Fitting battery charging advice please

[GoatsonaBoat]

Hi folks,

Long time reader. First post. Just taken delivery of a 24' Atlantic Marine 720. Previous owner kept her on a trailer and used portable small chargers, we are now keeping her in a marina and i want to fit a permanent battery charger so I don't have to faff around and can just plug in a know the batteries will be charged. I'm tech savvy and have done a bit of electrics in my time but im no expert hence im asking for advice. The boat has 2x AGM batteries.

I would like to use a Mastervolt 12v 2 bank 10a charger.

I don't want to use shore power for anything other than charging the batteries, what would you knowledgeable folks suggest? Simple fit and connect up via cable etc? Or fit a shore power plug on the boat, if it is just for this charger will i need an rcd etc etc.

Help would be much appreciated!

Thanks

 

[VicS]

A campsite hook up might be the answer if you don't want to install a proper fixed shorepower system.

Maypole Electric Hook Up Mobile Mains Power Unit 230V / 10A

5-Way Mains Unit with USB

Two examples from the same supplier but others to chose from . They have an rcd and a mcb and will be useful if you need to run corded power tools or domestic appliances

 

[Boater Sam]

Don't just run an extension cable in, its very dangerous.

 

[GoatsonaBoat]

Don't just run an extension cable in, its very dangerous.

So the previously suggested options with rcb etc, the camper type, have seen a marine one then are no good? Why so surely it’s the same thing in essence as fitting an rcb? Or am I being dumb haha

 

[Alex_Blackwood]

Don't just run an extension cable in, its very dangerous.

That is a sweeping statement! What is your shore power cable if not and extension? FWIW Shore power cables should be 2.5 mm CSA cable and no longer than 25mtrs.

 

[Stemar]

I used an extension cable for years with no problems. The supply box in a marina will have an RCD, so you won't get your hair curled if you do get it wet, at least in the UK, though setups in other countries may not be to the same standards. What you don't want is an ordinary 13amp socket and plug sitting in the rain.

I'm not an electrician, but I'd have no hesitation in using a camping lead like those VicS suggests. Just keep the sockets in the dry.

One other thought. We had a 24 footer for years. One of the best investments for her was a pair of 20w panels and a cheap dual battery controller. It meant the batteries were always fully charged when we came to the boat, even midwinter, and it would even keep up with our modest needs at anchor during the summer.

You could spend very little more than you'd spend on your charger and a lead, and have no leccy charges ever again.

 

[PaulRainbow]

Hi folks,

Long time reader. First post. Just taken delivery of a 24' Atlantic Marine 720. Previous owner kept her on a trailer and used portable small chargers, we are now keeping her in a marina and i want to fit a permanent battery charger so I don't have to faff around and can just plug in a know the batteries will be charged. I'm tech savvy and have done a bit of electrics in my time but im no expert hence im asking for advice. The boat has 2x AGM batteries.

I would like to use a Mastervolt 12v 2 bank 10a charger.

I don't want to use shore power for anything other than charging the batteries, what would you knowledgeable folks suggest? Simple fit and connect up via cable etc? Or fit a shore power plug on the boat, if it is just for this charger will i need an rcd etc etc.

Help would be much appreciated!

Thanks

A cable along the lines of those in post #2 would do the job and be safe.

I'd consider fitting a shore power socket though, it would be tidier and you wouldn't have cables poking out of lockers etc. Just fit the socket and connect it to an RCBO in a small enclosure, close to the battery charger, then connect the charger to the RCBO, or better yet, fit a double socket so you have the ability to plug something else in (power washer, hoover, kettle, phone charger etc), you never know. All parts available from the likes of Screwfix.

 

[Boater Sam]

That is a sweeping statement! What is your shore power cable if not and extension? FWIW Shore power cables should be 2.5 mm CSA cable and no longer than 25mtrs.

That is one reason why an ordinary extension lead is dangerous. Another is that it is not entering the boat via a proper chaff proof entry point. And there will be no fuse to protect the cable in the event of overload, 16A sockets on marinas have no fuse. The breaker is probably rated higher than the lead.

 

[VicS]

A cable along the lines of those in post #2 would do the job and be safe.

I'd consider fitting a shore power socket though, it would be tidier and you wouldn't have cables poking out of lockers etc. Just fit the socket and connect it to an RCBO in a small enclosure, close to the battery charger, then connect the charger to the RCBO, or better yet, fit a double socket so you have the ability to plug something else in (power washer, hoover, kettle, phone charger etc), you never know. All parts available from the likes of Screwfix.

but it should be a double pole RCBO rather than the more common single pole device ?
and being aware than even many those listed as DP are SP + N and do not actually switch both poles ?

For a simple fixed shorepower connection I'd be looking at a "garage consumer" unit with DP RCD and 2 MCBs
.

 

[PaulRainbow]

That is one reason why an ordinary extension lead is dangerous. Another is that it is not entering the boat via a proper chaff proof entry point. And there will be no fuse to protect the cable in the event of overload, 16A sockets on marinas have no fuse. The breaker is probably rated higher than the lead.

What absolute and utter rubbish.

 

[Boathook]

That is one reason why an ordinary extension lead is dangerous. Another is that it is not entering the boat via a proper chaff proof entry point. And there will be no fuse to protect the cable in the event of overload, 16A sockets on marinas have no fuse. The breaker is probably rated higher than the lead.

At my berth the power supply is protected by a double pole rcd and a 16 amp circuit breaker. On board I also have a double pole rcd plus a couple of rcb's to protect individual circuits.

 

[Boater Sam]

What absolute and utter rubbish.

Glad you think so, hopefully you will electrocute yourself. How rude a person you are.

So that is why the Boat Safety Scheme would fail a boat with an extension lead instantly instead of an installed shore power connection?

You may get away with it on the briny but it is not correct.

 

[Tranona]

Glad you think so, hopefully you will electrocute yourself. How rude a person you are.

He may be rude and to the point - but broadly correct in his response to your scaremongering!

 

[Boater Sam]

He may be rude and to the point - but broadly correct in his response to your scaremongering!

Not scaremongering, its the inland waterways regulations. Is that to the point enough for you?

 

[rogerthebodger]

If its just to keep you battery charged up so its ready for use have you considered a small solar panel connected to the battery via some type of solar controller.

I have that setup on my little motor boat and will have a similar setup on my dingy battery and trolling motor for short distance trips

 

[Boathook]

Not scaremongering, its the inland waterways regulations. Is that to the point enough for you?

Just because some quango wrote some rules, doesn't mean that they are any good.

I read some of the inland waterway regs and felt that most were a waste of time. I've also heard of some factory supplied seaboats, set up for sea going, had to have systems degraded to pass the waterways regs.

 

[Refueler]

If its just to keep you battery charged up so its ready for use have you considered a small solar panel connected to the battery via some type of solar controller.

I have that setup on my little motor boat and will have a similar setup on my dingy battery and trolling motor for short distance trips

My 5m mobo has a small solar panel which requires no controller to the 12v SLA ..... no need for shore power ...

My 8m Motor sailer has shore power through DP breaker .... but when no service - the two batts (90A/hr each) are trickle charged by 20W solar via a dual output controller ...

My 38ftr - guy fitted a simple lead ... loose plug in transom locker - other end single plain socket under companionway steps. No fuse / RCD at all - relying on shore power pedestal. NOT A GOOD IDEA .... and will be changed soon - to a proper 'blue' external socket then to a Double Pole protective system ...

 

[Tranona]

Glad you think so, hopefully you will electrocute yourself. How rude a person you are.

So that is why the Boat Safety Scheme would fail a boat with an extension lead instantly instead of an installed shore power connection?

You may get away with it on the briny but it is not correct.

That does not mean they are unsafe in the way the OP wants to use one. Thousands in use in exposed position bt caravanners and campers - don't seem to recall an epidemic of people being electrocuted.

 

[PaulRainbow]

Glad you think so, hopefully you will electrocute yourself. How rude a person you are.

Not sure why i would electrocute myself, my suggestion was a proper shore power inlet, with an onboard RCBO

So that is why the Boat Safety Scheme would fail a boat with an extension lead instantly instead of an installed shore power connection?

I didn't suggest an extension lead, neither has anyone else in this thread. Besides, it's rubbish that a boat would fail the BSS for having an extension lead onboard.

Another is that it is not entering the boat via a proper chaff proof entry point.

More nonsense. an extension lead would surely come aboard via the same route as ashore power lead ?

And there will be no fuse to protect the cable in the event of overload, 16A sockets on marinas have no fuse. The breaker is probably rated higher than the lead.

If someone just used an extension lead or they used a proper shore power installation they would plug the cable into the same receptacle on the pontoon, that's what provides protection to the cable, nothing onboard can do so.

16a sockets on the marina have no fuses, but there is an overrated the lead, huh ??? "Normal" UK shore power is 16a max (of course there are 32a, 64a etc available) and ashore power cable should be 2.5mm, which is typically rated at 30a, even 1.5 is 21a. I think you might find it's a legal requirement for shore power installations to be fitted with RCDs and MCBs or RCBOs.

 

[GoatsonaBoat]

thanks for the responses folks. Enjoyed reading all that. Lots of good ideas too. I spent hours overnight reading things as I couldn’t sleep much anyway and seems to be a heck of a lot of conflicting info into there.

Went to local chandlery today and bought the charger I posted. Currently I’ve hooked it up while I do some other bits and am here todsy but I think I’d like to get a proper shore power system in place. Having said that the solar panel idea doesn’t seem bad either!

I also bought a galvanic isolator and planned to install a shore power system myself. Just a simple in plug, galvanic isolator, charger I posted off to the batteries and maybe a separate plug for things on board. Planned to get an rcd and mcb. What I cannot fathom is earthing. Current the earth seems to go to neutral on one of the batts but no where else. What on earth do I do to earth / ground ? Thanks