Fitting battery charging advice please

[Refueler]

A shore power cable coming aboard has to be routed to avoid chafe, so same difference with any other cable.

Claims were also made that shore installation don't have "fuses", which is nonsense.

If people post nonsense on here they can expect to be picked up on it, it's a feature of internet forums.

Lets look at this .... how many times have you seen mooring lines ... power cables .... rigged such that chafe is inevitable ? I am sure we can all recall or have seen such ...

I agree that chafe should be avoided whether power cable or other ... but its not always the case ... the human factor of "that'll be alright" too often comes into play.

My power cable needs to be re-routed and proper 'Blue socket' fitted .. I have large enough surface area of cockpit to mount external ... but need wait till I get to UK to buy ... over here the availability of such is limited. I will also be fitting breakers / RCD ...

 

[PaulRainbow]

Lets look at this .... how many times have you seen mooring lines ... power cables .... rigged such that chafe is inevitable ? I am sure we can all recall or have seen such ...

I agree that chafe should be avoided whether power cable or other ... but its not always the case ... the human factor of "that'll be alright" too often comes into play.

My power cable needs to be re-routed and proper 'Blue socket' fitted .. I have large enough surface area of cockpit to mount external ... but need wait till I get to UK to buy ... over here the availability of such is limited. I will also be fitting breakers / RCD ...

I don't disagree about chafe, but that's not what i meant. Chafe applies to whatever lead you bring aboard, BoaterSam claimed you should not use an extension lead because of chafe, but the same considerations apply to any lead.

However, my main reason for saying that post was nonsense was the claims that shore power installations don't have fuses or that the circuit breakers are rated higher than the cables. Nonsense.

 

[Refueler]

I don't disagree about chafe, but that's not what i meant. Chafe applies to whatever lead you bring aboard, BoaterSam claimed you should not use an extension lead because of chafe, but the same considerations apply to any lead.

However, my main reason for saying that post was nonsense was the claims that shore power installations don't have fuses or that the circuit breakers are rated higher than the cables. Nonsense.

I'm not disagreeing with you ..... and I think everyone gets the point - even Boater Sam !!

 

[Boater Sam]

I don't disagree about chafe, but that's not what i meant. Chafe applies to whatever lead you bring aboard, BoaterSam claimed you should not use an extension lead because of chafe, but the same considerations apply to any lead.

However, my main reason for saying that post was nonsense was the claims that shore power installations don't have fuses or that the circuit breakers are rated higher than the cables. Nonsense.

A 16A shore breaker is not rated higher than the average 1.25mm2 13A extension cable? Your nonsense.
A domestic 13A extension lead fed in through a door will never get caught and trapped in the hinge or chaff on an unprotected metal edge? More of your nonsense.

 

[B27]

I think galvanic isolation is important.

When my boat was in a marina for a short while, I just used a lead with a twin socket and a double-insulated battery charger, and some double insulated tools.
And a double insulated fan heater.
I did test the RCCB on the pontoon though.

The paperwork which came with my boat contained a fair few receipts for anodes.

The most important safety thing is treating mains cables with care and respect.
Make the effort to be sure it's not chafing and the ends are kept dry.

And if you're in a berth for a while, get a cable of the right length, you don't want it coiled up, tripped over, excessively wrapped around things....

 

[shanemax]

How often are you going to be onboard, how often are you going to be away from the marina sailing and what amps do you require. Are you going to be running any high load items like fridges, de humidifiers (in the winter.) I have a total of
100 watt solar with two batteries total 160 amps and this powers every thing I use. Auto Helm, Small inverter, Lights,
I phone charging, Kindle charging, mobile charging and 12 volt vacuum. I use the boat a lot between May/Oct and have, as yet not been caught out being short of power. In fact I have one main use battery and one rarely used being trickle charged by a 10 watt panel so it is always sitting at maximum charge.

 

[PaulRainbow]

A 16A shore breaker is not rated higher than the average 1.25mm2 13A extension cable? Your nonsense.
A domestic 13A extension lead fed in through a door will never get caught and trapped in the hinge or chaff on an unprotected metal edge? More of your nonsense.

No-one mentioned a 13a lead, except you.

 

[PaulRainbow]

I think galvanic isolation is important.

When my boat was in a marina for a short while, I just used a lead with a twin socket and a double-insulated battery charger, and some double insulated tools.
And a double insulated fan heater.
I did test the RCCB on the pontoon though.

The paperwork which came with my boat contained a fair few receipts for anodes.

The most important safety thing is treating mains cables with care and respect.
Make the effort to be sure it's not chafing and the ends are kept dry.

And if you're in a berth for a while, get a cable of the right length, you don't want it coiled up, tripped over, excessively wrapped around things....

There is no need to fit an anode if using one of the camping cables, or any other power system that keeps the incoming shore power Earth isolated from the water.

Edit, meant to say Galvanic Isolator, not anode.

 

[VicS]

No-one mentioned a 13a lead, except you.

Boater Sam has chucked some red herrings into the ring but has failed to notice one important fact.
One at least of the campsite hookups I mentioned in #2 is only rated at 10amps . . . . . . . . . It may only have 1.0mm² cable. . . . . That's something to check.
.

 

[B27]

There is no need to fit an anode if using one of the camping cables, or any other power system that keeps the incoming shore power Earth isolated from the water.

I agree, but personally I'd be cautious about stuff with exposed 'earthed' bits.
I have felt the difference between shore and boat earth.
I have a mate who thinks he blew up some electronics using a shore-earthed soldering iron.
Trust Nothing!

 

[PaulRainbow]

I agree, but personally I'd be cautious about stuff with exposed 'earthed' bits.
I have felt the difference between shore and boat earth.
I have a mate who thinks he blew up some electronics using a shore-earthed soldering iron.
Trust Nothing!

I meant to say "galvanic isolator", not "anode". No point at all in fitting one if just using one of those camp site cables as there is no shore power Earth connection to the water.

 

[B27]

I meant to say "galvanic isolator", not "anode". No point at all in fitting one if just using one of those camp site cables as there is no shore power Earth connection to the water.

I assumed that's what you intended.

With the popular makes of built-in battery charger, are they mostly mains-earthed to the DC Zero volts?
It's all easy enough using a small charger with a plastic case and no mains earth.

In my view, you don't want things like a metal kettle earthed to the shore and your sink and taps earthed to the water.

 

[rogerthebodger]

There is no need to fit an anode if using one of the camping cables, or any other power system that keeps the incoming shore power Earth isolated from the water.

Edit, meant to say Galvanic Isolator, not anode.

An anode is important when yo have dissimulate metals electrically connected in sea water.

A galvanic Isolator is needed when yo have an mains protective earth leas commented to anodes and the electrically anode also connected to the incoming protective earth.

I have a metal boat with my anodes connected to the conductive hull and then anodes are also connected to the conductive hull. My GI is to prevent mu anode from protecting and dissimilar metals outside my boat from causing my anodes protecting any boat outside.

If you have a GRP boat most metal fittings in sea water will be electrically isolated metales from each other unless linked deliberated.

The one exception is a bronze prop on a stainless steel prop shaft would need a shaft anode.

All my underwater fittings are stainless steel so my anodes do last a long time as the is very little galvanic current flow coursing erosion.

Its all about the science of galvanic actions

 

[PaulRainbow]

I assumed that's what you intended.

With the popular makes of built-in battery charger, are they mostly mains-earthed to the DC Zero volts?
It's all easy enough using a small charger with a plastic case and no mains earth.

In my view, you don't want things like a metal kettle earthed to the shore and your sink and taps earthed to the water.

Correct Earthing consists of the shore power, as normal, and a connection to the water. Every Earth connection is on that same circuit. There is no need to connect AC Earth to DC negative.

 

[PaulRainbow]

An anode is important when yo have dissimulate metals electrically connected in sea water.

A galvanic Isolator is needed when yo have an mains protective earth leas commented to anodes and the electrically anode also connected to the incoming protective earth.

I have a metal boat with my anodes connected to the conductive hull and then anodes are also connected to the conductive hull. My GI is to prevent mu anode from protecting and dissimilar metals outside my boat from causing my anodes protecting any boat outside.

If you have a GRP boat most metal fittings in sea water will be electrically isolated metales from each other unless linked deliberated.

The one exception is a bronze prop on a stainless steel prop shaft would need a shaft anode.

All my underwater fittings are stainless steel so my anodes do last a long time as the is very little galvanic current flow coursing erosion.

Its all about the science of galvanic actions

Thanks for educating me Roger, what would i do without you ?

 

[rogerthebodger]

Thanks for educating me Roger, what would i do without you ?

Paul I am sure you know all of this so no need to thank me but we may have people on hear who much less knowledge than you or myself and that is what I am here those with less knowledge

Is that why you are here ?

Just note we all can make mistakes and as long as we correct then its all OK

 

[VicS]

An anode is important when yo have dissimulate metals electrically connected in sea water.

A galvanic Isolator is needed when yo have an mains protective earth leas commented to anodes and the electrically anode also connected to the incoming protective earth.

I have a metal boat with my anodes connected to the conductive hull and then anodes are also connected to the conductive hull. My GI is to prevent mu anode from protecting and dissimilar metals outside my boat from causing my anodes protecting any boat outside.

If you have a GRP boat most metal fittings in sea water will be electrically isolated metales from each other unless linked deliberated.

The one exception is a bronze prop on a stainless steel prop shaft would need a shaft anode.

All my underwater fittings are stainless steel so my anodes do last a long time as the is very little galvanic current flow coursing erosion.

Its all about the science of galvanic actions

Anodes and cathodic protection is a whole different topic.

P.R meant "galvanic isolator" in post #48 when he said "anode. An error he corrected half an hour later.

However, the fact that the campsite devices are unlikely to have their earths connected to the water, as is required for a "proper " shorepower installation, raises another issue.

As I understand it the "connection to the water" provides an alternative earth connection for the shorepower installation. When flexible cables and plug and socket connections are involved a discontinuity in one of the conductors due to corrosion in plug or socket, loose connections, or even a broken conductor becomes a possibility. If this occurs in one of the live conductors it will be quickly noticed, because equipment won't work, but probably not if it is the earth conductor ( Unless there are warning lights as I know you have.) The "connection to the water" provides an emergency back-up connection and maintains the safety aspect of the earth connection. It is probably , although not impossible, to make this connection to the water when using a temporary shorepower connection such as a campsite unit.

 

[B27]

Correct Earthing consists of the shore power, as normal, and a connection to the water. Every Earth connection is on that same circuit. There is no need to connect AC Earth to DC negative.

But DC zero volts is commonly (sic) connected to the water, via the engine.

I'd agree that 'correct' earthing would generally seem to be implying connect the boat's metal (and the water) to the shorepower earth, via a galvanic isolator, which will pass current if the difference exceeds a few volts. I'd only be happy with anything less if every AC load was double insulated and people were being careful.

Shore Power is not trivial. Best avoided as much as possible.

 

[PaulRainbow]

But DC zero volts is commonly (sic) connected to the water, via the engine.

I'd agree that 'correct' earthing would generally seem to be implying connect the boat's metal (and the water) to the shorepower earth, via a galvanic isolator, which will pass current if the difference exceeds a few volts. I'd only be happy with anything less if every AC load was double insulated and people were being careful.

Shore Power is not trivial. Best avoided as much as possible.

The engine is not always connect to the water and DC zero is not always connected to the engine block, so routinely using either is not reliable. Most modern engines have flexible couplings, for instance.

There is no need to have everything double insulated, you're just making things more complicated than they need to be.

It's really, really, really simple. All onboard Earth points are connected together, the shore power Earth and the connection to the water are both connected to this circuit. The connection to the water can be made in several ways, a connection to the hull of a metal boat, and Earthing plane or an anode. If the engine block is connected directly to the water via the shaft and prop, that could be used too, DC negative is irrelevant, electrical continuity to the water is all that matters.

FYI fitting shore power systems is part of my day job.

 

[Refueler]

I think there is one aspect that must be taken into account : Alastair Garrod makes a serious point about it in his book many times in fact ...

Current will find the fastest and least resistant path to ground ... that may be through the guy who just grabbed hold of faulty gear ... instead of the cabled ground fitted ...

Good book IMHO