Leaving boat for winter, what to do with solar, water and diesel etc

[Peter]

Will be leaving out boat, out of the water, in northern Spain for 8 months over the winter. My questions are how to winterise to boat with respect to.
Got 400W solar with MPPT controller. Leave to charge batteries. But I was thinking to disconnect or cover one to reduce Wattage as I feel having 400W available seems a bit overkill just to charge batteries, 550amp/hr.
Water tanks, leave full or empty
Diesel, will follow current advice already seen and leave full if I can get to pump
Flush engine sea water circuit through with fresh water
Toilets, Jabsco, flush through with fresh water and cleaner

Anything thing else I should do or any other advice

 

[duncan99210]

Solar: let well alone. The controller will protect the batteries from overcharging so don't bother to do anything to the set up that you'll need to reverse in the spring. Our panels are directly connected to the batteries so I also turn off the main isolator so that nothing can be accidentally left switched on as a drain on the system.
Diesel: fill the tank if possible. I usually refill as we pass the last fuel berth but then have a day or three at anchor before lift out, so th tank is never absolutely full but close enough.
Water: we empty the tanks before leaving the boat on the hard. Just feels like the right thing to do.
Engine: service before lifting and that's it. Ours is indirectly cooled, so the sea water is only in the heat exchanger circuit and I wouldn't bother flushing it through. Different perhaps if you have a directly cooled engine where corrosion could be a problem.
Heads: pump through to get rid of sea water. Don't flush with fresh water, too much like hard work.
We block all the holes in the hull (sea cocks, exhaust, vents etc) with sponges to prevent wasps and other insects setting up home.
Drop the chain onto a pallet along with the anchor so that the rain washes it through. We always drop the complete chain so as to deny rats an easy access route, other use rat guards to stop the little dears as they don't drop the end of the chain.
We've been leaving the boat like this for some years now and never had a problem so far.....

 

[GHA]

Good article here regarding leaving the batteries, comes out very much in favour of leaving then disconnected..

http://www.pbase.com/mainecruising/self_discharge

 

[Mee]

Good article here regarding leaving the batteries, comes out very much in favour of leaving then disconnected..

http://www.pbase.com/mainecruising/self_discharge

In the article it says, "Contrary to popular misconception cold weather is actually not a bad thing for the batteries" - quite true, it's actually the hot weather that kills them, but you only notice in winter because the power needed to start a cold car/boat is greatly increased in cold weather

 

[lw395]

I don't think I'd fill the diesel. If possible I'd check the bottom of the tank for water.
How much diesel? What are the tanks made of?
As the tank won't be sealed, I would rather have fresh diesel next year.
Maybe store what you have in sealed plastic cans or give it away?
The batteries I'd want a float charge. Even a fraction of that wattage means you need to trust the regulator.
8 months is a long time.

 

[johnalison]

I don't think I'd fill the diesel. If possible I'd check the bottom of the tank for water.
How much diesel? What are the tanks made of?
As the tank won't be sealed, I would rather have fresh diesel next year.
Maybe store what you have in sealed plastic cans or give it away?
The batteries I'd want a float charge. Even a fraction of that wattage means you need to trust the regulator.
8 months is a long time.

Conventional wisdom is that if you leave a lot of space in the fuel tank, the changes in temperature will cause the air within to expand and contract regularly. As moist air is sucked in the water content will condense, the air will expand again before drawing more moist air in and so on. I once read of a neat solution which involved putting a balloon over the vent, but have not seen this in use.

 

[lw395]

Conventional wisdom is that if you leave a lot of space in the fuel tank, the changes in temperature will cause the air within to expand and contract regularly. As moist air is sucked in the water content will condense, the air will expand again before drawing more moist air in and so on. I once read of a neat solution which involved putting a balloon over the vent, but have not seen this in use.

I'm aware of the conventional wisdom.
I don't rate it highly.
I think somebody busted this bit of folklore a while back.
Might still be valid if you have a mild steel tank though.

Diesel has changed.
8 months in a vented container is a long time.

I'm told the balloon trick probably won't go well as the vapour from the diesel will attack the rubber.
If the tanks can stand the pressure, a vent valve which only lets air 'in' is commonly fitted to the vent of motorbike tanks.
One might want to remove it before trying to refill the tank or it will throw fuel back at you.

 

[Pavalijo]

Solar: let well alone. The controller will protect the batteries from overcharging .....

I am pleased this has been raised as I have been pondering how to leave our 240w solar panels and batteries overwinter. They charge batteries via an MPPT controller but I did wonder if there may be an issue with the controller allowing a period of bulk charge each morning as the sun rises, overcharging already full batteries?
The advice I got from Barden was to connect a 30w panel to keep our total 550ah batteries topped up (that includes engine start and thruster batteries, all connected via VSRs) .
I am about to purchase said panel. I was going to remove the panels from the arch altogether to remove windage and wondered if this might also remove the (admittedly slow) rate of diminishing efficiency of the panels over the years?

Diesel - my vote is with the full tank brigade.
Water tanks - empty and then next year sterilize the system and thoroughly flush through.
Service engine - fresh oil is better sitting around over the winter (did I read less corrosive impurities?)
I will run antifreeze into the raw water side of the cooling system as we will be in Northern France - and as well as freezing prevention has anti corrosion properties.
Regards
Paul

 

[johnalison]

When I had a raw-water cooled volvo I used to run fresh water with inhibiting oil through, adding antifreeze for the last bit, following the maker's instructions.

 

[GHA]

I am pleased this has been raised as I have been pondering how to leave our 240w solar panels and batteries overwinter. They charge batteries via an MPPT controller but I did wonder if there may be an issue with the controller allowing a period of bulk charge each morning as the sun rises, overcharging already full batteries?

I've had a panel go bad and completely trash 2 newish US battery 2200's a little while back so am very wary of leaving anything at all connected now, especially as there seems to be little benefit -
http://www.pbase.com/mainecruising/self_discharge

I finally got a chance to perform an equalization and then conducted a 20 hour capacity test on this battery. It completed the test with 78.8% of the 20 hour rated capacity.

If you were paying attention early on in this article, this 6 year old battery had previously tested at 79.4% of rated Ah capacity. After sitting for nine months, through a full winter and then a hot summer in my shed, the battery lost only 0.6% of its previous tested Ah capacity. My suspicion is that if I had tested it in April I would have seen minimal to no loss and the summer heat is what really caused this minor loss of capacity.

A pair of T105's were left alone from last May to Sept in a hot boatyard and still had a high SOC at the end, unable to do an accurate capacity test to see how they fared but no obvious degradation.

 

[lw395]

I've had a panel go bad and completely trash 2 newish US battery 2200's a little while back so am very wary of leaving anything at all connected now, especially as there seems to be little benefit -
http://www.pbase.com/mainecruising/self_discharge



A pair of T105's were left alone from last May to Sept in a hot boatyard and still had a high SOC at the end, unable to do an accurate capacity test to see how they fared but no obvious degradation.

Some batteries have very low self discharge.
Others don't.
I've had batteries that lose noticeable charge after 6 weeks on a boat isolated by a good old 1-both-2 switch, despite working well in all other respects. I've known countless people have to buy a new motorbike battery after the winter, even with old bikes where there is no alarm or ECU drain.

We don't float charge our standby batteries just for something to do.

Personally I'd go for a solar float charger regulated at around 13.3V or whatever the battery maker says.

 

[[70521]]

I'm aware of the conventional wisdom.
I don't rate it highly.
I think somebody busted this bit of folklore a while back.
Might still be valid if you have a mild steel tank though.

Diesel has changed.
8 months in a vented container is a long time.

I'm told the balloon trick probably won't go well as the vapour from the diesel will attack the rubber.
If the tanks can stand the pressure, a vent valve which only lets air 'in' is commonly fitted to the vent of motorbike tanks.
One might want to remove it before trying to refill the tank or it will throw fuel back at you.

Have you any evidence to support your position?

 

[jdc]

In response to the question about filling tanks vs empty tanks over winter, I also come down on the side of empty. My reasons are two-fold:

Firstly, fuel is not that stable, and one should really use fresh fuel when possible. This to a large extent because Ultra-Low Sulphur Diesel is less stable than pure distillate due to the lack of the inhibiting properties of the sulphur and because we just make more diesel than hitherto by catalytic cracking, which leads to degraded stability. There are loads of articles on this, incl some from the military. In addition, since the OP is in Spain I assume he's using diesel with 5% FAME added as well - it's illegal in Spain to use anything but white diesel in the tank, and this will inevitably be road diesel. This is even less stable, and it's recommended to keep it for 6 months max.

Secondly condensation in fuel tanks seems not to be well documented at all: in fact I can find no quantitative articles describing it, but can find some challenging it. See for instance http://www.pbase.com/mainecruising/fuel_tankt_condensation

Hence my preference is for empty, and re-fill with new, dry, fuel in spring.

 

[RichardS]

If my diesel tanks are full at the end of the season, they stay full for the next 6 months. If they're empty at the end of the season they stay empty for the next 6 months.

I usually syphon out the water tanks. I don't drain them through the taps as there's no point in running the water pump for no good reason.

Richard

 

[Leonidas]

Some skippers also slacken slightly the tension on the standing rigging, Usual other jobs are also to remove, inspect and wash the sails with fresh water and either keep them in a local sail-makers loft or in their sail bags onboard after ensuring that they have properly dried, same for the Bimini and other canvas sprayhood; fresh water wash the warps and sheets, grease the winches and covered them, wash and dry the bilges and leave the cabin sole panels open to ventilate. I also met skippers who apply Vaseline over the stainless steel, but this might be getting a bit too much? Then there is also the outboard motor and the dinghy to take care of. and don't forget to get rid of all the perishable food before you lock up and go away. If the boat is on hard stand, some marinas recommend that the keel is resting on some substantial piece of wood so that the boat does not earth in case of a lightning strike.