BoatHowTo · video

What this video covers

Installing a high-output alternator on a small diesel engine can prevent the engine from reaching its rated wide-open throttle RPM.0:31 A 30-horsepower engine typically delivers 25 to 27 horsepower at the transmission, and a high-output alternator can impose a load of 5 to 10 horsepower when the battery bank is deeply discharged.1:19 This parasitic load prevents the engine from achieving full RPM when the alternator operates at maximum capacity.1:46 When the batteries are well-charged, the alternator output drops, allowing the engine to reach its rated RPM.1:52 Modern external voltage regulators, such as the Wakespeed, the Arco Zeus, and the Revitech Altium, solve this by monitoring engine speed and automatically ramping down alternator output as the engine approaches wide-open throttle.2:45 Running an engine under a higher load at lower RPMs can improve overall engine efficiency.2:55 Using an alternator controller to manage load prevents engine strain while maintaining efficient battery charging.2:05

More from BoatHowTo

How to keep you TANK CLEAN in the days of BIODIESEL.. | Ask The Expert with NIGEL CALDERAug 2026PARALLELING Conductors for AMPACITY - is that SAFE?? | Ask The Expert with NIGEL CALDERAug 2026ENGINE OIL turns BLACK right after Oil Change?? | Ask The Expert with NIGEL CALDERAug 2026Same LAYUP RECOMMENDATIONS for FAME and HVO bio diesel? | Ask The Expert with NIGEL CALDERAug 2026

From BoatHowTo — see the channel’s boat, crew, and every analyzed video.

The Sailing Directory Newsletter

One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.