is OK to leave shore power connected ?

[arch007]

Wonder which is better ?


1. Leave shore power connected when you leave the boat ?


Pros


change battery for bilge pump


cons


chance of electrical short ?


Any other pros and cons ?


What do people do ?


Thanks

[Reefmagnet]

Many do. Pro's are power in tap. Con's are potential for electrolysis if the wiring is a bit iffy, and don't forget that the more you depend on having power connected, the more likely it will be that either the breaker will trip in your absence or that some nong disconnects it.

[billknny]

If your wiring is done right of course you can leave it plugged in. If your wiring is wrong, then: no telling.

Note to all: the electrons don’t know if you are there or not. So why would it matter if you unplug when you leave?

[CptCrunchie]

It depends on a few things. How long will you be away from the boat? What all do you leave running? Do you have solar to keep your batteries topped?

If you have solar, you likely would never need to plug in. But if you didn't have solar, with the electron soup of stray current in most marinas, I'd only plug it in to top up the batteries. Even the best galvanic isolators can fail.

[Calif.Ted]

Shorepower on, all 12 volt breakers except refrigerator off, water heater 120 volt breaker off, battery charger and outlets 120 V. breakers on, VHF handheld chargers and dehumidifier plugged into 120 V outlets.
Cold beer, dry cabin, charged batteries on return, never away more than a week.

[valhalla360]

Which is more likely to fail:
- Thru hull/shaft seal, etc...
- Electrical system

Either could but I've seen a few boats on the bottom of a slip due to a leak. I've only heard of electrical fires...so with electrical system with no noticeable issues, we typically stay plugged in.

[ohgary]

If you want to keep it plugged in but concerned about over charging then put a timer on it. On for a few hours a day off for the rest. That way your batteries are kept up, You limit the ovecharge, power issues or electrolysis..

[Lake-Effect]

Number one - have confidence in your boat's electrical system. Not blind confidence, but informed confidence: by understanding, working on and testing your own electrical system, or by hiring a good pro who has done that for you. And also confirming that your marina's shorepower is correct.

From there... it's your call, depending on your needs and wants (charging, fridge, etc)

[Stu Jackson]

I don't think those are the real issues.


It appears to me that the condition of your batteries should be the main contributing factor.


How long do you leave your boat without the batteries being charged at all? Self-drain is different for different battery chemistries. And, as mentioned solar can answer a lot of those questions. When I left my boat a few years ago for a month, I put a small 11W solar panel and controller on and things were just fine.


During the new-to-me winters here, I leave a heater going to avoid "rain" inside the boat. DC is all off, but AC is on.


When I lived in SF, I rarely left the boat even plugged in unless the batteries were PSOC when I returned to the slip, so I'd leave the charger going overnight, return the next day, unplug and was good for a week or two.



Your boat, your choice.

[surazo]

any of you had used an intelligent charger ? .I maintain shore power connected trough a smart charger .It detect the batt charge and disconnect this bank .It work fine for me .
Normally I include a thermical differential switch to prevent any shore power problem
any comments .thanks

[wsmurdoch]

Years ago we spent two weeks in North Carolina's Dowry Creek Marina having work done on our engine. Another cruiser had left his boat there with the fridge full and the power on. While he was gone, a breaker tripped, the fridge warmed, the food rotted, and the mold and flies moved in. When he returned, he was not the sort to take responsibility himself. It was both a social and a physical mess.

There are lots of things that can go wrong while you are gone. Prepare for them.

Bill

[CptCrunchie]

Originally Posted by ohgary

If you want to keep it plugged in but concerned about over charging then put a timer on it. On for a few hours a day off for the rest. That way your batteries are kept up, You limit the ovecharge, power issues or electrolysis..

Not so. 'Electrolysis' ..which is actually galvanic corrosion ....comes from being plugged into shore power, not whether you turn everything unneeded off. The green 'ground' wire connects every boat in the marina together. So, if you have one boat leaking a lot of energy, it could easily use your boat as a sacrificial anode. A galvanic isolator on your green ground wire right after it enters your boat will help, but it can still fail. Want an example?

In 2006, I completely rebuilt a 1968 Chris Craft Cavalier, tricking it out for tech diving.

Photo.jpg Views: 286 Size: 365.8 KB ID: 188231" style="margin: 2px" />



The correct wiring, breakers, I did everything right. That black box on the right with the blue label is a galvanic isolator.



This is what the props and rudders looked like.



Over the first 3 years, we used it a lot!



Then health issues. For 3 years it sat in its berth, with only the battery charger on. It had 14 zincs on: 4 on the SS trim tabs, 4 on the prop shafts, 4 on the rudders, a very large one on the transom, and a guppy hanging over the side connected directly to the STB engine.

After 3 years, I was finally able to pull the boat and give it some much needed TLC. This is what I found.



Even though there was still zincs on the shafts, I put a caliper on the shafts and they had each lost ⅛". The props were paper thin. Even the zincs on SS trim tabs were gone, and it had eaten the SS at the mounts. Except for two on the shafts, there was nothing left of the zincs ....except for the big one on the stern; the wire in the inside had rotted off, so it was still in like new condition.

I believe it was because I was berthed near 2 large commercial fishing boats that ran generators regularly, even while they were plugged into shore power.

So, ...your choice, keep it plugged in, or rig it up with solar panels so you can stay away from shore power.

[newhaul]

Originally Posted by CptCrunchie

Not so. 'Electrolysis' ..which is actually galvanic corrosion ....comes from being plugged into shore power, not whether you turn everything unneeded off. The green 'ground' wire connects every boat in the marina together. So, if you have one boat leaking a lot of energy, it could easily use your boat as a sacrificial anode. A galvanic isolator on your green ground wire right after it enters your boat will help, but it can still fail. Want an example?

In 2006, I completely rebuilt a 1968 Chris Craft Cavalier, tricking it out for tech diving.

Attachment 188231

Attachment 188232

The correct wiring, breakers, I did everything right. That black box on the right with the blue label is a galvanic isolator.

Attachment 188226

This is what the props and rudders looked like.

Attachment 188230

Over the first 3 years, we used it a lot!

Attachment 188233

Then health issues. For 3 years it sat in its berth, with only the battery charger on. It had 14 zincs on: 4 on the SS trim tabs, 2 on each prop shaft, 4 on each rudder, a very large one on the transom, and a guppy hanging over the side connected directly to the STB engine.

After 3 years, I was finally able to pull the boat and give it some much needed TLC. This is what I found.

Attachment 188225

Even though there was still zincs on the shafts, I put a caliper on the shafts and they had each lost ⅛". The props were paper thin. Otherwise, there was nothing left of the zincs ....except for the big one on the stern; the wire in the inside had rotted off, so it was still in like new condition.

I believe it was because I was berthed near 2 large commercial fishing boats that ran generators regularly, even while they were plugged into shore power.

So, ...your choice, keep it plugged in, or rig it up with solar panels so you can stay away from shore power.

6 years on the same zincs sounds to me more of a maintenance issue .
On dads boat we dive and inspect them monthly and replace when half gone ( about every 9 months )
on my boat since last for several years . Not plugged into shorepower unless needed for tools.

Lots of solar keeps batteries charged.

[CptCrunchie]

Originally Posted by newhaul

6 years on the same zincs sounds to me more of a maintenance issue .
On dads boat we dive and inspect them monthly and replace when half gone ( about every 9 months )
on my boat since last for several years . Not plugged into shorepower unless needed for tools.

Lots of solar keeps batteries charged.

It wasn't 6 years. We pulled it every year for the first 3, replaced the zincs the third year and they were about ½ gone. When we splashed, the marina put us beside the steel boats.

Originally Posted by newhaul

Not plugged into shorepower unless needed for tools.

My point exactly.

[Capt Phil]

We lived aboard a DeFever 54 for many years in a San Diego Marina and left our shore power on for weeks at a time. Pulled the boat regularly and dove to clean the bottom once every couple of months. The sacrificial zincs were only changed out about once a year with very little erosion on them. Mind you, I checked the electrical system thoroughly before we bought her in WA state and cruised her for about 6 months in the PNW then cruised down to San Diego for about a week.
We also spent about 1 1/2 years in Mexico cruising around the Sea of Cortez but based ourselves in La Paz.
As long as you keep a fairly close eye on your vessel, leaving shore power on should not be a problem but check your vessel regularly which you should do anyway. Who would go away and leave a major investment sitting there without checking her?
Phil