acid batteries. We often see that there is not a good match between the lead-acid battery and the charger. This has a negative impact on battery performance and service life. To choose the right charger for your battery, it is very important to understand the characteristics of an AGM battery.
The characteristics of AGM batteries
The charging current for each battery is limited. For a VRLA battery, the maximum charging current is 0.3CA. This means that the charge current should be a maximum of 0.3 times the capacity of the battery. If this threshold is exceeded, the battery may become hot. In this case, the battery’s internal structure and chemical composition become damaged and the battery permanently loses capacity. The charging voltage is another number to watch out for. Each cell of an AGM battery has a nominal voltage of 2 volts, and a 2-volt AGM battery consists of a series arrangement of 6 cells. Temperature also greatly affects a battery’s performance. The charging voltage must be compensated if the ambient temperature differs from 25 degrees C.
Charging 2-volt batteries
A battery will never become full by charging it at 2 volts per cell. This requires about 2.4 volts per cell. In contrast, electrolysis with water, a component of electrolyte, can charge at 2.3 volts per cell. Therefore, it is very important not to leave the battery charger at a high voltage when the battery is almost full.
Charging gel batteries
Gel batteries have a lower charging voltage than AGM (Absorbing Glass Material) batteries. Batteries used for standby applications have a lower charging voltage than batteries used for cyclic applications. Always refer to the information on the battery’s label and its data sheet.
The charging protocol of batteries
There are many different ways to charge a battery and each type of battery will have a specific charging recommendation. Therefore, it is necessary to choose a special VRLA charger for a VRLA battery. This is because the wrong battery charger can permanently damage the battery. A VRLA battery is charged according to the CC/CV charging protocol. CC/CV stands for the two main phases in the charging process: constant current and constant voltage. After these two phases, the battery recharges with a trickle charge. Each phase has its own specific values and this depends on the battery type, battery capacity and usage.
Which charger should you choose?
A thoughtful choice of battery charger extends the life of your batteries. Read more information about charging in the datasheet of your batteries. You can find suitable chargers in our wide range of battery chargers!
