The weather has been pretty good and, by now, you and your boat should have a few cruising days under your life-jacket. The major projects are finished, or on hold, and now is the time for relaxing and enjoying the scenery. This month we are going to take a look at some of the calls we receive during the summer cruising months.
Why is my inverter buzzing and can it overheat?
There are two types of inverters, true sine wave and modified sine wave. Modified sine wave are noisier, less expensive and run some, but not all AC appliances properly. True sine wave are more expensive, will run all AC appliances such as microwaves, blenders and flat-screen displays but are quieter and are more efficient.
Both inverters will make a buzzing noise, this is normal and a function of the load. Unfortunately, many inverters are installed in a small space with little air movement and can get quite hot. Most inverters will have an automatic shut-off which will prevent it from over-heating. If your inverter is in a cabinet, it is a good idea to leave the door open while you are using it, or better still provide good venting.
This is worth repeating: When you are not using your inverter, turn it off.
During the day when you are off in the dinghy or during the night while you sleep, you may not need to run your inverter. Just turn it on when you are making coffee, watching the TV or using another 110-volt appliance. When the inverter is on and nothing is plugged in (no load), the unit itself can still use between one and three amps per hour. 12 amp-hours to 36 amp-hours per day is a long time to sit idling.
If all you want to do is charge your cell phone or iPad, simply use a cigarette-style USB adaptor. It works directly off 12 volts and you spare the energy loss of converting DC to AC and back to DC again. They are inexpensive and are available online or at electronic stores. The only gotcha here is to make sure the USB adaptor has the wattage to handle the power required to re-charge a tablet.
In the warmer weather, should I be concerned about my batteries overheating?
When you are using your boat more often, and especially when you are cycling the batteries, you should check the water level in your flooded deep-cycle batteries more frequently than in the off season. You should not need to add distilled water more than once a month and you should never allow the water level to go below the plates. Using a battery temperature sensor to monitor changes in battery temperature will provide information to your inverter/charger so it can adjust the voltage, this will optimize charging and extend your battery life.’
My battery monitor stopped reading the batteries, what should I do?
The first thing to do is check your battery monitor voltage sensor and power connections at your battery, perhaps the fuse has blown in either connection. Next, get yourself a good multimeter, they are inexpensive and available at places like Lordco. Use the meter to measure that voltage at the batteries, at rest the batteries should be between 11VDC to 12.8VDC. If you have a voltage at the battery and none at the battery monitor, you know the problem lies in between the battery monitor and battery.
We highly recommend that you put together a complete set of both glass and blade fuses. Spend the time to go over your boat and make a list of the fuses you are using. They are readily available at your local chandler. Quite often we zap strap or tape an extra fuse in the location of the actual fuse so you don’t have to go hunting for them. It’s much easier to pick up fuses in Vancouver than anchored at the end of Princess Louisa.
My generator is not charging the batteries as fast I thought it would
First thing to check if you have a manual AC source selector switch is that you switched it from “off” or “shore” to “generator.” Second, while using the generator the batteries are charged through the charger, so look at the voltage on your batteries before and after you run your generator. Normally, you should see a voltage above 13 VDC once the generator is running the charger.
Here is a gotcha: don’t always look for a charging voltage of 13 VDC. If your batteries are heavily depleted, the voltage before running the generator might be 11.5 VDC. Once the generator starts the voltage might only rise to 12.5 VDC at the beginning of the charge. The trick here is to look for an increase in battery voltage. If there is no difference before and after running the generator then you know the charger is not functioning off the generator. Having too little charging capacity is common problem these days.
Many boaters add and add battery capacity, but they rarely consider matching their battery capacity to their charging capabilities. As a rule of thumb, you should have a minimum of 10 to 20 percent of charging capacity compared to your battery bank size. We often are tasked with changing chargers for this purpose or even adding a second or third charger to properly charge a large battery bank and also to reduce genset runtime.
I was anchored for two days and then ran the boat for three hours to my next destination but my batteries were not charged, how do I know if my alternator is charging my house and starter batteries?
First thing is to look at is voltage on the engine gauge, which should show an increase of volts after the engine started. Assuming the batteries are not too discharged, you should see a voltage of 13.5 or higher. As with sizing the charger for your batteries, it’s also important to match the alternator to your battery bank size. We see many boaters whose alternators barely keep up with the loads while onboard. In some cases the loads on the batteries exceed the charging capacity of the alternators. Over time the batteries will drain even if the motors are running.
Check your anchor winch or windlass
We recently had a client call us because her normally reliable windlass on her older 34-foot Bayliner was sporadically blowing the fuse. The wires and connections were all good so it was isolated to the windlass itself. These symptoms are typical of a windlass motor in need of attention. After removing the windlass, it was easy to see that the motor had completely corroded from years of exposure to salt air. Most anchor winches are installed in a housing on the bow which is not properly sealed. It is a good idea to take if off and inspect it prior to the start of every boating season.
Check your bilge pump
One last thing we see quite often is a bilge pump that has stopped working. Throughout the summer season, make sure to check both the automatic switch and the manual operation by simply lifting the float switch and the remote manual switch. It is always a good idea to have a spare float switch and bilge pump on board.
About the author: Jeff Cote is a systems design engineer and owner of Pacific Yacht Systems, a full service shop delivering marine electrical and navigation solutions for recreational boats. Visit their website and blog for info and articles on marine electrical systems, projects and more: www.pysystems.ca.