Bestevaer 49

[MikeBz]

This thread is a fascinating read. Thanks for sharing your insights and giving us food for thought.

Absolutely. I'm fascinated by the amount of forethought that can be put in to these things when starting with a blank sheet of paper. I can sit and stare at a blank sheet of paper for days on end and still not know where to start. Another one I enjoyed reading was this: http://www.petersmith.net.nz/about/kiwiroa.php

 

[noelex]

Battery Monitor: Simarine Pico.

If you are an electronics geek (like me) you are going to love this device.

The battery monitor functions in an unusual way, but there will be more about that in another post. First I wanted to outline its capabilities. It will do things no other battery monitor will do. Here is a brief list (bear in mind some of these options require additional shunts etc):

Monitor 6 battery banks
Display current information (such as solar panel input, fridge output etc etc) from 24 different shunts.
Display temperature information from 10 different locations
Display information from 6 tank level sensors
Display atmospheric pressure (including a nice graph)

These inputs can all be individually named and are displayed in digital format, as well as an analogue bar graph that can be tailored for the individual input. So the analogue display will show full deflection at the maximum expected value. There is also adjustable minimum and maximum alarms that can set for most parameters as well as data logging and calibration for many inputs. The data can also be sent via wifi and displayed on a tablet or smartphone.

I cannot imagine anyone will be using all these options, but my planned installation might give some impression of how this might work practice, although initially not all the capabilities listed below will be installed.

The main home page will display:
House battery voltage
House battery SOC
Net current into or out of the house battery
Solar panel input for each of the three solar panels
Fridge current output

Further pages will display:
Start battery voltage
12v system voltage
Barograph (in graph form)
Temperature:
It would be easy to go overboard here but I can see the following as potentially useful:
Air
Water
Battery
Fridge
Engine
Engine exhaust
Engine alternator
Some of the above would befit from alarms, which are easy to set.

Other options include monitoring the alternator output although this will require the purchase of an additional shunt.

So how does it perform?
I have only set it up on test bench so far so a detailed performance review will have to wait, but the initial impression is very favourable. The display, while small, is gorgeous and the software is excellent, enabling extensive customisation while keeping things relatively simple.

The battery voltage is shown to 2 decimal places (much better than one) and the reading is spot on. Many battery monitors get even this simple but important measurement wrong. Errors of around 0.1v or more are not uncommon.

Shunts of 500A (and more) are available which can be important for larger boats.

Drawbacks:
It is expensive. There are also so many capabilities that it is tempting to make the installation complex. There needs to be some thought whether the information will be useful rather than just cool to have.

The main question is how it performs as battery monitor. I talked to the developer at the Dusseldorf boat show several months ago and he is a very smart guy who understands battery technology and what is needed to design a good battery monitor. The monitor is sophisticated and works in a slightly different way to most other battery monitors (more about this in a future post). It will be interesting to see how this translates in practice.

 

[noelex]

A bit of background on battery monitors may help put the Pico into perspective.

There are two quite different approaches to producing a battery monitor.

The first monitors battery voltage and importantly the current going into (or out of the battery). In the simplest form this type of monitor counts the amp hours going into and out of the battery and uses this to display the net amp hours that have been drawn from the battery. If you enter the battery size it can also estimate the net state of charge in percentage terms. The better models are more sophisticated and take into account Peukert's law which simply means the battery capacity diminishes more rapidly than might be expected when there is a high current draw relative to the battery size. They also take into account battery efficiency (not all of the current entering the battery is converted into capacity. Unfortunately, this changes with voltage). A small number of the better models also use battery temperature as this effects battery capacity. As even a sophisticated counter will gradually drift out of synchronisation over many cycles, there also needs to some means of automatically zeroing the meter, usually when the monitor recognises that the battery is fully charged. How this is done varies.

The above brief explanation shows this type of meter is complex, and not all models are equally good. In my view, the better models are accurate, but they need to be set up well both physically with the correct wiring, and you need to enter battery details such as the nominal capacity and the particular Peukert's exponent of your battery type. Unfortunately, it is rare to see one set up correctly.

The second type of battery monitor works in a very different way. It does not measure current or temperature only voltage. Wiring is simple and there is no need to enter many details about the battery. Exactly how these monitors can convert simple voltage information into a meaningful display of the state of charge is never fully explained by the manufacturers, for obvious reasons. There are several possible mechanisms that could be used, and it is important to realise that these are not simple voltage displays, but devices using complex algorithms to determine the state of charge. The main advantage is that they are very simple to install and use. They take some time to "learn" any particular battery installation, but the manufacturers point out this only means the accuracy of the reading is constantly improving. The biggest drawback is there is no current display, which is unfortunate as this is very useful information in its own right. The most popular model that works in this manner is the SmartGauge.

Both these very different types monitors often have very adamant supporters.

The obvious question is why not combine these different approaches in a single monitor? This has the potential of producing the most accurate battery monitor and overcoming some of the limitations of both approaches.

Surprisingly no one, to my knowledge, has previously combined these two methodologies. A couple of companies have hinted their products incorporate some "special" technology, which makes them different from conventional amp hour counting monitors, but I suspect most of this is advertising blurb.

The Pico is a little different. It has what appears to be a very sophisticated conventional amp hour counting technology, but will also work as a battery monitor with no shunt attached at all. You would be silly not to use a shunt and Simarine point out if the monitor is used in this way the results will be less accurate, but the fact that it works at all indicates it is also capable of monitoring the battery state of charge using the second methodology. Simarine also point out their monitor works better as it "learns" the battery system, once again indicating the monitor is using elements of the second approach. Intriguing.

A battery monitor that uses both methodologies, the best of both worlds?

Perhaps this is the answer to settling those forum threads on battery monitors that can sometimes become a little too passionate?

Anyway, at this stage I have been very impressed with the monitor, but a propper evaluation will take some time. As I use the equipment more it might also be clearer exactly how the battery algorithms function so take the above comments as provisional rather than definitive.

Also keep in mind you can still monitor batteries with a simple dumb voltmeter. This method has some limitations, but is by far the cheapest option. If you have a simple electrical system it is an option worth considering.

 

[NormanS]

I expect that you are going to use waste heat from the engine(s) to heat domestic water, but are you planning to use it for space heating when available?

 

[noelex]

are you planning to use it for space heating when available?

A good question. A "bus" (or large car) cabin heater fed from waste engine heat has been recommended by a couple of very sensible cruisers whose opinion I respect (thanks Dockhead and Panope), but this advice was a little too late to incorporate into the original build.

It is an an option that fortunately in our case would be easy to retrofit, but I think we will sample cold water cruising (our previous adventures have been in warmer waters) before we decide if this is worthwhile.

In the mean time we have a Refleks heater that will be installed in the new boat. These are a well regarded Danish diesel fed drip heater. They consume no power (unlike air heaters). They are very simple and apparently very reliable, but while many of our equipment decisions have been influenced by our previous personal experiences, following many years full time cruising, we have had little contact with boat heating. This is where advice from other cruisers and forums like this can be so valuable. So thanks for the post.

We saw our Refleks for the first time today as KM are starting the installation. I will take some photos showing the set up in the near future.

 

[NormanS]

The reason that I asked is that several years ago, I retrofitted that type of heating in my 36ft Deck Saloon ketch. I sail in the NW of Scotland, and obviously while it's no use when sailing, if motoring from inside, on a cold wet day, it is worth its weight in gold. I used a heater matrix from a Ford Transit, a 3" in-line blower fan, and a bit of ducting.

I always think it strange, that while every motor vehicle has a heater, so few even high spec boats have them, and just let all that valuable energy go to waste. It depends of course, on the waters that one sails in.

 

[npf1]

noelex, I'm curious to know the plan for the exterior (coachroof sides/topsides etc). Totally bare, or some paint, or some vinyl like Pure? And for the deck?

 

[noelex]

I always think it strange, that while every motor vehicle has a heater, so few even high spec boats have them, and just let all that valuable energy go to waste. It depends of course, on the waters that one sails in.

Yes, good point.

 

[noelex]

noelex, I'm curious to know the plan for the exterior (coachroof sides/topsides etc). Totally bare, or some paint, or some vinyl like Pure? And for the deck?

The biggest drawback of aluminium as a boatbuilding material is that paint does not stick well. On the plus side, raw marine grade aluminium does not need any protective covering even in salt water.

Therefore our plan is to keep the areas of paint to a minimum. The paint will basically only be on the horizontal surfaces (apart from the antifouling) and even here around all the fittings and corners there is broad gap before the paint starts.

We have found that repainting aluminium on flat areas, especially non skid zones where the texture hides any subtle flaws, is very quick and easy. Aluminium is tough so a sanding disc makes short work of removing any old paint without damaging the underlying surface. What is very time consuming is removing any loose paint from around corners and over welds, for example on the joint between the deck and bulwark. Much of this needs to be done with hand sanding.

So by leaving off paint in this areas refinishing is easy.

The vinyl solution is a good one that I think will keep looking nice for longer with no treatment, but it is not possible to repair any defects without ordering new vinyl from specialised companies. The advantage of paint is that you don't have to be concerned about for example dropping something heavy on deck. The paint can be touched up in a few minutes and a proper repaint done when the panel starts looking shabby.

 

[npf1]

If you like the vinyl, have you contemplated something 'stick on' for the horizontal surfaces? One I like is (and will soon be my boat) Grapetread – GTSB http://www.grapefruitgraphics.co.uk/services/cockpit-deck-grip

 

[noelex]

The bellcranks for the autopilot drives are in the process of being fitted.

The lazarette is very large. We have found there is a need for lots of storage that is out of the main cabin area. In here you can store things like diving gear, fenders etc. This is gear that needs some protection on a cruising boat, but you don't necessarily want to store this type of equipment in the main living areas.

The finish has been left bare aluminium with an aluminium tread plate floor.

 

[prv]

Nice :encouragement:

Looks somewhat reminiscent of a Dashew FPB (I suppose that would apply to the inside of any substantial aluminium boat)

What's the gas-strut just aft of the stock for? I would assume it holds open a locker lid except that I can't see how that would fit in that position.

Pete

 

[noelex]

Well observed Pete.

The strut is to assist with the raising/loweing of the rear transom that folds down to open up the back and become a swim plarform.

 

[Kelpie]

I take it that flexible collar is to contain any water ingress should there be rudder problems? Or is it simply to keep dirt out of a bearing? Looks neat; I wonder what lifespan you can expect from it?

 

[westhinder]

If you are going to use the lazarette for stowage, I take it you are going to put a protection or a cover around the steering mechanism? Otherwise something might get shifted by the waves and damage or block the steering. We have such a cover and I would not feel at ease without. Plenty of things in the lazarette that could go walkabout when you least want it.

 

[noelex]

I take it that flexible collar is to contain any water ingress should there be rudder problems? Or is it simply to keep dirt out of a bearing? Looks neat; I wonder what lifespan you can expect from it?

The top of rudder tube is above the waterline, but Jafa recommend the gator for the reasons you mention.

If any water enters the lazarette through, for example rudder damage, there is a waterproof bulkhead forward of this, so no water enters the main part of the boat. There is also a waterproof bulkhead behind the sail locker in the front of the boat so the bow thruster and transducers are also isolated. The middle of the boat is divided by another full height waterproof bulkhead and waterproof door.

This divides the boat into 4 watertight areas (5 if you include the engine bay).

 

[Zing]

If any water enters the lazarette through, for example rudder damage, there is a waterproof bulkhead forward of this, so no water enters the main part of the boat. There is also a waterproof bulkhead behind the sail locker in the front of the boat so the bow thruster and transducers are also isolated. The middle of the boat is divided by another full height waterproof bulkhead and waterproof door.

This devides the boat into 4 watertight areas (5 if you include the engine bay).

Would you be unsinkable from the breach of any one zone?

 

[noelex]

If you are going to use the lazarette for stowage, I take it you are going to put a protection or a cover around the steering mechanism? Otherwise something might get shifted by the waves and damage or block the steering. We have such a cover and I would not feel at ease without. Plenty of things in the lazarette that could go walkabout when you least want it.

Yes, good point. One major advantage of a tiller is that the steering system is bulletproof, so it would be a shame to compromise this. The lazarette extends forward from the steering system by a meter and half so there is plenty of room for storage while leaving the steering system free. The bare aluminium ribs and stringers provide plenty of tie down points.

We have made an effort to make sure everthing is well secured down on the boat. For example, all the locker lids, even those under the settees and bed have catches so they cannot become loose, or spill their contents in the event of a knockdown. All floorboards are screwed down, (these can still be lifted if inspection is needed) or have quicklock catches. The washboards cannot slide out etc etc.

If you have an opportunity, take a look at the Yachting Monthly videos of the interior of a typical yacht when it is inverted. It is easy see to how serious injury could occur from flying objects, even with just a knockdown.

Here is a link:
https://youtu.be/Gqe1Sxa2GXo

 

[noelex]

Would you be unsinkable from the breach of any one zone?

Yes, the boat will still have plenty of positive bouyancy if this occurs.

 

[noelex]

The new oven has just been installed.