AGM Battery - Description Of Components
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COMPONENTS OF AGM BATTERY
| Key | Explanation | Key | Explanation |
|---|---|---|---|
| 1 | Positive grid with silver alloy | 2 | Positive plate |
| 3 | Negative grid | 4 | Negative plate |
| 5 | Separator made of glass-fibre fleece | 6 | Set of positive plates |
| 7 | Set of negative plates | 8 | Block of plates |
| 9 | Block case with base strips |
Construction
AGM batteries differ from conventional lead-calcium batteries in the following points:
- Larger plates: Larger plates allow a power density some 25% greater.
- Glass-fibre-fleece separators: This enables a cycle consistency up to 3 times greater to be achieved. This improves cold-starting ability, current consumption and service life.
- Airtight housing with pressure relief valve (please refer to "How it works"): The inspection plugs are sealed and cannot be opened.
- Acid bound in grass-fibre fleece: The acid is not held freely in the housing, as is the case with other tires of batteries, but rather it is completely bound (100%) in the glass-fibre fleece. This gives increased security against the acid escaping and thus reduces the environmental risk.
How it works
AGM batteries differ from conventional lead-calcium batteries in their environmentally compatibility and their retention of substance during charging.
When a vehicle battery is charged, the electrolysis process emits the gases oxygen and hydrogen.
- In a conventional lead-calcium battery, these two gases are released into the atmosphere.
- In an AGM battery, the two gases are converted back into water: The oxygen discharged at the positive electrode during recharging "wanders" through the fiberglass fleece to the negative electrode. At the negative electrode, the oxygen reacts with the hydrogen ions in the electrolyte to form water (oxygen cycle).
In this manner, the gas, and thus the electrolyte, is not lost.
The pressure relief valve will only let off gas if too much pressure builds up (20 to 200 mbar). When this happens, the pressure relief valve will not allow atmospheric oxygen to enter. Because the pressure in the battery is regulated by a valve, the AGM battery is also known as the VRLA battery (valve-regulated lead acid).