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Shown here is the engine compartment installation location |
G1 | On-board electrical system battery |
Location
Depending on the vehicle model and equipment involved, the on-board electrical system battery is located either in the engine compartment or in the vehicle interior.
Task
The on-board electrical system battery is used to store electrical energy and make it available, if necessary. It also supplies all other electrical consumers in the vehicle with electrical energy. When driving, the on-board electrical system battery is charged by an alternator or by an energy transfer from the 48 V on-board electrical system (vehicles with 48-V technology) or a high-voltage on-board electrical system (hybrid vehicles).
Design types
A differentiation is made between the following design types for the on-board electrical system battery:
Wet batteries
Lead batteries are wet batteries; the electrolyte is liquid and usually bound in distilled water. Gas forms in these batteries that escapes in open-air models. As the water vaporizes, the fill level must be checked regularly. The currently customary lead batteries however, almost always have a closed housing with a pressure relief valve, and they are therefore maintenance free.
Fleece batteries
Fleece batteries are a subclass of (closed) lead batteries. With the fleece battery, the electrolyte is absorbed by capillary action in a fiberglass fleece (AGM means Absorbent Glass Mat). In contrast to conventional on-board electrical system batteries, the fleece battery does not contain any liquid. In the event of an accident this can increase the level of safety involved. The thermal sensitivity of the fleece batteries means that they are seldom installed in the engine compartment. The fleece battery has good cold-start properties, has a low sensitivity to deep discharging, is extremely vibration-resistant and it can be stored in any position.
Lithium-ion batteries
The high energy density, low weight and space requirement (depending on the battery capacity) of lithium-ion batteries means that they are suitable, e.g. for use as high-voltage batteries in hybrid vehicles.