12 volts system, what a novel and easy system for gunk huller, on blue water sailing. Well so is the misunderstanding. It is not an easy system, (mind you it can be deciphered with proper research) And after 40 years of playing with boats, I am just starting to understand it all, or so I think. Who’s fault is it ? the answer is in two parts, first the sailor him/herself, for not researching, but also the internet. The internet is a beautiful thing, so much information’s out there. The problem is, also so much dis-information’s, Wanna be teachers, wanna look good kind of people, or just too much time on their hands and not enough brains to go with it. The second part of the problems, which in my opinion is where 95% of the problem arises from. Are the sales peoples. They do not know their products, they do not care, all they want is their commissions. No matter what lies they have to tell you in order to convince you to by their products. In My 40 years of toying with boats, I finally found out a real knowledgeable sales person. Where, In a small town in Quebec about a 1 1/2 hour drive north of Montreal. He knew exactly what I was talking about, knew the specs by heart, knew what system to go with what other system, proposed a similar product at a cheaper price, and compared the two of them with no hold bars, just plain truth.
This is going to be a very long blog, and it will have to be done in many steps. I am still on the water after all. First the biggest problem of having the proper stuff to live on a 12 volts system is cost. Especially if you are in the middle of no where, and replace your house battery bank. It is not like in the U.S. or Canada, where prices are fairly competitive because of so many sales persons trying you sell you their products, especially if you are talking about 4 or 6 batteries at a time. You can hear the chiching sound as they salivate over their commission. Never mind the lead acid batteries, their first option will be to push on you is AGM versus acid filled. (Of course we are talking deep-cycles here since we are talking house bank) Are AGM better then acid. most people would say yes, Where My problem lies, is cost versus return on your money. A good acid battery, well care for, well maintained and not abused should last you an average 5 years, depending on the brand, cheaper batteries,( I mean manufacturer here) last less then good batteries. AGM will last longer, possibly 7 years or so. Again, as long as they are cared for properly, monitored, and not abused. Abused batteries die fast and cost a fortune. I know I have done it in the past, learned My lesson, bit the bullet and moved one. If you make a mistake once, it is called learning, twice, it is call stupidity. so an AGM will last 2 to 3 years longer then acid batteries. So it is a 30 to 40% more life. The problem is, good AGM cost 50 to 70% more then acids. You do the maths, and see if it is worth it to you. In My opinion, it is not worth it for Me until the price comes down. Then perhaps I will switch to AGM. An other factor, the weight. AGM weight way more then acids batteries, and are harder to get in countries like Guatemala, Honduras etc… If you are a North American cruiser, no problem, if you are a blue water sailor like Me, Huge problem, with the weight, comes the increase cost of shipping, some times as much as $200.00 per units, more if it an 8D. Then there is customs, taxes, unless you can declare in “transit” and some countries do not care if you are in transit or not. you have money, they want it. After all even with My miserable pension, I still can make more then a 100 times more then the locals. In Canada I am a poor schmuck, here I am a rich gringo. But a battery that sell for $180.00 in the U.S. sells for about $240.00 here. Acid ones that is. You see where I am going with this. So research, research, research.
Next is the capacity. Battery salesmen are notorious to over state the capacities of batteries. A battery that was sold at a capacity rating of 450 Amp hours, will typically produce 400 Aph/hrs, so it is better to over size your batteries, then kill them in the first year. Next come the charging systems. It can be easy if you are a day sailor, go for a joy ride once in a while, then charge them back on shore power for a month or so, until the next joy ride. Me, I need a more serious system then that. I need solar panels, wind generator, Fuel generator, motor alternator etc…. Why ? Because I have a fridge that is a pig on power, then the water maker ( We wont go there). Electronics instrumentation’s, because no one uses sextant anymore. I need to cook, vacuum, use lights, water pumps, water heater etc…. etc… etc…. Now it gets complicated. Because of the charging systems you will need, you will also need multiple charging systems, and to use those you will need a charge controller, and if you are smart, you will invest in a good charge monitor. The controller, well that one is easy to understand. You will need a device that will neither fry your batteries, nor let them die prematurely. Now why the monitor. Well if there is something wrong with your system, you will not know it until it is too late. Batteries are all ready fried, or drained past survival state. No CPR, no mouth to mouth, a dead battery is a dead battery. And just a side note here. forget all that stuff about reviving batteries on the internet. I have been toying with it for the last 40 years, no Epsom salt, no washing with baking powder. It DOES NOT WORK. Dead is dead, end of the conversation. If you are a land lubber, go ahead play with it. if you are in the blue yonder, and come into a storm, and cannot start your engine for emergency, or need power to get in between two close reef, you well quickly understand what I mean by dead is dead. And unfortunately, that might be you, So do you really want to risk it ????????
An other component to consider, is wiring. Very, very important, too small, and you have over heating, possible fire situation, lack of conductivity. Too big, loss of currant, more expenses etc…. So My 2 cents is go with the proper wiring size, and add 5 to 10% in size. Do not cheap out on the wiring. You will be asking for trouble. There are many professional sites on the internet that will do the calculations for you. Voltage, amperage and distance, usually is what you need to know.
Ok now lets look at every thing separately. First the batteries. once you decide your preference, acid versus AGM according of your budget, the size and amount of amp hours. The problem with size on boats, is usually the battery locations. Remember, batteries needs to be in a proper battery tray, with good ventilation. Otherwise you could have a disaster on your hands. In My lifetime, I have seen boats literally blow out of the water, or having acid eating through structures. Unfortunately for My boat, the battery well, dictate My size of batteries, which are golf cart batteries 6 volts. Not a bad thing, since after some research, I learned that 4 X 6 volts, two in series, and two in parallel, gives you twice the amperage rating, at twice the voltage. Thus a 225 amp 6 volts time two on both figures will give you 450 amp hours at 12 volts. That is for My at this time very border line from what I need. Because My fridge is a pig on power. 6.5 amp hour. I am shopping for a new one, with half the consumption, then I will be styling. until then, I have to be very careful with battery consumption. LED lights can also cut on consumption’s, 1.5 amp hour versus .03 amp hours, makes a huge difference. especially if you are careless and think your boat should be lit up like a Christmas tree. Some people use inverses to run A/C even at anchor. I find that ridiculous, but lets face it we all have our zone of needs and comfort. so if you think that for instance a fridge uses 6.5 amp hours, and runs half of the time, then that is 78 amp in a day. now you will use water pump, bilge pump lights at night etc…. etc… etc…. It does add up. so lets say you use 95 amp hours in a day, and your batteries are 450 amp hours, that means you are using 21% not bad, but battery manufacturer are notorious for over rating their batteries. After all it looks good on paper. I found out that My 450 amp/h batteries actually hold only 400 amp/h so now you are at 23%. give an average loss of 2% over the wires, now we are at 25% and it keeps adding up like that. on and on and on. So do yourself a favor, oversize your batteries. because once you start using your electronics, like Auto-pilots (energy pig) chart plotter (energy pig), other instruments like VHF, wind instruments, depth sender, are you getting the picture yet ??????? it all add up. Sure you can run your engine all the time, find if you have a yacht, but why buy a sailboat if your need to be motoring all the time. And the problem with batteries, is if you let them drain too much, they will never, and I mean never, get back to their original states. So now you have to deal not with 400 amp/h which was the original state of the batteries, but more like 300 amp/h. now you are in trouble.So try to over size your amp/h as much as possible (to a point. because there can also be over doing it) Use good judgement.
So 100% battery reliance impossible. That is why we use alternators, wind generators, solar panels, gas or diesel generators, chargers, etc…..If you have those you need also charge controller, voltage regulator, a battery monitor is also not a bad idea. In my opinion, a good monitor is a must, it will do nothing per say for your batteries, but it will help you understand what is happening to your batteries before it is too late. Mine is a fairly high end one, it tells me how long since last 100%, when was the batteries last equalized, how much I draw, how much I am charging, it has alarms that warns me before it is too late. etc…
Back it it in a few days.