GMK’s Alternator Sizing Calculator
Enter RMS watts to estimate alternator size. AGM/LTO + daily/demo included.
Find the best-fit Apex alternator range for your setup. Tool by GMK Audio.
60A is a solid default.
Reserve helps on peaks. Alternator handles recovery.
Most amps are Class D
Upgraded charge wire + proper fusing
Main issue is dimming at idle
Planning guide only. Final fitment, voltage, and battery setup still matter.
For a free quote on your custom high output Apex alternator,