Alternator Upgrade

Feb 2013. The decision to refit with a new engine has given the opportunity to look at the engine charging regime. Yanmar do a standard 80 Amp alternator but with the amount of systems on the boat and size of the battery bank an alternator upgrade will be inevitable. Yanmar do a second alternator kit but it sticks out of the starboard side a long way so will not be practical. When faced with a problem, enquiries on the forums usually always turns up trumps and on this occasion it was true to form. I was put in contact with Elextromaax who have a very helpful website and are specialist in aftermarket charging systems. The problem with larger capacity alternators is two fold. Firstly they put undue strain on the pulleys and belts and secondly they tend to be inefficient at low revs. Electromaax have a total solution off the shelf which comprises a range of alternators from 80 to 180 amps, smart charging regulators and the Pièce de résistance, the Serpentine Pulley Kit. This kit replaces the existing pulleys to provide an industrial 10 grove segment belt. This has significant advantages over the normal V Belt as it does not wear the same, avoiding dust, grips better and distributes the load around the pulley putting less strain on the bearings. I was initially worried about replacing parts of the new engine and the result this might have on warranty but a quick telephone call to the local agent reassured me that firstly the system is kinder to the engine and secondly the system is designed in conjunction with Yanmar. The order has been placed and I will document the fitting when the engine arrives in two weeks.
March 2013. The packages arrived very quickly and were delivered to ABC Powermarine to fit with the engine. There was a moment of panic as we couldn't find the package for the automatic belt tensioner. It turns out it was smaller than we thought and was in the small pulley box. Ron the engineer was keen to install the engine with the original equipment and retro fit the Serpentine system. Although this might make the later fitting slightly more difficult it would a least prove the new engine with Original Equipment.
Apr 2013. The Install. The engine has been fitted and today was the start up day. Everything was prepared and it was decided to start her up with the original alternator fitted. Much to my surprise but not to Rons, the engine fired up first time and ran like a dream. After shutdown it was time to break out the Electromaax Serpentine system and larger alternator. The instructions were relatively simple and to be honest the install was fairly intuitive. There are detailed photographs and commentary here. The only thing we did get wrong was fitting the plate for the belt tensioner before the belt. Should have followed the instruction more closely! The most surprising thing was it only took 2 hours from start to finnish to do the install and that included a tea break. Over the next few weeks I will report on its use and the performance of the charging.