Alternator Calculator
Calculate the alternator size needed for your vehicle’s electrical system. Understand how power requirements, accessories, and battery type affect alternator sizing.
Step 1: Electrical System Details
Understanding Alternator Sizing
The alternator must supply enough current to power all electrical accessories while also recharging the battery. Undersized alternators can lead to battery drain and electrical issues.
Step 2: Electrical Load
About Electrical Load
The base load includes essential systems like ignition, fuel pump, and ECU. Additional accessories increase the total electrical demand. A safety margin ensures the alternator can handle unexpected loads and maintains battery charging.
Alternator Sizing Results
Recommended Alternator Size
Alternator Size Comparison
| Vehicle Type | Typical Load | Standard Alternator | Recommended | High-Performance |
|---|
Electrical Load Breakdown
Alternator Sizing Formula
Alternator Size = (Base Load + Accessory Load) × (1 + Safety Margin)
The alternator must supply enough current to power all electrical accessories while also providing 10-30% of its capacity for battery charging. Higher safety margins are recommended for vehicles with frequent short trips or extreme climate conditions.
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