Battery Bank

[TritonSailor]

I'm trying to sift through all the priorities in my head and what I have the money upfront to do, of course I almost forgot about power. I pretty thoroughly researched what kind of power I'll be sucking up and it comes up to about 400-600 AH a day. I was trying to be overly realistic with this sum, better more than too little. I have heard good things about the Trojan T-105, but I also heard of it's safety issues in salt water. Anybody have ideas for a 400-600 ah house bank that will be supplemented by solar and wind...and may a little engine...

Thanks

Jeff

[Capn_Tom]

'll be sucking up and it comes up to about 400-600 AH a day.

Is this your planned usage? It seems very high. You'll want you battery bank to have sufficient capacity to be at least twice your usage between charges. In other words if your daily use is 200 AH and you plan to charge daily you will need a minimum of a 400 AH bank. If you want to go 48 hours between charges you'll need at least 800 AH.

4 T-105's will give you a 450 AH bank at 12 volts.

[David]

My feeling about your battery question that you should first decide how much stroage space you wish to devote to batteries and let that govern your amperage budget.

[TritonSailor]

My short term plan is to refit to liveaboard and then refit for singlehand long range cruising e.g transpacifc via Panama Canal. I still don't have the how many batteries gives me the what AH, but I have figured my ballpark daily usage, taking into account navigation electronics, ssb, vhf, laptop, nav lights, autopilot and whatever else. I think 400AH+ is a ballpark figure? Right? Capn_Tom, I thought T-105 were rated at 225AH, why does it take 4 to get me 450AH? Is the T-105 ok for marine use , with the sulfuric acid and salt water mix, as well as it being prone to damage when the boat heels over from the acid tipping and exposing the plates.

Thanks

Jeff

[David]

If you are looking for 400 ah you would be better off with 4 group 31 gel or AGM batteries than the 6v 105's.

[Rachel]

That almost seems unrealistic for daily usage on a Triton. Not that you couldn't make it work, but it starts to say "I need a bigger boat for all these batteries and solar panels and a generator."

When I lived aboard and cruised on a couple of boats in the 12,000 - 25,000 lb. range (30' and 32" respectively), here's what we had:

Boat one had, if I remember correctly, about 200ah of house bank. It was all we could reasonably fit. We had mostly manual stuff, and used oil lamps for cabin lighting (had electrics, but only used them supplementarily). We did have an SSB, RADAR, and a laptop, but used them sparingly. For charging we had a medium-sized solar panel, a low-output wind generator, and the engine alternator (used sparingly). We had no refrigeration, no wired in inverter, and mostly used the windvane for steerage. We did have electric nav lights, and this was before LEDs were practical.

On boat two, we managed to cram in 360ah of house bank (with a tape measure and a shoe horn). We had similar equipment to boat one, except we used electric lights more, some autopilot, and lots of laptoppage. There was a hard-wired inverter, which we used occasionally in short bursts (mini vacuum, drill battery charging, etc.)_We had a large solar panel and the engine alternator for charging (again used sparingly, although more than we probably should have due to not having enough charging capacity (needed more solar panels, a wind generator, or less laptop usage ;) LED or cold cathode lighting would have helped a lot, as we both did a lot of reading by electric light). Even on this boat I know we didn't come near to using 400ah per day. If we had, we would have been running the engine like mad to re-charge our batteries.

I'm curious how you're coming up with the 400ah.

Edited to add: Note that since the Trojan T-105's are 6 volt, you have to have two of them to make a 12volt cell. So you have to "halve" the amp hours of each one. In other words, it takes two 225ah T-105's to give you 225ah.

[Hirilondë]

I think I might have used 400 - 600 amp hours on my 11 day vacation this past summer. What are you running that fits on a Triton and consumes that kind of power? I use 2 group 31s and my only charging under way is my 12 amp outboard alternator. I can run lights, electronics, stereo and even a portable DVD player. I keep 2 cell phones and a hand help VHF charged as well. An auto-pilot can draw a fair bit, but even that won't get you near 400 amp hours a day.

[TritonSailor]

Maybe my calculations of daily amp use is off by a considerable amount. I was trying to figure in use of power that I didn't have to keep under a tight leash. I wanted to be confident that I wouldn't have to watch what I was using, so I took average daily numbers and made them above average. Hirilonde, I don't even have a lamp running on my boat, I'm trying to cover what I "Think" I'll be using on the boat. I Just went back and looked at the website with the T-105's and realized that they are 6v not 12v and that's why they require 4. I'm sorry for wasting space and time on a question I wouldn't have had if I was paying attention! Also, can you use bladed terminal batteries on a boat or do we need to use the auto terminals?

Thanks Again

Jeff

[Tim]

I can't imagine what you'd be running that would cause you to use that sort of amp-hours on a daily basis. I think something is way off in your calculations. I'd recalculate. Remember that nothing on board is going to run 24 hours a day (generally), and therefore won't use its full amp-hour rating X 24 when you're calculating things. Be realistic in your estimating, but don't go overboard.

For purposes of meaningful discourse, it would be helpful if you'd post a list of what you anticipated your daily needs would include.

Having good battery capacity is important, but you don't want to overestimate your usage so much that you have ridiculous amounts of capacity on board. Batteries are expensive, heavy, and take up a lot of room. You don't have the luxury of having as many as you think might be nice--you need to know how much you realistically need, and even then you'll find space is at a premium. And the more batteries you have, the more charging capacity you require in order to be remotely efficient.

Tritons are simplistic, basic boats. Your electrical use will generally follow suit, though this doesn't mean you have to be roughing it either.

[bcooke]

Keep in mind too that your battery bank needs to hold about twice as much as your expected usage. Batteries don't work well if totally emptied every day.

You may have the batteries to store a days worth of electricity but you also need to generate it in the first place. Solar and wind aren't going to make your current estimates which I agree is much too high.

James Baldwin cruised with 200 amp/hours I believe and only added the extra capacity to run power tools later. 200 is 'good enough' for most cruisers. You can't have it all in a little Triton.

[David VanDenburgh]

For what it's worth:

We use two Trojan T-105s aboard our CD36, for a total of 225ah, and we recharge at (often before) 50% discharge. We run all of the electrical items you mention, with the exception of the SSB, and can last for about two days before recharge with heavy consumption - longer if we're at anchor, of course. If I am remembering correctly, our 225ah house bank allows for 77 usable amp-hours, following Xantrex's and Nigel Calder's charge and discharge recommendations. If you're consuming a couple hundred amp-hours per day, you'd need one heck of a battery bank - at least six or eight T-105s to meet your demand. It sounds like an electrical consumption inventory is in order.

Based upon our consumption and cruising style, 225ah is satisfactory for two people living aboard for a month at a time. Doubling the capacity would more than meet our electrical demands - i.e., fans, vhf, depth/speed/wind, radar, gps, nav lights, interior lights, autopilot, occasional laptop and cell phone charging (since computers and cell phones are necessary evils, we don't bother charging them unless the engine is running).

[David]

You really should consider the impact on storage space and recharging models before you set up an amp hour budget. If you are planning a passage across the Pacific in your Triton, you will need every square inch you can muster for stores, not for batteries. The other side of the equation to your ah budget is, of course recharging. With 400 ah if you discharge to no more than the 50% level you have quite a nut to make in finding amp hours to put into those batteries. Sailing mostly downwind will mean a wind generator will not have the effect it would for local cruising, and I don’t know how you would carry enough photovoltaics to generate those amp hours. You will be running your engine for hours on end to bring those batteries up to full capacity.
I would suggest the following;
-Forget the autopilot and invest in a windvane.
-Be prepared to turn your refrigerator off and live without it for those passages,
-Invest in LED lighting, interior and running lights
Now you should be able to operate on a 200 ah house bank. And replenish those hours with a moderate amount of photovoltaics and a little bit of engine.

[Hirilondë]

I'm sorry for wasting space and time on a question I wouldn't have had if I was paying attention!
Thanks Again

Jeff

Bah, you're not wasting space. Installing too many batteries would be. Its far better to learn about what you need before doing it. If it really is a waste of space on the forum, Tim can always delete it quite easily later. Deleting the work you did and the batteries on your boat is a lot harder, and the money is already spent.

There are certainly people who cruise with more electrical demand than me. And what I use shouldn't necessarily be considered ample, average or anything else by others.

[Rachel]

I was trying to figure in use of power that I didn't have to keep under a tight leash. I wanted to be confident that I wouldn't have to watch what I was using...

First of all, know that I'm not saying this in a snotty way, but just in a "fact of life" kind of way :), but on a smaller boat, there's just no way (in my experience) that you're ever going to have a "I don't need to watch what I'm using" mindset when it comes to battery power. Once you have batteries and power, they are always on your mind when you're using up amps :) If not, you'd be thinking of how much kerosene you had left, so same/same.

Actually, it's that way with everything: Water, fuel, amp hours, food... "What do I have left in stores and how much am I using"

A larger boat will have more stowage of all kinds, but then you usually have more crew too. Still, even solo on a smaller boat like a Triton it will be constantly on your mind. I actually thought that "managing" the resources of my "self-sufficient island" was part of the fun :)

[Tim]

Actually, it's that way with everything: Water, fuel, amp hours, food... "What do I have left in stores and how much am I using"

You forgot "money" in your list... :<)

[Rachel]

Oopsie, yes! That one was definitely on the "reserve tank" much of the time :D

[TritonSailor]

Thank you everyone for your responses. I spent some time today refining my amp usage and I don't know how I originally came up with those numbers other than I got a decimal place wrong a couple of times when I was multiplying:) My new figure is 180AH in a 24hr period. I won't have a fridge, watermaker, water heater, water pump. I'll just have Nav electronics running on passages, nav lights of some sort 24 hrs a day, ssb, vhf, laptop, cabin lights, and I can't think of anything else right now. I don't know if I need to have an inverter to run my laptop, if I do then I'm getting one. Based on those numbers, I guess I need a 400AH bank...Saying that, I don't think I'll have room for 4 T-105's will I? Would my best bet be to get an AGM 8 cell? Any particular brands? Are bladed terminals used for marine functions?

Thanks

Jeff

[Tim]

You'll never get 8Ds into a Triton. You virtually need the smaller size of other batteries, and even that's a squeeze. In any event, one 8D produces only the same amount as one pair of, say, T105s. You'd need a pair of 8Ds for your 400 amp-hour capacity.

Depending on your fuel tank situation, a pair of T105s fits nicely in each cockpit locker, at the forward ends. If you have the original fuel tank on the starboard side, though, you don't have access to the space for batteries.

Batteries don't fit in the Triton bilge, nor under the settees unless you raise the height. Your options are quite limited, really.

[bcooke]

My new figure is 180AH in a 24hr period.

That's still quite high unless you have airconditioning or refrigeration planned.

I think I am not alone in saying I am curious what you plan to hook up to the electrical system that would use that much power.

Now might be the time to mention Lin and Larry Pardey and their 'Simplify' mantra.

Tritons are little boats after all.

[Rachel]

I'll just have Nav electronics running on passages, nav lights of some sort 24 hrs a day, ssb, vhf, laptop, cabin lights, and I can't think of anything else right now.

Just a note in case it might help you to refine your figures: I would only figure on running nav lights for about 12 hours per 24 hour period on passage, and even then it would just be a masthead tricolor (not multiple lights like you'd use for steaming) -- and things like SSB and VHF only take (much) power when you're transmitting, not when they're on stand-by. For even less draw, you might not even leave an SSB or nav laptop on continuously (even on stand-by) if you're trying to save power, but more use them in brief spurts.

I don't know if I need to have an inverter to run my laptop, if I do then I'm getting one.

You can run a laptop off an inverter, but you don't need to. I have a 12v adapter for mine. I believe that's more efficient anyway, as you lose a bit converting up and back.

Basically, while a large battery bank never hurt anyone in the amp hours department, you'll want to be thinking "conserve" all the time on passage, unless you've got really super charging (replenishing) systems. Even then it's good to go with a "what if these all give out and I have to finish the voyage on the amp hours I've got right now" mindset, in my opinion.

Hmmm, I'm starting to sound like a broken record here, but same goes for all your other resources. Water: What if the trip takes much longer than expected; what if one tank leaks or becomes contaminated; Food: What if things unexpectedly spoil or get wet; etc. etc.

I heartily agree with Britton on keeping it simple. I like simple even in bigger boats, but the smaller the boat the more I'd highlight the simplicity. Crammed systems are even less fun to work on than "roomy" ones, and it's no fun sailing 4" down on your lines.

One thing you might do is decide -- out of all the possible "luxuries"-- which one or two you really, really want. Seems like most people do have one or two things that they value above the others, and then you could focus on providing yourself with those one or two things, and keeping the rest dead simple. You'll probably feel less deprived that way than if everything were spartan.

Also, while there's no harm in planning for offshore features now, in terms of space and execution, it's often good to wait on electronics type purchases until the last minute. They tend to get better and cheaper (not batteries, which are going up in price; but still nice to have them fresh).

Rachel

[David]

Am I missing something here? How in the world do you get 180 ah per day out of:

<<I'll just have Nav electronics running on passages, nav lights of some sort 24 hrs a day, ssb, vhf, laptop, cabin lights, >>

Navigation instruments are negligible, nav lights are only used at night, ssb is only used briefly, vhf in the middle of the Pacific, not at all, laptop would be used briefly as well and cabin lights for a Triton--how many could that be?
You are still looking at 400 ah if you are estimating 180 ah days. How do you propose to recharge all that capacity?

[Tim]

I agree, again. We all seem to be saying the same thing over and over. Something is far wrong in your calculations. I'd be surprised (amazed, even) if you actually were able to use even 50 amp-hours in a day, even with "luxurious" usage of lights and other equipment.

The bigger question, one that again has been raised several times now in this thread, is how you'd plan to replace the amp-hours. You simply won't have the charging capacity with typical alternators, small engines, and the other limitations on a boat of this size. Even with wind and solar assist (which at best are minimal helpers), you'll never make it. This means you'd be down to zero battery capacity within a matter of only a few days.

One thing one can never do on any boat, big or small, is be complacent about electrical usage. One never leaves unnecessary lights burning, or laptops running when not in use, or anything else that's not being used, for that matter. I think you're using one-hour ratings for these appliances times 24 hours to come up with your daily usage--and that's not how it is, nor can it possibly be. Clearly it's impracticable.

It's OK if you want to fill your boat with batteries, but there are some experienced voices here suggesting that perhaps things are different than you're coming up with. And if you do manage to use this many amp-hours in a day, rest assured you will never be able to replace them.

Post an itemized list here of your electrical equipment and the manufacturer's listed amp-hour rating for each piece, and I bet you'll get some more valuable feedback that will help really square away your electrical power needs.

[TritonSailor]

Ouch!!!Tim you are right, I am using daily values and am multiplying them by hours in a day, but Nav lights are the only value I'm assigning 24 hrs to. For some of you responding I'm sorry if you think that I'm naive with my "luxuries", but name something on my list of items that you wouldn't have for TransPacific passages...I'm not talking about the 2 day jaunts down the east coast, I'm talking a 2-4 week passage. Now you also must remember, at this point, my total knowledge of this whole electrical subject is summed up in about a month of reading. I'm sorry if my figures are out of bounds, but I'm not finding many manufacturer's who provide ah output for their product. I really can't come up with a detailed list at this moment because I'm currently sitting in my car with no heat in front of a wifi spot in this NE cold snap because I don't have internet so I can save money for my luxuries.

Jeff

[David]

The subject of onboard power is something that takes a lot more study than a month of reading. It is a complicated balance of critical compromises, and the smaller the boat and longer the passage the more critical the subject becomes. In my opinion you must start the calculations from the point of recharging--look at how much capacity you can put into a house bank and let that determine the size of and load on your house bank. For a long passage you need to also look at redundant, isolated and protected systems for critical components. Then develop an amp hour budget, remembering that for the most part 11 watts equals an amp (your batteries will not be at 12 volts when your house bank is in use). If you use a light that has a 20 watt bulb for an hour, that is essentially 2 amp hours removed from your house bank. It will take about 24 watts of recharge (about 120 percent of what was removed) to replace those watts, but the time to recharge the house bank is what is critical. With a three stage charging model, it is the absorbsion stage that takes a lot of time and can't be rushed. The larger your house bank and the larger its discharnge of amp hours the more time is needed for the absorbsion stage to be completed.
I suggest strongly that you read Living on 12 Volts, written by Ample Power.
http://www.amazon.com/gp/offer-listing/ ... dition=all

Good luck,

David

[TritonSailor]

Aqua Signal Series 40 Tricolor 25w red/green 10w white=35W
35w/12v=2.92Amps

2.92Amps*8hrs=23.36AH

Now I was under the impression, by regulations, sailing vessels under 20m need to have nav lights on at all times. Which to me means 24 hrs/day.

2.92Amps*24hrs=70.08AH

Now this is where I have been getting all my figures. If I did it wrong that's why it's so high, not because I'm unrealistic about my usage.

Jeff

[David]

The tricolor only uses one 25w bulb, so your amp hours for that light would be a little over 2 amps per hour or about 16 ah per 24 hours. You only need to run your lights at night; there is no requirement to run them during the daylight hours; only sunset to sunrise. The Aquasignal 40 can also be configured with a 360 degree white anchor light that uses a separate 10w bulb. Both cannot be lit at the same time.

Even with your calculations, I still don't see where you are getting 180 ah per day...

[TritonSailor]

:(

[David]

I'll let someone else respond to this.

[Maine Sail]

My new figure is 180AH in a 24hr period. I won't have a fridge, watermaker, water heater, water pump. I'll just have Nav electronics running on passages, nav lights of some sort 24 hrs a day, ssb, vhf, laptop, cabin lights, and I can't think of anything else right now. I don't know if I need to have an inverter to run my laptop, if I do then I'm getting one. Based on those numbers, I guess I need a 400AH bank...Saying that, I don't think I'll have room for 4 T-105's will I? Would my best bet be to get an AGM 8 cell? Any particular brands? Are bladed terminals used for marine functions?

Thanks

Jeff

Wow that is still HIGH !!! Some points to ponder..

#1 My advice would be to first invest in a battery monitor like a Link 10 or a Xantrex XBM. This will give you a far more accurate read on consumption and will literally be the best money you've spent in a long time!

#2 My second bit of advice is save money on batteries and spend money on LED nav and cabin lights. They are simply amazing if you buy quality bulbs. If you buy cheap bulbs they suck.

For interior the Sensibulb is, right now, the best of the bunch. For nav lights buy AquaSignal series 25 or 40 and replace the bulbs with Dr. LED bulbs. This is the least expensive USCG legal way to get LED nav lights. Dr. LED basically purchased AquaSignal 25 & 40 series fixtures, inserted their bulbs, and sent them off for certification.

Sticking "Joe's Superliscious LED's" bulbs into your existing fixtures is not a certified nav light and leaves you open for liability in a night time accident.

#3 Unless you own a Mac with a MagSafe cord DO NOT use an inverter to power your laptop. Doing so will cause you to see inefficiencies of as much as 30%. Laptops already run on DC and by using an inverter you are doing this DC to AC back to DC. Buy a DCspecific power cord for your particular laptop.

#4 Get a plotter they use a LOT less power than a laptop!!!

Please read this to get an understanding of why you should use 12v for your laptop over 120.

Inverter In efficiencies (LINK)

On the computer / plotter thing here are real numbers;

Garmin 3205C (radar not on) = .75 amps per hour

MacBook Pro 15" through 400W inverter = 4.2 amps min to 6.8 amps max per hour.

[Rachel]

TritonSailor,

I understand that you're talking about passages. And the subject of what's necessary or desirable to bring along is a very subjective one that's subject to endless debate. In the end, each "boat" (i.e. the people on it) decides what's right for them. We cruised on the small and simple end of things (for this day and age), and I liked it that way, but you'll find all kinds out there. That said, the ones with more luxuries are usually on 40+ footers, since it takes more money and space.

My cruising bud and I crewed through The Canal on an Amel Super Maramu (50-foot-range), and it was quite lovely to be woken up to a fresh cup of espresso made on a full-sized Italian machine, and then to get ready for my day in my own head, with hot running water, that was part of my own forward cabin :) Snacks were French cheese and olives, and of course we celebrated our successful transit with Champagne in real glass flutes! I probably don't even need to mention the "push button" sail deployment, or the refrigerator/freezer; those go without saying ;)

Then we got back to our boat. No refrigerator, no "running" water, and even in the tropics, the fans were on only when we directly needed them (thank goodness for wind scoops). But there's no place like home, and we loved our boat-sweet-boat. It was ours, and it felt manageable.

And I jest above, but even on a 64-footer that I've helped deliver - which carries 750 gallons of water in four tanks - the four of us conserved. Even though "by the math" we didn't need to. It's just a good habit (and indeed, one time a malfunction led to the direct loss of nearly 300 gallons before we realized what was happening). And then too, we knew that we'd have to pay for water by the gallon to replenish, and that the small islands where we were headed only have so much water. Even when opening the freezer for ice cream on Day 6 (hee!), we planned ahead, thinking "Okay, the ice cream is in the left rear corner, so I'll just reach in like so," before opening the lid. So it's never quite like on land, where you have an ample, easy supply of things.

I guess if I were you, I'd start from the other direction, and start to list what you really need, and work up from there (vs. down from what you "can't have.")

For example, unless you're really exceptional (like you're an ancient Polynesian, or Gerry Speiss, etc.), you need a boat that keeps the water out, the stick up, and the rudder on. That's square one. For yourself, you need water, food, clothing, and a place to sleep. For navigation you need a compass, a chart, and nav lights. And for stopping you need an anchor and rode, an anchor light, and it's really nice to have a dinghy.

You can work up from there, as budget, boat size, and inclination allow. For myself, I detest things that are not working, so I try to think of alternatives that are simple, robust, and self-fixable. (Yes, the laptop I'm typing on does not fit that category, and yes I had to be drug kicking and screaming into a car with power windows - ugh.)

So, for example, a windscoop instead of (or at least to reduce the use of) fans; a wind vane instead of (or to reduce the use of) an autopilot; foot pumps instead of electric for water; icebox vs. refrigerator; manual windlass vs. electric; garden sprayer instead of shower.

But it's all in degrees, and all subjective. I could say "handheld GPS vs. chartplotter," and someone else would say "sextant instead of GPS." Or "sheet-to-tiller steering, not a windvane!" None of them is right or wrong, but they are decisions to be made, and they will change the quality and (unless you're rich) length of your voyage.

I don't know if you've read the Pardeys' books, but they are good inspiration for simple, self-sufficient, sailing (as Britton mentioned above). I say "inspiration," because I know that even though I loved their books, I won't likely be building my own boat or sailing engineless. But the outlook holds, and even if you only pick up a few tidbits, it's worth it. James Baldwin's site is a good one (www.atomvoyages.com)(I think you said you'd read it), and for a like-minded group of voyagers on small boats, you might like to read www.sailfar.net

By the way, I don't mention the above resources to drive you away from here; indeed, I hope you'll stay, because I'm really interested in what you're doing, and I think this forum has a lot to offer. But they all have their own slant, and so sometimes it's nice to belong to more than one, or to check others out too.

I'd better stop now, or Tim will move this to "Ramblings" ;)

Rachel

[Rachel]

I'm sorry if you think that I'm naive with my "luxuries", but name something on my list of items that you wouldn't have for TransPacific passages...

I'm interested in your list, but I think I've somehow missed it - can you point me to it?

Thanks,

Rachel

[Rachel]

Unless you own a Mac with a MagSafe cord DO NOT use an inverter to power your laptop. Doing so will cause you to see inefficiencies of as much as 30%.

Maine,
I meant to ask you why a Mac with a MagSafe cord is not inefficient to run with an inverter? How does it use the power differently?

Thanks,
R.

[Shoalcove]

I've read this with interest since I'm doing some electrical work this year as well. 180-200 amps seams like a TON on a small boat without a fridge and watermaker. Again, I agree with the others that there is likely a error. I fully agree with Mainesail that it is very effective to reduce need rather than increase capacity. I'm planning to switch more lights to LED's. This electrical stuff adds up really fast when you decide you need an array of solar, wind gens and Hi-output alternators to feed the battery beasts. I don't have a Triton but they seem like a boat that will thank you for not loading them down with too much of this stuff. Also you'll be cruising sooner! Best regards, David

[TritonSailor]

I agree with all of you, it came down to a calculation error and I spent a lot of time yesterday looking up individual equipment usage and the correct formula and it came out to about 90AH. I put up a list, but based on a response from one person I didn't want to start another foray into the matter. Suffice to say that it was my mathematical error (I've been out of college a long time:)) Based on that number, I'll figure out what I need to use for batteries and ehat to get for batteries. As Tim pointed out repeatedly as well as others, the room is an issue. But based on my new outcome I will have a battery bank to cover it even if I have to put what little carpentry skills I have to use. :O

[Tim]

Be sure to pick up one of these. While techically only required on board for boats over 39', everyone should have it because it is, after all, THE text for the rules of the road and lighting requirements. Not enough people know even the most basic of the rules and lighting requirements.



Good luck with your batteries and electrical system. I think all that needs to be said in this particular thread has now been said.

[JonnyBoats]

I totally agree with Tim that everyone should have a copy of the Navigation Rules (COLREGS). For those of you who would like a free, electronic copy, you can obtain it at: http://www.navcen.uscg.gov/mwv/navrules/navrules.htm

[Maine Sail]

Unless you own a Mac with a MagSafe cord DO NOT use an inverter to power your laptop. Doing so will cause you to see inefficiencies of as much as 30%.

Maine,
I meant to ask you why a Mac with a MagSafe cord is not inefficient to run with an inverter? How does it use the power differently?

Thanks,
R.

It IS inefficient to run a Mac with an inverter. Unfortunately, Mr. Jobs in all his infinite wisdom, has a patent on MagSafe and will allow NO licensing and hence NO 12V adapters for Macs powered with MagSafe!!

So much for Macs & the business traveler...!

[Rachel]

Maine,

Thanks for the info on the MagSafe. I see what you mean now. Ugh, because I use my 12v adapter all the time, and my iBook is not getting any younger. That's going to be a dilemma (sure, I have a little inverter, but that's not the principle!).

TritonSailor: Sounds like you're on your way to a good power management set-up.

R.