Sabtu, 07 Februari 2009

Batteries and Battery Chargers For The Boat

The charging system on Beach House is coming along and is a major improvement from what we started with. It is also a bit unconventional for a boat charging system. After many years of installing these systems on my own and other boats I am always looking for a better and simpler way. The trend on boats today is to move away from simple into the complex as manufacturers try to integrate more systems and get single pieces of equipment to do more. The results have been more breakdowns and fewer repairs that can be done by owners. More capabilities and information are at your fingertips, but at a cost. In the last year, I have heard more and more reports about the Iota battery chargers and their use on boats. These units are not just chargers but converters as well. This means that the 12 volt system on the boat can be run off these units even if a battery were not connected. Not all marine battery chargers can do this and some can be damaged trying. The units convert the 120 volt AC to 13.6 volts nominal DC. The units are called "smart chargers" because they will deliver maximum current for whatever period of time needed to replace the charge but not stress the batteries. It will cut back to virtually milliamps once full charging has been achieved while still maintaining the proper voltage and will maintain that voltage under whatever demands are placed on it. The units are completely silent and do not run hot like many other chargers. They also use what Iota calls Tight Line Regulation which insures that the output voltage stays steady from no load to full load. This will keeps onboard pumps, lights, and motors operating at the correct voltage and thereby increasing their life. An equalization charge on the batteries on a regular basis goes a long way to prolonging the batteries life. The Iota will sense if an equalization charge has not been done for a week and will equalize without overcharging and gassing the water out of the batteries.



There is one drawback to these units. They are not designed for multiple banks of batteries. For that reason I had put off installing one until I did a bit more research and determine how others have overcome this shortfall. In discussion with other boat owners and the helpful folks at Iota the answer for us was simple. The chargers range from 15 amp up to 90 amp. The solution to our dilemma turned out to be as simple as installing a charger for each battery bank. By installing two chargers, which can be done in series or parallel , you have doubled what a single charger will do. By installing a single 45 amp charger on each bank we can charge them most efficiently and will have a back up in the event one would fail. A bonus is that even with two chargers they are less expensive than most of the "marine" chargers on the market. But we still had one more problem to overcome. With the starting battery we actually have three banks to charge.

Once again the solution was simple with a little research. Many of the expensive charger/inverter units have a built in Echo Charger specifically to charge the start batteries. These Echo Chargers can be bought separately and are perfect, in my opinion for starting batteries. The starting battery really only needs to be charged for a short time after the engine is started. The alternator usually does a quick job of this and after that a maintenance charge is all that is needed. A dedicated charger for the start battery would seem to be a waste of energy. The Echo charger can be connected to the starting battery via the house bank and the chargers can maintain any amps removed from the house bank by the Echo Charger to maintain the starting battery. This can allow all charging systems, the battery charger and the alternator, to be connected to the house bank where charging is needed the most. For the time being the alternator is connected to the battery switch which allows us to choose either bank or both to be charged off of the alternator. I am not happy with this set up since I would prefer to have the alternator connected to the house banks so perhaps a relay will solve that part, but that has not been done yet.

This set up may not work for every situation but we have found it perfect for our current charging needs. The house bank consists of two sets of two 6 volt deep cycles at 220 amp hours each for a total of 440 amp hours. These are equivalent to two 8D's which would cost four times as much and weigh four times as much. In the past we have averaged about 6 to 7 years for each pair with this set up and 8D's over the years have not given us better service. The start battery is a single heavy duty truck battery for cranking. When we are cruising our power demands are rather high so an efficient and simple charging system is important to us.

Minggu, 01 Februari 2009

Another Update

The teak master continues making the exterior wood look beautiful as systems continue on the to-do list. The teak work seems never ending and overwhelming sometimes, but with each section that gets done the boat looks better and better. We tried to convince ourselves that when we bought the next boat after our sailboat was sold that we would buy one with no teak on the outside. So what we did was buy one with even more teak than the sailboat had and not in very good shape. The weather this time of year also slows the process and we are expecting a couple of days of rain so the going will be slow. In addition to the refinishing, we have to be careful to not leave holes from the hardware for the rain to leak in. But since we have been doing this for many years we have it down to a science. The holes from the hardware are caulked to keep water out but not so that the hardware can't be re-bedded when it goes back on. With the Sikkens Cetol we use there is no need to sand between each coat, which helps a lot, and the coat that went on in the morning is dry enough by afternoon so that if it rains, it won't hurt the finish. The usual approach is three coats of the base, we now use the "natural teak" coating, and three coats of the gloss. With the new natural color, it does not change the color of the teak and give it that brown or orange coloring as the older bases did. Once the gloss goes on, it is difficult to tell from the usual types of varnish. After these six coats, all that is needed is a yearly maintenance coat afterwards. That is why we switched from traditional varnish several years ago.



The interior is not getting neglected. Some new faucets to replace the originals give the galley a more modern look. Replacing the galley faucet required the spacers between the drawers to be removed to get access and after the faucet was replaced the spacers had to be epoxied back in place. Underway latches have been added to doors to keep them from opening and spilling their contents in a seaway when the conditions get boisterous. And the controls and power for the satellite dish are now in the main cabin so there is no need to go up in the flybridge to make fine tune adjustments.

We finally have a complete house bank of batteries. A second set of 6 volt golf cart wet cells have been added and we now have a total of about 440 amp hours on the bank. The decision as to whether we will add an additional bank will be made after we have a chance to cruise her a bit and see what our requirements will be. With the sailboat we spent lot of time underway with electronics and equipment running without the engine charging. With the trawler we will be running the engine much more and the batteries will get plenty of charge. So we will need some time at anchor to determine if more battery power is warranted. An additional charger will be installed as soon as it arrives so each house bank will now have its own charger which will be 45 amps each for a total of 90 amps for the house bank. The Xantrex echo charger is doing a great job of keeping the starting battery charged from the house bank and the house bank is charged by the Iota chargers from shore power and the alternator under way. We are very pleased with this set up at this point and still have some old wiring to replace. The project list is coming along nicely albeit slower than we would like. But that is just the nature of the beast. we will continue to post updates as we complete them.