How long away from the boat to disconnect shore power

Well, no consensus on a unique best practice, obviously.
Fwiw, before leaving the boat today (will be back in 12 days), I thought to try disconnecting AC, together with all domestic sevices bar bilge pumps, which bypass the disconnecting relay.
Fingers crossed for finding neither flat batteries nor a sunk boat... :)
 
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MapisM said:
Well, no consensus on a unique best practice, obviously.
Fwiw, before leaving the boat today (will be back in 12 days), I thought to try disconnecting AC, together with all domestic sevices bar bilge pumps, which bypass the disconnecting relay.
Fingers crossed for finding neither flat batteries nor a sunk boat... :)
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At least your charger wont catch fire or fry your batteries ( then the bilge pump wouldnt work either )
 
Have disconnected ever since our boat went bang a couple of years ago - a short in the marina - killed the main board.
Also I’ve had problems with swell and cables - but my fault entirely.
Now have solar - very pleased with the system and keeps on top of the DC system, pumps/fridges and so on while we are away, (not often now), and battery stays topped up.
I would unplug if possible based on my experiences and a couple or 4 solar panels and a decent charger are a good investment imho if you’re in the right locale...but far mor important for a sail boat than a mobo of course.
 
I see the merits of leaving the 12v system connected with the battery charger on for the bilge pump, but I suppose the risks of things like flat batteries due shore power tripping out, or cooked batteries, or electrical fire however unlikely seem more of a risk than sinking. Knowing the 12v battery capacity and voltage will be ok when we return because they were 100% isolated while away has always worked for us. We pay insurance so somebody else can have sleepless nights about risks of sinking in the marina, not us.
 
I leave mine plugged in 24/365. It’s too hard to reduce the boat to zero amps and I want the fridges and some deck lighting left on anyway.
I’ve never had a problem in nearly 20 yrs of doing this. I am truly galvanicly isolated from the dock, using transformers. Like bartw I use a yacht sentinel to tell me the charge status by sms.
 
I also leave the shore power connected and the battery charger on. I have only been doing this 10 year so its early days. I have no corrosion issues (two boats in 10 years , the first over 6 years - same home mooring the whole time).
Also I leave the fridge on as often there is a bottle of fiz or a beer or two in there. The fridge works directly off the 240V A/C power when it is connected .
The cost of shore power electricity to do this is very low and we always arrive to fully charged batteries and a nicely chilled fridge into which to put our freshly purchased milk etc.
Only risk is a battery fails but rarely more than a week passes without we at least visit the boat to check all is well.
 
petem said:
I leave my shore power and batter charger on all year. The logic being that if I sprung a leak then the bilge pump couldn't drain the battery. Of course the risk is that you fry the battery and start a fire.
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Play d'eau has her shore power 24/7, whether we are on board or not. Why? In case of a sea-water leak, a fresh water tank leak, and to ensure the fire and smoke warning kit remains active. All other equipment is isolated.
 
MartynG said:
I also leave the shore power connected and the battery charger on
...
Only risk is a battery fails
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Imho, it's somewhat greater the risk of a charger failure/short circuit/whatever - hence the thought of disconnecting everything.

I see the point of all those who are always plugged in, though.
Much more convenient, as long as electrical components work as they should...

Apropos, since it was mentioned, I'd be interested to hear more about that Yacht Sentinel thing.
 
My tuppence I suppose was shaped by bad luck and experiences on two boats over the years where batteries were destroyed, once by a faulty charger and a second time by a dead cell in a battery that caused another faulty smart charger to boil the other three in the bank. An internal short leading to battery failure on a light aircraft over sea 30 years ago when we lost all the avionics in IMC has also coloured my trust in batteries, especially just as we taxied onto the ramp the battery caught fire!!! :) The boats insured so I'm happy to do without bilge pump, more averse to cooked batteries and electrical fires, but that's probably just hyper caution. :)
 
Reading through this thread I’m surprised only one poster has mentioned solar. I’ve got a 50w panel through an mppt controller which can put over 3 amps into the batteries on a decent day. Boat’s on a fore and aft mooring with no mains, more than enough power to keep up with the bilge pump unless something catastrophic happens.
 
Glenlivet said:
Reading through this thread I’m surprised only one poster has mentioned solar.
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I'm not sure that there are reasons to be surprised - not in a MoBo forum, anyway.
At the end of the day, we are a bunch of shameless gas guzzlers who waste ridiculous amounts of the planet resources every time we move around...
...And that puts the dockside energy costs in perspective.
Btw, the inherent risk of having an electrical equipment running unattended is not that lower with solar energy, I suppose.
Far from being an expert, but I see no reason why MPPTs (or whatever bit of kit is required by such systems) couldn't fry as the old battery chargers can.

There are exceptions of course - Hurricane of this parish installed solar panels on his P67 (which definitely deserves to be included among gas guzzlers! :)) and he's happy with the results.
But he did that with the aim of using the genset less while he's away from his berth, afaik.
I don't think he would have bothered, as a replacement of dockside supply alone.
 
Glenlivet said:
Reading through this thread I’m surprised only one poster has mentioned solar. I’ve got a 50w panel through an mppt controller which can put over 3 amps into the batteries on a decent day. Boat’s on a fore and aft mooring with no mains, more than enough power to keep up with the bilge pump unless something catastrophic happens.
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You do get some surprises on this forum!
But yes, it’s strange that given the question asked, the merits of solar charging whilst away from the boat are not realised by more of this fraternity.
My personal experience has been twice I’ve been affected by poor dockside power. Once with a Big Bang and the other from a tripped shore box meaning the charge failed. Third time was my fault as I left my cables too short and caused one to fry the inlet.

But 12v trickling in keeps the battery charged, means that half the time I don’t even have to plug in when I’m day running from the marina to the anchorage and longer absences don’t require 2 x 230v cables to be kept plugged into the boat.

But for simple convenience I find the system I have runs my fridges, pumps, inverter and half the time now I don’t bother getting the cables out when we return to the marina.
But given the reasoning above, it’s a nice redundancy to have should the shore power trip whilst away from the boat - ‘specially if you’ve left the fridges on....
Still, different ships, different cap tallies
 
I would say it depends on many factors and each case is an individual case, insurance clauses would be my first port of call as even homes now have to have the gas and electricity turned off when they are empty according to several insurance policies, then they contradict themselves by saying the heating should be turned on during the winter months which required gas, electricity, and water leaving on; written clarification is something you need with regard to boats as well as other things such as homes.

Individual requirements also apply to a boaters needs and the equipment fitted, a fridge will cool down over time but a bilge pump or alarm system is a different issue and these need consideration as a flat battery may see your boat potentially stolen and you're not covered for its loss as you have the batteries disconnected and the alarm system doesn't work along with your tracker.

Battery condition is a major factor as all batteries discharge over time and this time period is crucial as a deeply discharged battery can ruin a battery bank and while constantly discharging batteries can be an issue it is the time period between charges which can have a detrimental effect on the battery or bank.

Solar and wind charging systems in the main are ineffective on boats, they require specific conditions to work and while they may provide a partial solution they are only delaying the discharging of a battery bank, similarly, invertors and other items connected directly to a battery draw power when not in use and in stand by mode and can discharge a battery bank below its safe point.

Intelligent charging is no guarantee either as most people fail to match a charging system to the battery system and unless it is matched correctly it can over or undercharge the battery bank and accelerate wear on the batteries and cause a failure.
 
Our domestic battery bank is EIGHTEEN years old and still working perfectly. Normal use domestic systems inc fridge on for 48hrs without charge still no problem. Our 12v domestic system is 4 x 175Ah 6v batteries, as two in series pairs in parallel.

We rarely have left the mains charger on when we leave the boat, instead we isolate the 12v system completely. The batteries have been fine after each winter having been off the charger for 5 months at a time. By contrast a pal with exactly the same boat, battery and charging system who leaves the smart charger on 24x7 all year round is on their 3rd set of domestic batteries and each spring has had to replace varying amounts of water in their domestic batteries because the so called 'smart charger' was very slowly boiling them off. There is probably no right or wrong, each setup is unique to each vessel, so whatever works for folks is probably best.
 
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