Trimaran - Especially Searunner - Owners

[Buzzman]

LOL... yeah, I'm an icebox guy who wants a fridge....

I actually have an older 35L 12-VDC chest fridge/freezer but it's fancy shmancy digital electronics have eaten themselves, so it will eventually be disassembled, plumbed into the 24' and re-wired with 'basic' controls. Like a knob to turn to adjust the temp. That's it.

My understanding is that windvanes don't work as well on multis, but am happy to be corrected by anyone who has the opposite experience. Something to do with the lack of difference between actual and apparent wind, IIRC...

BUt, if you want DIY wind vanes, here's agood place to start
Advanced

Also search for 'sheet to tiller self-steering' as there's loads of ways to rig a self-steering system off the jib or main, attached via lines and blocks to the tiller, which are reportedly very effective on long passages, and use no power at all.
Sheet-to-Tiller Self Steering

The kind of electric tiller pilots commonly used seem to suffer from water ingress and must be protected from weather and spray, but are less than helpful in some wind/sea conditions, having limited response. Good for when motoring.

Again, haven't used them, just reporting what others (who have used them) have reported.

Ditto wind generators. They work better when at anchor than while sailing, allegedly.

But for all the added complexity, noise, vibration, miserably low ouptuts and multitudinous reports of failures of pretty much ALL marine-type wind generators, it's probably cheaper, easier and lighter to just add an extra solar panel and extra lithium battery storage.

I've been told EV Power in Western Australia are good for batteries, and have even seen reports of boaters who have bought batteries from them who don't live in Oz. I am not affiliated with them at all.

Another good source of knowledge on lithium batteries and their management systems is the EV forums, as most DIY Electric Vehicle owners prefer LiFePO4 lithium batteries. Many have built their own from CALB cells or Thundersky cells, but unless you are an elctronics expert, I wouldn't reccommend that approach.

Battery management systems (BMS) are a must with lithium, especially LiFePO4, as the cells MUST be charged evenly, which the BMS 'manages'.

At least LiFePO4 batteries are unlikely to catch fire, like some other lithium batteries....

[owly]

Originally Posted by Buzzman

The point about ice boxes is that it's no longer as easy as it was back in the day to find 'block' ice dockside, or even nearby.
These days commercial icemakers produce 'extruded' ice which forms small blobs or 'cubes', which are then bagged in small 2-5kg bags. The greater surface area on this type of ice causes it to melt rapidly, within a day usually, (unless you have a super-insulated icebox), so ice is no longer an especially viable 'cruising' option unless you can get to an ice source every couple of days. Block ice can last days longer.
So while ice is viable for coastal cruising, it's not much of an option for ocean cruising - unless you have an onboard freezer, and in which case, why not a fridge also? Or instead?
Portable RV chest fridges are often seen on coastal cruising boats these days, even on ocean cruisers, but seldom do you see them properly insulated.
Having said that, for the minimal cost incurred, simply disassemble the chest fridge and use its compresor, condensor and internal parts, and simply throw the rest away, or use it as a 'box' to store something else.
So-called dedicated 'boat fridges' tend to be highly specialised and fitted by wounded bulls who know how to charge. But to be fair their costs reflect the labour involved, which a good DIY person can supply themselves.
My point being, it's relatively simple these days to fit viable 12-VDC refrigeration even to a smaller cruising boat, like a 31' Searunner.
'Back in the day' this was not so much the case.
I totally get the minimalist idea of less is more, especially in terms of complicated systems like refrigeration, or A/C....
But my point about the light weight of lithium batteries was intended to indicate that the additional energy storage to run a fridge is now possible without the weight penalty (and effect on cruising displacement) of the larger number of much heavier lead acid batteries that would have been required previously.
Which would you prefer? A 2kg battery or a 20kg battery?
Think about what a case of beer weighs....24 X 375ml = (approx) 9kg.
So taking lithium batteries instead of lead aboard enables you to carry two cases of beer without a weight penalty.
What's not to like?

Batteries are heavy, expensive and have a finite number of cycles. I'm quite familiar with lithium batteries, as most of us are these days. The high energy density and large number of cycles make them attractive......... but there is a high upfront cost, and some other issues. My point has always been that the way to mitigate all of these issues is to use batteries as little as possible. To use energy directly as it is produced, whenever you can. Every KWH that passes in and out of your battery system has a cost. A cost in battery life. I've always thought and lived "outside the box". It's the foundation of my "success" such as it is. My customers call me for solutions, often when conventional solutions have failed to resolve the problem. I'm not "anti convention"..... It's the first place I look. Here I see fewer lighter, more efficient batteries combined with less usage of them. Making ice while the sun shines saves you money, and saves you weight. Running your electric water maker when you have surplus power, rather than relying on battery storage, likewise saves you money, and weight. Reduce random demands that ignore supply, and you are money ahead. What battery reliant systems to I really need? Very few actually. We have a habit of generations of wasteful use of energy. Nothing is likely to convince me that conventional refrigeration makes sense on a boat......... for me. I thought I'd share my ideas on that, in case anybody was interested. You've clearly talked yourself into conventional systems......... and that's OK, but it's not for me. I see what for me is a better way. H.W.

[Buzzman]

The big differences between lead acid batteries and lithium batteries - especially in regards to cruising displacement in multihulls are:

- the weight difference. One tenth the weight - but four times the price.

(So although *individual* battery packs of a *typical* battery size may be only half as much as the same footprint lead acid battery, the energy density is four to five times as great, in terms of *usable capacity* over the batteries life cycles)

- the energy density and "usable energy". Lead acid batteries are well known to degrade *rapidly* if discharged by more than 30% of their rated capacity, and the optimum for max life of lead acid is 10% discharge rate.

- Lithium batteries, and especially LiFePO4 batteries, can be discharged to 80% capacity almost endlessly, without any serious degradation. And their rated lifespan - number of cycles - is usually four to ten times that of lead acid batteries.

- the life cycles: lead acid, around 1200 cycles @ 30% DOD; LiFePO4 around 2200 cycles at 80% DOD (or 7000 cycles @ 30% DOD for a direct comparison). Or max 3yrs with lead acid; compared to almost 20 yrs with lithium.

So on weight and energy density and especially *usable* energy over the same life cycle, lithium wins hands down.

You need to compare the cost per *usable energy* to get a fair comparison.

For example, the standard N70 100Ah deep-cycle lead acid battery is around AUS$250.

BUT....although rated for 100Ah, really it can only sensibly be rated as a 30Ah, as its lifecycle depends on not discharging it more than 30%.

So to get 100Amp hours of *usable* energy from lead acids you need at least 4 of them, or around AUS$1000.

This is 100kgs of batteries...!!! (at 25kg per battery).

And takes up the real estate of 4 large batteries the size of the starter battery on a 4x4.

100Ah Lithium LiFePO4 packs from EV Power are not cheap, weigh around 12.5kg, but you only need one of them, at approx AUS$1500.

So 50% more on price, but one sixth of the weight and one third of the real estate. [300L X 170D X 220H in mm, for one *typical* battery]

I know this is an *imperfect comparison* because there are additional costs with the lithium batteries, like Battery Control Units, and External Relays that can add a few hundred extra.

But if your 4 lead acids last only three years, then to match the lifecycle of the single lithium battery you would need at least 5 lots of batteries, or around AUS$4000.

So over time, the lithium battery wins on cost.

Even if the total cost were the same (and it's not, $3100 buys a 400Ah lithium pack from EV Power - 4 times the size of what we're talking about) the lithium would still win on compact size and weight - for our *cruising displacement* exercise.

Of course, you can buy a LOT of ice with $1500 bucks.....

Just sayin'.....

[Cavalier MK2]

You guys should take a peak at the global market for lithium batteries. Currently the production is maxed out making life more challenging for companies such as Tesla who have sold a 5% share to the Chinese who are currently producing most of these whiz bangs. This week Volvo cars, now owned by Chinese interests has announced that all of their future production will be in hybrid and all electric vehicles. So.... it would stand to reason that products with ties to the home plate will be getting first whack at the contemporary battery solution. Sounds like prices could rise or availability could suffer.

Buzzman, I get a decent 6 years at least out of a conventional battery but you are right, I don't use them much.

i like green solutions but they come with a hefty premium and I often find I'm much greener by doing without.

[Buzzman]

Hmmm....as Tesla is about to bring on-stream HUGE lithium battery making facility in Nevada, called a Gigafactory becasue it will be producing gigawatts of batteries, I think it's unlikely production will slow.

Most EV/alt.energy pundits are in fact predicting a further decrease in the price of lithium batteries, possibly by as much as 50%, over the next several years.

As govt-funded rollouts of solar PV expire, many homeowners (like here in Oz) will be looking to add batteries for storage to regain the loss from the rmeoval of subsidies, further ramping demand.

Availability will increase, supply will increase, and prices will fall due to increases in production and economies of scale.

But you're right, going green can be costly.

My 2kW rooftop PV installed 7 years ago for AUS$4700 would today only cost $3600 according to the latest el cheapo offer that popped into my Inbox.

But a 7kWh battery from Tesla is still quoted at around AUS$7-10K, which is beyond my reach at present.

But if elec price doubles as pundits here are forecasting, it will start to look tempting....

[Cavalier MK2]

For sure we'll see. When the price starts to average out the lithiums will be more tempting but to put it in perspective I'm getting 6 years out of something that cost $50. There is also increased fire risk with these things which is a lot more scary than running out of juice on the water. Tesla also had to make that plant to try and supply their anticipated production which means no change in the supply chain for other channels.

I think getting houses off the grid by using good electrical storage and solar shingles is commendable but it is out of the reach of many at the present.

[Buzzman]

As I understand it from what Tesla has stated (and that's a set of moving goal posts...) the Nevada factory is primarily for making Powerwalls and car batteries, which they currently get from China.

Alas for our sins, but batteries are *MUCH* cheaper in North America.

Even the most basic starting battery for a small four-cylinder car costs around $100 minimum.

As I said previously, the price for a Century N70T 100Ah deep-cycle battery, ideal for marin or RV 'house' battery, is $250, and that's from a major discount store, not RRP.

And the South Pacific Peso (aka the Oz $$) is only buying about US$0.75c at the moment. Do the math yourself.

Going off grid is only a cost-effective option at present if you are installing power for the first time and distance from the grid adds cost of power poles and necessary cabling into the mix. Currently it's about AUS$90,000 per km.

So if you are more than one or two hundred metres off the grid you're probably better of going "off grid" as that will only cost about half the amount for poles and wires for solar PV and battery storage.

Firms here offer "in a container" solutions that are plug and play for around $50K

But remaining connected to the grid, and feeding back excess PV-generated power is much cheaper.

As I said previously, only $4700 for me to connect to the grid.

As the govt-funded subsidy I was on (60c/kWh) has now ended, and I'm back on the *wholesale* rate of 10c/kWh for any exports, I have converted my meters to "nett" export, so I can use power direct from the PV panels (via my built in inverter) while the sun shines, then take from the grid at night.

I have calculated that a 7kWh battery would enable me to effectively be self-contained and not need power from the grid, but might still enable me to export some excess not used/stored/used.

But as I said, that battery will be somewhere between $7-10K, which bys a lot of power, even at the rate of 30c/kWh we are paying at present.

But if that doubles, as some pundits here are suggesting, to 60c/kWh, then it begins to look more attractive.

Much cheaper to power a boat.....

[owly]

I've included a chart showing depth of discharge for lead acid batteries versus cycles. If you do the math, you will find that instead of using 4 deep cycle batteries weighing in at 100 lbs each and running them in the top 20%, you can use ONE of those batteries, and allow it to discharge 80%. The cost penalty is small. It means replacing a battery about every 9- 10 months, rather than 4 every 4 years. Of course if you are in the US, Batteries Plus offers a 12 month free replacement warranty on golf cart batteries, and my math says that 10 months is less than 12 months

Simple math shows that your "cost premium" if you use a single battery and discharge it down to 20% charge, is 22%, over using 4 batteries and discharging them down to 80% charge.... assuming you pay full freight and don't get battery warranty. That 22% is rolled into a small annual battery replacement cost, instead of getting hit with a large expense when you have to replace all four batteries of a larger bank.

If you are in the US, and can benefit from free replacement, it's a win win situation....... A one time investment, and free batteries from then on, and a 300 pound weight reduction.

The up front cost of lithium batteries is pretty high, but the lifetime cost is probably lower. But there is also the issue of charge control & temp control, etc. I'm far from convinced that Lithium batteries are a "mature technology" for marine use, and NOT from lack of experience with lithium batteries.

In any case the process should begin with an energy audit. What am I using electricity for and how much. The key is to reduce these needs wherever possible, and to AVOID BATTERY USE wherever possible. Hence my refrigeration scheme, which does NOT use battery power. Every watt hour in and out of the battery has a cost. Lighting and electronics, are the next conservation target. LED area lighting, and specific "personal lighting" wherever practical. Good LED running lights are available if not cheap. No electric pumps, mascerators, etc. Composting system for coastal waters, "direct deposit", at sea. Radio(s) shut off except when needed, and of course as I mentioned before..... manual watermaker. Cut the storage needs to a minimum to keep battery weight and cost to a minimum.

H.W.

[Cavalier MK2]

Tesla is going to help our friends in OZ with BIG batteries. Tesla to build world's largest lithium ion battery in Australia - BBC News

[Jimske]

Originally Posted by Cavalier MK2

You do need length to carry load, mid 30' you are starting to get enough for reasonable hops. Jim Brown felt the 31 was too small for 4 on long crossings with his own family. The Nicol has a fairly beamy main hull but is more fun light. I tell people we can day sail a dozen. Coastal cruise 4 and long haul 2-3 with the gear and supplies to be comfortable and fun. Those numbers can be added to but then you are cutting into the fun.

Agreed. These days the 31er is best for some longer coastal cruising with up to 3 adults and without heavy gear. 4 adults for some island hopping.

OTH, a couple could do liveaboard and cruise IF they were minimalists. I keep all kinds of tools and spare parts as well as paint, epoxy, etc. on mine and still travel very light with LOTS of places that are basically empty.

J

[Jimske]

Originally Posted by UNCIVILIZED

Thanks guys. Little that I don't already practice, & have since I was a kid. And, yeah, the "serving sizes" on those freeze dried meals is laughable.

Anybody enjoy Indian Cuisine? ethnic

I buy this stuff at a local discount store. Each meal is 2 bucks (used to be $1.50 - growl) and weighs about 6 oz. Mix with some rice and you got a decent portion meal or eat 2. So for each person that's about 20 lbs for dinner meals for a month. So if you could duplicate that for breakfast and lunch (different food of course) each person could get by with 60 lbs for the month - supplement with fish and pig out when you hit shore!

When passage making one is trying to end up at a port somewhere. Seems reasonable to be frugal with stores while getting there. But that's just me.

J

[Jimske]

Originally Posted by owly

the real benefit would be never needing to fill up with local water, and worry about it's quality or endure the chemicals. I have drank my own well water, innocent of any filtration or chemicals for over 30 years. High quality from an aquifer fed directly from the nearby mountains, it doesn't even lime a coffee pot. Drinking city water laced with chlorine and floride, picked up out of a river with the sewage from cities upstream, would quickly turn me into an alcoholic!! Cervesa rapido!! H.W.

Now I'm convinced. Need a water maker!

[Cavalier MK2]

My Nicol figures are conservative because the key words are comfortable and fun. Which means not having to weigh things to the last ounce. If I load for a month for 2, I'll provision for 2 weeks for 4 or a week and a half for 6 but as you add people there isn't the room to take all the extras for everybody.

For a solo cruiser a 31 would let you bring whatever you want.

Hiking is a great activity because you don't need extra gear but if the trip was a biking then person 5 gets kicked off for room for the extra folders. Or perhaps kayaking would be better so a couple doubles as deck cargo and the bikes stay home etc....

There are plenty of ways to save some weight. The LED lights Owly mentioned should be battery powered. Efficiency lets them run on AAAs for a long time and that cabin lighting wiring can be tossed etc.... I know propane is popular but dang, all that stuff adds up fast. Same with tanks versus water bottles, they need plumbing and vents plus can drain out if you invert and forgot to install a check valve.

[owly]

Let's see it it works this time ;-(

H.W.

[owly]

Originally Posted by Cavalier MK2

My Nicol figures are conservative because the key words are comfortable and fun. Which means not having to weigh things to the last ounce. If I load for a month for 2, I'll provision for 2 weeks for 4 or a week and a half for 6 but as you add people there isn't the room to take all the extras for everybody.

For a solo cruiser a 31 would let you bring whatever you want.

Hiking is a great activity because you don't need extra gear but if the trip was a biking then person 5 gets kicked off for room for the extra folders. Or perhaps kayaking would be better so a couple doubles as deck cargo and the bikes stay home etc....

There are plenty of ways to save some weight. The LED lights Owly mentioned should be battery powered. Efficiency lets them run on AAAs for a long time and that cabin lighting wiring can be tossed etc.... I know propane is popular but dang, all that stuff adds up fast. Same with tanks versus water bottles, they need plumbing and vents plus can drain out if you invert and forgot to install a check valve.

Propane weight including the tank is double the actual fuel weight typically. Alternatives are limited. Personally I like Coleman Fuel or "white gas"........ I haven 't seen the latter since the mid 70's. Unleaded is NOT the same thing, however ordinary "mo gas" can be distilled rather easily. I once did it years ago, outraged about the cost of Coleman Fuel........ which is naphlene mostly. Naptha is a common thinner which is available in many places where they sell paint. Container weight is a non issue as it is a liquid. I mentioned this earlier.
I'm interested in dehydrated water......... it weighs nothing at all..... just add water to reconstitute. Much lighter than carrying water in it's liquid form I'm told

H.W.