Extended lay up problems

[nomadicstar]

Good morning forum, just wondering what others do when leaving ship unattended for long periods. Main issues are reg electrics. does one leave shore power supply connected even though No draw for possible 4/5 mts at a time. Or is it best to have batteries disconnected and maintained ?
Would really appreciate some advise please.

[ANTREVELL]

I have a solar panel and wind generator which keeps all my batteries topped up over the winter period.

Regards Tony Revell   Pegatha Cruiser 33

[Lyra]

In the single time that I left my boat unattended for 6 months I did not leave it connected.
Batteries were disconnected and a small solar panel (5W) was attached to them just to compensate for their self discharge. I put a diode in series for each battery so that any problem in one of them would not draw current from the rest.

[Neil]

If you have a shore power supply available you could consider using it to keep the batteries topped up and also run a dehumidifier. If doing this the dehumidifier should be run on the 230V socket, so that if the power supply trips the batteries are not run down. The electrics benefit from being kept very dry (especially free of condensation), as does everything else on the boat.

[Symphony]

Would not leave shorepower connected unattended for that length of time, particularly if you run a dehumidifier - which should not be necessary if the boat is well ventilated. As suggested already if your batteries are in good condition then they only need a small solar panel to deal with the self discharge. So disconnect the batteries from your system and use a solar panel.

[nomadicstar]

Thank you very much for your reply's , my main problem being our boat will be shut up completely except for 1 coach roof vent.

My main worry is that the the 4 batteries will be exposed to excessive heat inside the boat during the long summer months (moored East Med) and I am worried that connected to shore power, it would manifest a problem should a problem arise on board.

My only other question is if I disconnect the shore power will it do lasting damage to the batteries (other than they will self run down over a period)

Our ship has always been dry so No dehumidifier.

[Lyra]

My boat has been located in the east med for the last 6 years.
The summer temperature in the cabin is not great for the batteries but will not cause damage.
Put a "boom tent" - no need for something fancy, a dense shade net is good enough - this will lower the temperature in the cabin by ~5 degrees.
Do not leave the batteries for 6 months without any charger to maintain self discharge - self discharge (or any very slow rate discharge rate) is "lethal" to batteries and irreversible. As said - put a small solar panel - for a low power panel you do not need a charge controller.

[Neil]

Excessive heat is not something we suffer from in the North. We tend to get condensation when the sea temperature drops below about 5 degrees and ventilation alone is not sufficient to deal with it. Low air temperatures in a wet environment don't dry well. Freezing pipes can also be an issue so laying up would usually involve draining the system including the calorifier, or ensuring some form of safe heating is available.

[suibhne]

For the last three winters I have laid up on the hard without a mains cable attached.
My method is a 20w photocell connected to my two service batteries and a 10w photocell connected to my starting battery.
The photocells are active all year round
The power switch on the boat is turned off
The boat is a BAV 36(2003)  and based at Troon Scotland (not a lot of winter sunshine) 

[Neil]

I keep mine in the water, in the vein hope that I will get down to sail it once or twice over the winter. Maybe that is slightly mad, but I am a boat owner. Western isles in January?

[Kibo]

I leave my boat on the hard for 6 months in Grenada summers. No problems with heat on the batteries so far. I also use solar panels to maintain the charge. I did not have my bow thruster battery connected to the solar panels one year (my error) and it ran down with the result that it would not hold charge when I splashed her in November so it had to be replaced.

I can also recommend a guardianage or "boat watch" service. For a relatively small monthly fee a reputable company will inspect the exterior and interior of the boat once or twice per month (weekly in my case) and ensure batteries are maintaining charge, there is no mould or humidity issues etc etc.. they use hygroscopic crystals to dehumidify which are regularly changed as part of the routine inspections for example. I think its a very worthwhile expense.