the boat electrical system





Electrical Systems:
We have 2 electrical systems on board. If we are plugged into "shore power" at a dock, we can use AC power (110 voltage) and we have the "normal" household outlets. If we are anchored out, or sailing on a passage, we use a DC electrical system run off of batteries. In New Zealand we added a "transformer" with a direct external dock connection, so now we can plug into any world-wide 220 voltage unit and "transform" the energy to our boat's needed 110 voltage. Our Heart Freedom inverter/charger works great with this transformer and we love being able to plug in anywhere now if we have the option in a marina. A great addition!

Batteries:
Our battery bank consists of 3 (183AmpHour)4D Gel-Cel batteries, for a total of 550 Amphours total. We cycle this "battery bank" between 50% - 90% full, giving us about 220Amphours total to use. The battery bank is monitored by a Tri-metric battery monitor. We also have one dedicated starting battery, separate from the "house bank", so we can always start our engine.

We charge our batteries 3 different ways. When on shore power, our Heart Freedom ininverter/charger charges our battery bank. When using our engine, our alternator on the engine charges the batteries. When sailing or at an anchorage, we use a wind generator and/or solar panels to charge the batteries.

Alternator:
The reality of cruising without a generator is that we need run our engine 1-3 hours a day to charge our house battery bank. We love our wind generator and panels, but, as most of us know, in anchorages it is not always windy or sunny.

Unfortunately, we have had many issues with our alternator charging system. This is pretty typical of the cruising sailor. There aren't too many of us out here world cruising who haven't had to deal with problem solving and fixing their chargning system from time to time. Our problems started in Palau, Micronesia, after 2 1/2 years of cruising. By this time we had fried 3 alternators. One of the alternators was an old Balmar 94-series 120 amp? or so, that came with the boat. This one actually caught on fire in Palau. After disecting it, it looked like the felt washer that insulates between the positive terminal and grounding case wore out over time and the postivive and gound short circuited. Gone. Thankfully we put out the fire with little damage.

Then there were two other Balmar 7-series alternators that fried because of overheating. From what I've learned about these small case alternators (like Balmar's), is that they're really not made for full-time cruising applications. They get too hot. The large case alternators are made for this reality, but for most of us on small boats where space is an issue, we only have room for the small-case alternators. So, if you are like us....what to do about it??

Here's what I've done:

1. We use a Balmar Max Charge MC-612 regulator. We have added both the alternator temperature sensor (MOST IMPORTANT!) as well as the battery temperature sensor. Both of these pieces will make sure you do not "OVERHEAT" either your alternator or you batteries.

2. Use the advance programming mode on the regulator to optimize your situation. If you are having overheating problems, then adjust the AP (Amp Manager) program to tune down the output of the alternator. We sometimes run at only 90% of output. You could go as low as 80% output if you are really having problems. Best to decrease a little at a time and experiment (with the alternator temperature sensor hooked up, of course) depending on your system.

3. Lastly, I have changed some of the charging wiring. Now we have the alternator positive wire going directly to a 120 amp isolator diode. From the diode one positive wire runs to the engine battery and one to the house battery bank. The reasons for this are two-fold. The diode prohibits energy running "backward" to the alternator to eliminate the potential of a possilbe problem. Plus, the diode splits the charge and both the house and starting batteries get charged without needing to use a battery selector switch. The only down side is that the diode takes a little bit of energy, but in our case, this has been a really good change for us.

4. One last wiring change I did is to run a wire direct from the engine battery to the starter. So, the engine is always getting its juice from the starter battery. As a back-up option, I do have a battery selector switch that where both batteries can be "coupled" if the engine needs more energy to start or if there is a problem with the engine starting battery. With this new wiring scheme, however, I have yet to change the battery selector switch.



Renewable Energy System:

Solar:
We have 2 Sharp 80 watt solar panels. They live off the cockpit side rails, and have been designed to swivel up or down so we can point them towards the sun. We have a Blue Sky solar boost 2000e charge controller to regulate the charge to our battery bank. These help a bit, but really not too effective as the sun is usually only shining on one panel at a time and the output is pretty low. Still, better then nothing.

Wind:
We also have a KISS wind generator on a pole off the stern. I chose the KISS because it is simple, solidly-built, quiet, and puts out the juice when there is at least 7-8 knots of wind. At 10 knots of wind, it will put out about 2 amps of power, but power output will dramatically increase with wind speed. It puts out around 9 amps in 15 knots of wind, and 18 amps in 20 knots of wind. All wind generators are a compromise, but this one seems to have the most bang for the buck with amount of power produced, plus the lack of noise it creates. At one point we had the KISS through a charge controller, but after one incident in Mexico where our Trace C-40 malfunctioned and started pulling 30+ amps OUT of the battery bank and putting the energy into the dummy load, I disconnected it. Since then I have the KISS positively wired directly to the battery bank (through a fuse, of course). There is also a shut off switch so you can shut down the wind gen anytime you want to, but overall the KISS is just constantly trickling energy into the house bank. It is very very very unlikely that we would overcharge our battery bank with the wind gen because we are "cruising" and our batteries are almost never charged up completely. After 3+ years of cruising on DK, we still think the KISS is the best wind generator you can get for a small sailboat and we really love ours!