I ncreasi ng Generator Loads

Batteries as a buffer play a critical role in raising average generator loads. The basic concept is to put as many DC-to-AC inverters on the boat as are necessary to run the boat’s AC systems, together with a battery bank large enough to run the inverters, and to then only run the generator if the combined AC loads and battery charge-acceptance rate keep the generator pegged at its ideal operating point (sweet spot). Any time the load falls off, the generator is shut down and the AC system is run off the inverters. Once the batteries are discharged to the point that the combined AC load and battery-charging load will optimally load the generator, the generator is restarted. The process can be fully automated and seamless.

Although there is no problem “stacking” multiple inverters to get just about any desired AC capacity, in practice for high AC loads the battery requirements make this unrealistic: Some modification of the scenario described is frequently called for. At the most basic level, major AC appliances can be given a “soft start,” eliminating the high inrush loads of older appliances and as such taking the peaks off the AC system. This also substantially reduces the maxi-

Want to learn more about your boat’s electrical system or perhaps you’d like to pick Nigel Calder’s brain further about electrical efficiency? You can catch up with him in person at one of the below events. Tell him Power&Motoryacht sent you!

Southwest International Boat Show ( southwestint ernationalboatshow.com): March 17th and 18th.

Trawlerfest Anacortes ( www.passagemaker.com): May 17th and 18th.

Seattle Boat Show ( www.seattleboatshow.com): February 4th and 6th.