Category Archives: Outfitting

Lithium Iron Phosphate Batteries

Using Lithium Iron Phosphate Batteries to Repower

Anyone interested in replacing their marine batteries should read the story of catamaran owners who recently repowered their boat. They replaced their AGM deep cycle batteries with marinized lithium iron phosphate batteries – for a lot of good reasons. Lithium iron phosphate batteries outperform lead-acid across the board:

  • Charging efficiency – Lithium accept charge much more quickly – without having to slowly charge  the last 15 – 20% typical of lead acid. Kill your generator sooner!
  • Discharge efficiency – Unlike lead acid (AGM, gel, or wet cell), lithium batteries can be discharged quickly without heating excessively and losing much of their rated amp-hour capacity.
  • Depth of Discharge – Lithium batteries can be routinely discharged to 70%, versus 50% for lead acid batteries.
  • Internal resistance – Lithium batteries are highly efficient, returning nearly the same number of amp-hours as were required to charge the battery.
  • Storage – Similar to AGM, lithium iron phosphate batteries have very low self-discharge rate, allowing long-term battery storage without concern for the batteries going flat.
  • Stable output – Lithium batteries maintain their full nominal voltage, even when being heavily discharged – until they're 70% discharged.
  • Expected life – Lead acid last approximately 1,500 cycles if they're not discharged beyond 50% too often, while lithium claims 5,000 cycles at 70% discharge.
  • Cost – Lifeline AGM were priced at $3,600 with 252 usable amp-hours, versus Winston lithium batteries, which cost $2,365 and provide 280 usable amp-hours.
  • Weight – The lithium deep cycle battery bank weighs 157 pounds (71 kg), while the AGMs they replaced totaled 423 pounds (192 kg).
  • Environmental – Lithium batteries are far less toxic than lead acid batteries.
  • Safety – Lithium batteries don't generate flammable gasses while charging. Perhaps of interest – you can watch a LiFePO4 battery being cut and crushed while still powering a light.

The downside is that you need to have an effective battery management system which both limits the voltage while charging and shuts off loads if the voltage while discharging drops too low. Violating either of these rules can substantially reduce battery life.

If you're interested in reading a bit more about lithium iron phosphate batteries, there's a thread at cruiserforum you can peruse – or you can fire up your favorite search engine.

I'm still just thinking about installing lithium iron phosphate batteries, but they look good from here!

Outboard Weed Guard

Outboard Weed Guards

In my area (western Lake Erie), June brings weeds – lots of weeds. I've hunted all over for an outboard weed guard to keep weeds from balling around the propeller. It's no surprise that outboards don't have much thrust or steerage when the prop is weed covered. In addition, weeds clinging to your propeller could damage the seal or block cooling water intakes – either of which can ruin your whole day.

The best solution has been to put the outboard in reverse for a few feet to let everything unwind and disperse. That solution hardly qualifies as an outboard weed guard though. If you're at the tiller and the gearshift isn't easily reached, constantly putting the motor in reverse is a nuisance and a distraction. It can be a disaster if weeds strike as you approaching an obstacle. This year I'm going to fight back. I didn't find a suitable outboard weed guard, but I did find a weed cutter that may work well.

The weed cutter is a fairly tough plastic, intended for fishing boats commonly used in heavily vegetated waterways. The cutter is called “Moss Hawg“, and it's designed to fasten easily to electric trolling motors motors commonly used while fishing. As it turns out, the Moss Hawg can be modified to fit many small outboard motors by cutting the plastic support ring and gluing it to the bottom end of your outboard. The ring feels like HDPE, a plastic which doesn't glue well. Fortunately, West System markets G/Flex, a glue which is both resilient and tough – and engineered to stick well to plastics, as well as metals, glass, wood, fiberglass, etc. According to the developer, it will even stick if applied underwater! The picture to the right shows it glued to the bottom end of my Bigfoot (click to enlarge). The support ring for the Moss Hawg is round, and the casing at the bottom of the Bigfoot isn't – so the G/Flex between the two is fairly thick in places. Regardless, the G/Flex has a firm hold of both the Bigfoot and the Moss Hawg, and the serrated blades sweep the hub right up to the roots of the blades.

I saw my first group of weeds yesterday, and will report back in a month or two – as soon as I have a solid feel for how well the combination works. It's not an outboard weed guard, but if it cuts weeds as advertised, I'll be a happy camper!

Building a Better Composting Toilet


The Thunder Mug

I'll be taking the shrink wrap off Magic Moments shortly and putting the arm on my brother to take the trailer, pick up the boat at the ramp, and bring it back to the house. (Are ya with me here Kevin ol' buddy??) Once the boat is back, I can clean the hull and deck, finish installing the new outboard motor mount, measure for the stainless steel bimini parts, etc. I have a lot of design work to do too: the rigid solar bimini, a new composting toilet, the new mast lowering system, etc. – all which have to come into focus on the computer before any dollars begin to fly. I haven't used SolidWorks (the CAD program) for years, so I expect to be staring at a blank screen for a while and making a lot of dumb mistakes while I get my head around it again. It's a pricy program, and one I wouldn't even have were it not for the Army's decision to fund a few years worth of R&D for improvements to conventional suspension systems currently on their vehicles. Soooo… I have broom out the CAD cobwebs between my ears before getting carried away with design and validation of those new boat systems.

I did make a bit of progress with my first CAD effort last week, beginning the design for a different type of composting toilet. There are already a variety of composting toilets on the market, but I'm always trying to make a better mousetrap. In particular, headroom on Magic Moments is limited, so the head itself needs to be close to the ground – only a foot (or 27 cm) from top to bottom. Natures Head and Air Head make some (pricey) composting heads, but they're too tall (about 20 inches, or nearly 51 cm). I'm 6'2″ (the metric me is 188 cm), and sitting on one of those commercial composting toilets would require that I have an open hatch directly overhead. Interesting visual, isn't it? For those who are curious about my weight, I'm just a little over 14¼ stone – you can work out the imperial or metric equivalent yourself!

There are a couple of issues I'd like to address in a new composting toilet design:

  • I don't believe existing composting toilets are legal for boats in Canadian waters. Part of Canadian maritime law requires that the head must be permanently affixed to the boat, and must be set up so the only way to empty it is to use a shore based pump out facility. Many port-a-potties commonly installed on smaller recreational vessels are illegal under this second criteria , since the head cannot legally be emptied by removing a tank and taking it ashore to empty it. The same holds true for composting toilets; no bags or jugs can be disposed of or emptied ashore.
  • In addition, a composting toilet would ideally allow solids to sit undisturbed a month or more while completing the composting process, but units currently on the market such as Nature's Head, Air Head, and C-Head have only a single composting chamber, so when it's time to empty the unit, there will be fresh umm… payload in the mix. You can read more about other conventional composting toilets online; you'll find that many land based composting toilets are designed to hold compost in a second chamber for a full year before being emptied. The design I'm working on uses 3 common 5 gallon buckets (about 19 liters each for readers in most of the world). The proposed design segregates the composting bin into two chambers for solids – and yes, ultimately there will be a liquid compartment too! A moveable divider will isolate one solid chamber from the other, and helical agitator bars will help push the composting material away from the drop zone. Whew! enough with the euphemisms…

When in service, the user turns the central rod after each use, causing the helical bars along the barrel walls to aerate and move the compost laterally within the barrels. There will be a divider secured to that central rod, which will normally be at one end of the threads on the rod or at the other end. When one side of the composting toilet becomes full, the user would reverse the direction of rotation of the rod – moving the divider to the other end of the threads on the rod. The ‘full' side of the head would then be isolated, and able to compost in peace while the other side took over ‘active' duty. Compost on both sides of the divider is aerated each time the user turns the rod.

Incidentally, the term ‘Thunder Mug' was used by my Dad to refer to the little stool and mug my brothers & sisters & I used to potty train. It just seemed appropriate for this little venture – and it amuses me.

There's more CAD work to do, but hopefully the design intent is apparent. Stay tuned for part 2 of this exciting saga!

Microwave on Board?


Fast Meals While Cruising

Living and cruising long term on a boat requires some adjustments, as most boats have a fraction of the space available in a small home – and Magic Moments is a small boat. Think of it as living in a closet. Space is at such a premium that everything you own needs to do double or triple duty – a five gallon bucket might be key to cleaning your laundry while underway, carrying tools aloft to repair the masthead light, rinsing salt off the deck, dragging it overboard to slow the boat in stormy weather, or using it to bail the cockpit if you've been pooped by an unruly wave. I hold that same ‘double or triple duty' standard when considering the use of a microwave on board. My post about making bread in a pressure cooker touched on using the pressure cooker in a microwave; here are some further thoughts. Why consider using a microwave when gimballed burners have long been the norm on board cruising vessels?

The answer is somewhat convoluted, and goes something like this:

  • A microwave lets me cook quickly in the storage container (read: Zip Lock bag or Tupperware container), without having to mess up a lot of pots & pans or dishes. The associated reduction in water consumption for cleaning dishes is also noteworthy.
  • The microwave will heat just the food, and not the container it's in or the surrounding area. The boat isn't air conditioned, so this could be a good thing in tropical areas. There may be times I'd like more heat, but I'd like to control how much additional heat is added below decks. Similarly, any water vapor from cooking is limited by both the container and the microwave – also a good thing below decks. Using conventional gimballed burners to cook (or having any open flame below) adds moisture to the air, and can make life below unpleasant.
  • There is no risk of a fire or explosion otherwise associated with propane, butane, or alcohol stoves, nor is there any danger of putting something down on a hot burner. Power will come from two solar panels (240 watts each), run through MPPT controllers, and stored in lithium batteries (LiFePO4) – the subject of another post. Renewable, clean… you've all heard the marketing drill. What you may not have heard is that installing the system may qualify for an energy tax credit (yet another post).
  • The microwave can control the food being cooked while the boat rolls or pitches, without having to resort to gimbals and pot holders. If pushed, I can stuff old socks and tee shirts into the microwave to hold food being cooked in place while underway. Appetizing, eh?
  • I can use small zip-lock type plastic bags designed for steam sterilization of baby bottles to cook different foods simultaneously in the microwave or in the pressure cooker. At only 2.5 quarts, the pressure cooker is too small to stack internal dividers and cook different parts of an entire meal all at once. I can easily stack the sterilization bags in the microwave or pressure cooker though.
  • I can easily cook small, pre-packaged meals I've prepared and stored, and the nature of the beast makes using a microwave while underway quick and easy – very much a plus if the boat is dancing while I'm trying to put together a hot meal.
  • I can do a limited amount of searing of meats or reheating pizza (and keeping it crisp) in a microwave using a browning dish (you've got it, ‘nother post), but to truly grill something, I'll have to press the propane powered grill on the pushpit rail into service. Yeah, it's powered by propane <groan>, but at least the propane won't be stored or used in the cabin.
  • It's never really comfortable being on a sailboat in a thunderstorm with lightning providing a light show – but you can use the microwave as a Faraday cage to help protect some of your electronics.
Click for information about inverter microwaves

The bottom line: I guess the microwave has a secure place on board (I'm eyeing the small Panasonic inverter microwave pictured to the left), but the question remains – where will it fit?

It's time to become re-acquainted with the use of CAD, and to realistically plan how all the pieces of the puzzle will come together by making an accurately scaled drawing of the interior of the boat, and seeing how all the pieces can best come together.

Using Legos to Raise and Lower Your Mast?


 Raise and Lower Your Mast – While on the Water

In my last post, I indicated that this post would be about making warm, aromatic bread in a microwave pressure cooker. I lied. I will get to that post next, promise.

I mentioned a radical new mast lowering system in my first post back in January though, and mentioned it again in an ongoing thread about cruising around the Great Lakes that Ron started on a Rhodies discussion forum (that's what card-carrying owners of Rhodes 22 sailboats call ourselves). The new system allows single-handed sailors to raise or lower sizable masts while on the water, even if the water isn't entirely smooth. The work can be done from the cockpit (for the most part), and leaves the mast centered in the mast crutches – there is no need to shift it forward or aft before securing it.

Trouble is, I sort of indicated I'd get a video up this week showing the system in action, so now
I've gotta put up or shut up – so please be patient with a little delay before I finally unveil that loaf of bread.

And… just so you're not expecting a professionally produced video, know that this is an unscripted and unrehearsed demonstration of the mast lowering system – using Legos as the prototype medium. And now that I've set the bar so low that no one could possibly crawl under it – without further ado…

If the video above won't stream even after you've given it a few minutes, you can download it by right clicking on the filetype you'd like (mp4, ogg, or webm), and save the file to your computer.


Some things I didn't throw into the video commentary:

  • The geometry of the system actually lifts the mast slightly, and would allow a mast to clear a step of several inches. It won't do any good for keel stepped masts, however.
  • As shown in the video, you can pause while raising or lowering the mast, whether to pass under a bridge and put the mast back up again immediately, or to disconnect / reconnect wiring between the mast and the boat.
  • This should work well with larger masts, as the lower quarter of the mast counterbalances the next quarter of the mast (up to the half way point), and the halyard from the bow to the mast head helps support the top half of the mast. I'm working with the Rhodes' in-mast furling system, and anticipate no problems with its weight, particularly given that the mainsheet has a 4:1 purchase on the line attached to the mast. Note that you'll have to tie the lower end of the mainsheet to something other than the traveler on the Rhodes – the backstays probably won't provide adequate support while slack. I intend to move the traveler overhead to the front of a rigid bimini.
  • There is no need to loosen the rear lower stays or the backstays on the Rhodes. The shrouds will need to have a little slack in them, and the forward lowers will need a bit more slack in them (possibly disconnected entirely). The jib or genoa furler will need to be disconnected entirely before lowering the mast.
  • Another comment specifically for the Rhodes – it should be possible to use the hardware for the rear lowers to secure the lower end of the 6 foot poles.
  • The system will be able to support the mast while motoring under reasonable conditions. If you'd like to put up a sail however, you need to reconnect and re-tension the headstay, the forward lowers, and the shrouds. You should reconnect and re-tension the rigging if you'll be in rough weather though (even if you only intend to motor) as the upper end of the mast could whip around unsupported – and a bent or broken mast could ruin your whole day.
  • I know… the mast is too far forward in the model; work with me here though, will ya? The prototype was designed with Crayons and fabricated with Legos!

I'll add another post in a week or two about design and construction considerations. Life beckons and time is short, so that's it for now. Your comments – good or bad – would be appreciated. They may make for a better Lego Mast System 2.0!

Musings about cooking


Using a pressure cooker in a microwave

I started giving some consideration to life on board while cruising, and cooking came to mind. Magic Moments is equipped with a single butane burner – but it's difficult to find fuel, it has no gimbals, and there's no way to hold onto a pan when the boat pitches and rolls. The bottom line is that I need something different to heat food. What to do?

It would be great to avoid the need to have liquid or gas fuels in the cabin, but the only other option is to cook with electricity – and electric power may not be readily available while afloat. I plan to have two sizable solar panels as my bimini though, about 240 watts each, and use them to charge some relatively inexpensive lithium batteries (LiFePO4 batteries). A microwave is probably the most energy efficient use of electricity to cook, but trying to install a microwave in a tiny galley and powering it from batteries is a fools errand. Still… I've been called worse.

OK, if I steal some of the space allotted to the starboard v-berth, shift the location of the new composting head… maybe. Time to break out the crayons and do a little more accurate planning.

While reading about cooking on board, I ran across several cruisers extolling the virtues of pressure cookers to speed up meal preparations and even bake bread while on board. Hmm… using a pressure cooker – inside a microwave?? Yes! There are several available – but further hunting online shows most designs are fairly cheesy. I found that Nordic Ware makes the Tender Cooker, a 2.5 quart non-metallic pressure cooker that fits in many small microwaves. Not only would I be able to capitalize on the microwave's efficiency, I could compound its efficiency by cooking in the little pressure cooker inside the microwave.

My next consideration was to address the occasional desire for browning or searing meat in a microwave. It turns out that there's a pan for that too! Corning Ware makes a browning dish that has a special tin oxide coating on it, designed especially for the task.

That's enough for today's post. Time to search for a good deal on the two pieces of cookware – I may as well purchase them and use the winter months to see how well they stack up for cooking. I can even use a kill-o-watt meter to see how much power the microwave will use for meal preparation.

I'll be back in a future post to let you know how they work out. Meanwhile, pick out one of your own dreams and chase it!