Electrical resiliency for Atlantic crossing

[Pegu Club]

If you have space, add another solar panel, maybe a wind generator as well. You will be very happy if you add the Monitor steering vane, we have had ours for about a year now, great piece of kit. Scanmar as well makes an autopilot that can be attached to the Monitor that is very low amp use. You can as well use it as an emergency rudder with the attachment Scanmar has for it.

Fair winds,

[noelex 77]

Originally Posted by Mediator

With normal sunlight, we will deplete our battery bank in about 5 days if we don't run the engine on a passage.

This really answers your own question. Without the engine your solar production is not keeping up with demand. Given you have a 985AHr battery bank, this also suggests the shortfall is reasonably high. For example, if you are referring to the batteries reaching 50% , it indicates you are consuming over 100Ahrs a day more than your typical solar output.

If you want to undertake a long passage your production must equal, or at least very nearly equal your demand on average. A large battery bank can be used to even out good and bad solar days, but it barely adds anything to the average amount that can be consumed over the length of an Atlantic crossing.

I think your aim of producing enough power to be independent of the main engine output is a reasonable goal, although if the engine is unreliable this issue should be adressed for many reasons.

So to reach this goal you need to increase production and/or decrease demand and the change needs to be reasonably substantial.

350W of solar should be just enough to meet your requirements, but this assumes efficient equipment, especially the high draw appliances such as the freezer, fridge, autopilot and instumentation (charplotter etc). Lighting needs to be LED etc etc. On the production side the solar panels also need to be well installed with a reasonably shade free location.

The other alternative is to produce more power with additional solar panels, a wind generator, hydogenerator or portable petrol generator etc etc. There are many options and it is difficult to recommend the best solution without knowing you boat, budget etc.

My recommendation would to be first to look at reducing your demand and optimising your current system. Many boats with 350w solar can manage independently in reasonable solar conditions without engine input, although doing so with a freezer is more difficult.

[mikedefieslife]

Originally Posted by steve77

Well, here are some thoughts...



I don't know what "1kw of battery capacity" is. Capacity is usually listed in Amp-hours or it could be Watt-hours. Can you please check this and give us some more information?



As already stated, you need an energy budget so we can help with specifics. I believe you will find that your heaviest electrical load will be when you are underway. This is because of loads that are only turned on underway such as nav lights, VHF, chart plotter, radar, etc. Just looking at it though, with a fridge and a freezer, it does appear that the 350 Watts of solar will not keep your batteries full and you need to have some other means of charging.



We crossed the Atlantic in 2014 and have been in the Med since. If you are coming to the Med, then you need to have your engine absolutely reliable. The winds here are fluky and you will spend more time motoring than you expect. I met one sailor in Mallorca who was on his way back to the US in September. He had just arrived in the Med that spring, but he was so frustrated with the lack of sailing conditions that he was going back after only one summer in Europe. In short, I think you need a reliable engine.



I would put a Balmar or some other brand good alternator on it with a regulator. This will be your backup for charging your batteries. I would not put on a second alternator. For your redundancy just keep your existing alternator on board as a spare. Each boat and each crossing is different, but on the northern route we enjoyed a hot shower once in a while. I do know we motored twice - 7 hours once and over 36 hours another time.



On Orontes II we have 540 Watts of Solar with our 900 Amp-hour battery bank and could sail indefinitely with that installation, given good sun. We do have a wind vane, which reduces load considerably.



I also have an installed genset, which is a third means of charging batteries. Some people have a Honda generator for this purpose. There are some real concerns with going this route (search on old posts) but it would give you another way to charge batteries.



Cheers!



Steve

For the price of a balmar though he could get a used honda suitcase gen or a new one of a lesser brand. It could then be sold after the trip.

[a64pilot]

Originally Posted by mikedefieslife

For the price of a balmar though he could get a used honda suitcase gen or a new one of a lesser brand. It could then be sold after the trip.

I think for a lot less price, an alternator needs of course a way to mount it as it’s a second alt, and needs a belt and of course a controller.
A little Honda needs nothing but a can of gas and as you say can easily be sold if you decide you don’t want it anymore.

But the issue is he is concerned about engine reliability, not the reliability of the existing alternator, so a second alt does nothing to fix that.
Depending on what’s the issue with the engine, it could be an easy fix or require a repower. If I were to guess, I’d guess it’s just old and has a history of different problems over the years of one system and then another breaking down

[Snore]

Originally Posted by mikedefieslife

For the price of a balmar though he could get a used honda suitcase gen or a new one of a lesser brand. It could then be sold after the trip.

Agreed.... Although, I have posted many times that a portable generator does not belong on a boat because of the probability of CO poisoning. Having just delivered a boat Boston>Gibraltar with one that was purchased to offset the untimely death of the vessels diesel generator, my opinion is reaffirmed. Portables really don’t belong on board. BUT, it is more fuel efficient to run the smaller gen than the main engine. Also, most voltage regulators taper the charge rate after 20 minutes.

Therefore, a good battery charger driven by a generator provides resiliency that is not dependent on the sun. The trick is locating the portable such that the exhaust stays out of the cabin. In our case it required some socks in the dorados.

Whatever your final plan is, do a one week trip and see if your plan is feasible. Do you have crew that can hand steer for hours on end during the day? Can they do it day after day? Will your solar really bring the batteries back up? Where can you store the portable so it is safe (not on deck) and where can you place it not to have CO issues?

Finally, consider adding insulation to the freezer.

[KTP]

CO detectors (we have two) will go off somewhere around 50ppm to 150ppm but definitely at 400ppm within a few minutes. If you have these with good batteries plus you close off the dorados and windows while you are running the generator on the foredeck, I would hope you would be ok.

[barnakiel]

A sailing boat does not require electricity to cross an ocean. Actually I have prepared for such an emergency and always carry a pack of old school razor blades.


On the N route you will do fine with a fine powerful wind turbine. With a sound engine and the alternator connected to a proper three stage regulator and some healthy batteries you are all set. Solar panels are fine if not at their top performance on this route.


Just keep things simple and make sure you have more than one option to charge the batteries.


Electricity is nice to have but not something one cannot sail without. MEANWHILE A BEST WIND VANE YOU CAN AFFORD is a truly best companion in any long ocean adventure. !!!



Enjoy the passage.



Cheers,
b

[KTP]

Originally Posted by barnakiel

A sailing boat does not require electricity to cross an ocean. Actually I have prepared for such an emergency and always carry a pack of old school razor blades.
b

Coffee however, is required. If you run out of coffee, you better have the razor blades.

[scallowayuk]

hi, i have been cruising for the last 20 years 8 atlantic crossings,i have never had more than 110 amps of leisure battery or 40 watt solar panel.ive never had a flat battery except when needing replacing. all my lights are led i have a wind vane to steer and a small autohelm for when theres no wind.but no freezer.thats what uses power. and car radios.most other boat electrics use very little power.and no inverter 12 volt chargers for everything including the laptop.

[mikedefieslife]

Originally Posted by Snore

Agreed.... Although, I have posted many times that a portable generator does not belong on a boat because of the probability of CO poisoning. Having just delivered a boat Boston>Gibraltar with one that was purchased to offset the untimely death of the vessels diesel generator, my opinion is reaffirmed. Portables really don’t belong on board. BUT, it is more fuel efficient to run the smaller gen than the main engine. Also, most voltage regulators taper the charge rate after 20 minutes.

Therefore, a good battery charger driven by a generator provides resiliency that is not dependent on the sun. The trick is locating the portable such that the exhaust stays out of the cabin. In our case it required some socks in the dorados.

Whatever your final plan is, do a one week trip and see if your plan is feasible. Do you have crew that can hand steer for hours on end during the day? Can they do it day after day? Will your solar really bring the batteries back up? Where can you store the portable so it is safe (not on deck) and where can you place it not to have CO issues?

Finally, consider adding insulation to the freezer.

I can't see how you are any more likely to get c02 poisoning than when running your engine, using an outboard, running a diesel heater, or riding a moped. Obviously you don't run it inside the boat.

[barnakiel]

Originally Posted by KTP

Coffee however, is required. If you run out of coffee, you better have the razor blades.

Indeed. And interestingly:


https://en.wikipedia.org/wiki/List_o...inks#Cold_brew


Note that we can make do without electricity and also without a stove!


I have not tried the above yet. Have you?


barnakiel

[barnakiel]

In more practical terms:


Our own (small boat) is power independent for 2 days - under FULL load.


Our full load situation is:


- nav lights at night,
- gps (puck) / vhf (Rx) / ais (Rx)
- basic interior lights at stove and bunks.


After 48hrs without charge, we are at 50% home bank charge (engine bank 100%).


If we switch off gps / vhf / ais, we can go on for 10 days.


If we switch off everything and use gps for positioning only, we can go for about 300 days.


So ... I guess what I am trying to say is that resilience will depend on appetite.


Our charging kit is alt on the engine and solar panels. The panels can charge the batts in full in 2 sun-days = about 10 overcast days.


On an average passage day we are back at 100% by 14:00 sun-time.



In fewer words, in our case, the resiliency is MINIMUM 2 days.


Crossed N Atlantic 3 times, S Atlantic 5 times, Pacific, Indian, etc. Wind vane, no fridges, no aircon.


ymwv




Cheers,
b.

[stormalong]

Originally Posted by conachair

Going long distance cruising they will die

When they do it happens quickly.

And if you're unlucky it might be a very long way to find some decent new ones.

In 19 years and 130,000 mile of cruising I have never had total battery failure.

Batteries do not fail quickly. They fail over time with lots of warning. Watch your batteries like a hawk. Observe the voltage drop between charges. When the voltage drops to unacceptable levels faster that you have seen in the past it is time for a new set of batteries.

Freezers draw a huge amount of power. Learn to live without it.

Take note that 1000 AH of batteries should only be discharged 500 AH MAXIMUM. A good battery monitor is essential. Watching both battery voltage and AH usage will give you a very good picture of what is happening with your batteries.

Accept the fact that heavily used batteries will only last a few years. Shallow discharging (keeping them full) will lengthen their lives.

[CassidyNZ]

Originally Posted by barnakiel

A sailing boat does not require electricity to cross an ocean. Actually I have prepared for such an emergency and always carry a pack of old school razor blades.

Maybe not to to cross an ocean but if you have no electricity to start your engine, you would in many cases have severe constraints entering ports and harbours. A perfect example is getting into Nuku Hiva which has a headland on one side that more often than not kills the wind when you’re sailing in and a significant current setting across the entrance directly onto the rocks under the headland. Don’t ask me how I know this.

Perhaps the old school razor blades are to use on your wrists just before you hit the rocks?

Originally Posted by barnakiel

Electricity is nice to have but not something one cannot sail without. MEANWHILE A BEST WIND VANE YOU CAN AFFORD is a truly best companion in any long ocean adventure. !!!

My only experience with a windvane was an old Aries many years ago, when auto pilots were still “white man’s magic”. It worked OK until running off the wind when they’re known to be not so great. And given that most of my cruising is done off the wind, a new one for my boat languishes at the very bottom of my wish list.

As above, an ocean crossing is about a lot more than sailing from one place to another. The number of systems on a modern yacht that depend on electricity are what make the difference between cruising and surviving. Personally I prefer to cruise and for this, at least on my boat, electricity is essential.

[hzcruiser]

Originally Posted by Mediator

Our engine has a mount for a second alternator that was clearly utilized at some point, which is why I'm tempted by the idea. It seems like an easy modification.

Sounds like it's time for me to create a real energy budget.

More solar might not be a bad option. We certainly have the space for it.

All good ideas there! Also, you might want to create a separate thread to discuss your engine reliability, since a diesel engine should be just that.