Power generation is supplied by a system made by Ample Power and installed by Farallon Electronics in Sausalito. Power is key to keeping all electronic systems operating and Ron Romaine of Farallon really knows what he is doing.
The system has a 115 amp alternator and computer controlled 3 stage regulator. These are connected to a house bank of 6 group 27 80 amp/hr gel cell batteries with a total bank capacity of about 480 amp/hrs giving us an effective capacity of about 240 amp/hrs or 50 % of the total. A 7th battery is isolated as the starter battery.
We wanted to install a large frame alternator capable of generating 180 amp/hr but we didn't have clearance so we invested in halogen lights and Hella fans to reduce our daily consumption. These 2 changes cut the consumption from lights and fans in excess of half and should have our daily usage at about 80 amp/hrs.
2/28/97 Update - Our daily usage is 110 amps a day due to increased fridge runtimes and our alternator burned its field coil wires causing an intermittent ground fault that would put the regulator into an error condition. It took a long time to figure out what the problem was. Even though the alternator was new we decided to pay to have it repaired in La Paz. It is very difficult to ship equipment in and out of Mexico and you either get hit with large customs bills or worse, have the equipment disappear so we had it rewired in La Paz for $42 USD. It has worked flawlessly for 9 months without dock power so we don't regret our decision.
Our only complaint is that we have to run our engine at very high RPM's to get good output from our system. We would like an additional method of generating power. We could add a small generator to our lazarette but it would be noisy and take up a lot of valuable space. It would also be expensive. We are leaning toward solar panels sufficient to cover about half to 2/3 of our power needs and prolonging our interval between charges to 2 or 3 days. We will look at our options when we get to Australia or New Zealand.