Solar Panel What Size for Sailboat Nauticat

graham460

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Hi Tranona Pmagowan..

Thanks for the reply I did know the 1st Section about ,
Bank 1 to Start Engine - then Switch to Bank 2 for Domestic.
and if Battery is Low USE bank 1 and Bank 2 To start the engine.. -
Not forgetting to Switch bank to Bank 2 to use the Domestic..

However I did not know you have to Use - Select switch to Bank 1 & 2 to Charge BOTH when running the Engine.

-------

I see no fuses on your battery terminals but I see quite a few cables connecting to one terminal. There are a number of approaches including manual 1/2/B switches and automatic VSR battery combiners.

I did not know you need fuses On Engine cables etc.

However I have 4 Dead batteries at the moment Need to Buy New ones

IT IS A TOSS UP BETWEEN EXIDE EP1200 THEY ARE ON THE BoaT NOW
OR
EXIDE 165AM HRS. BAT412151084 165ah 12 485 x 172 x 240 47 600 220

But a friend said he had heard of One of the Connecting Lugs snapping. Then it wuld be a pain sending them back to Supplier.
I'd like to use Victron Display and Products plus Global link 520 so I can see my battery at home in uk (Not that you can do much when boat is in Sardinia)
 

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Tranona

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Really difficult to get a proper feel for what powers what because there are so many cables on the battery terminals that could go anywhere. Don't think the green cable is anything to do with the bow thruster as from your photo its battery is charged by that mains charger. If it was being charged from the domestics (which would be unusual) it would be through s DC-DC charger and only small cables. However there are no signs of any other cables apart from those from the charger and out to the thruster. It could well be that the windlass is off one of the banks with heavy cables running from that bank forward through a fuse and a breaker.

As to batteries. Either replacements would be satisfactory, but the lug and bolt type are arguably better as they give more secure contact than the older type tapered lugs. Not a lot of point changing the type of terminal unless you are rewiring to use bus bars for distribution rather than all cables going to the terminals.
 

pmagowan

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You need to take it back to basics IMO. For a start we have given info on a typical (if old/obsolete) way of wiring. As pointed out there is no knowing how your boat is wired without a schematic. Your batteries have failed so there are problems somewhere and your system is obviously too complicated for you to understand easily/intuitively.
All wires that have potential to be fed more amps than they can handle need a fuse. If, for example, (as is not uncommon) there was a failure of the connection at the starter or alternator then that big red cable could fall onto the engine block and then you have a dead short and will make molten copper very fast along with the resulting fire.
There are fuses designed to fit on battery terminals which prevent this. I personally like to have minimal cables on the battery and use a heavy duty bus bar if lots of stuff needs connected. I would change your system to a switch cluster or just individual switches with a VsR for parallel charging
 

graham460

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Hello Tarona Oops I forgot your Question.

BOW THRUSTER Powered By the Domestic Batteries THAT IS the GREEN cable runs from Domestic Batteries through the boat to the BOW where is connects to a Battery and Battery Charger. The Green Cable is Only used to Charge the Battery in the Bow.
It was installed 2017 In Torreveja as the old one Corroded off.. The Mechanic that installed the New one Did not provide enough Power he installed 2 x 15mm Cable It blew the 500amp fuse a few times - So in PALMA a Company installed a Battery and Battery charger in the BOW

WINDLASS I have only ever used the Anchor Once.
YES it draws a lot of Energy I kept the Engine Running The Battery charger 9Sterling Power then works overtime)
Hello Tarona What is a SHUNT is that a splitter? Your text the shunt is fitted between the house negative terminal and the cable as it measures all the loads going out to provide the data for your monitor. The Solar company suggested a trickle charge from the Domestic to the Starter batters maybe around 1 or 2 amps Salesman says it may take approx 2-3 days to charge
CUSTOM 240W KIT - 2 REGS REGULATORS

2.00 100W Flexible PERC Range - SSP100MF 838mm x720mm FROM UK BUT MAY PURCHASE IN ITALY



2.00 70W Flexible ETFE Range 530mm x 735mm - A BUT MAY PURCHASE IN ITALY IF I CAN FIND THE CORRECT SIZE



2.00 SCC075015060R – Smart Solar MPPT 75V/15A - (12/24V) may change to

VICTRON BLUESOLAR MPPT 150V/45A - (12/24/48V​

2.00 Black Solar Cable 6mm Single-Core (2 x 12m ) with MC4

PROBABLY source this Locally



  • ASS030543020- Victron Energy GlobalLink 520 With Aerial extension 2metre
1.00 BAM030712000R- BMV-712 Smart Battery Monitor-Bluetooth



1.00 PMP121800000- Multiplus 12V/800VA 35-16A - 230V



1.00 16mm sq RED Battery Cable - 1000mm - 10mm LUGS



1.00 16mm sq BLACK Battery Cable - 1000mm - 10mm LUGS



2.00 1M - 4mmÇ Battery to Controller Cables & Fuse Kit - 10,20A



1.00 BATTERY MASTERS 58.290 58.29





Total
 

Tranona

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No. A shunt measures the current flow in and out of the battery bank and the net flow (loads minus charge) is displayed on your battery monitor. A splitter as its name implies splits the charge from the source (usually the alternator) between the 2 (or maybe 3) banks. a trickle charger from the house to the starter is common - I have one. That is because I don't have a mains charger to the start, only to the domestic. However because I have a dedicated high power start battery which is charged within minutes from start up by the alternator it is always near fully charged and has low self discharge. When the boat is not used for longer periods I use the mains charger periodically for the domestic and when that is being charged up to 1A goes to the start battery. This would not really work for you because you do not have automatic split charger and you can use both your banks for all loads so you could run your start batteries down below the point where a trickle charger is useful.

You do seem to have a charge splitter as it is part of the Sterling Power A2B charges controller which provides a stepped charge to the domestic and a float charge to the start bank. So your 1,2,B only selects which bank is used for loads.

Your photos in post#19 suggests that your bow battery is charged only by a mains charger as there is no sign of heavy duty cables to charge it from the engine, only the heavy cables to the thruster motor and lighter cables from the battery charger. it is not totally clear because the battery is in a different compartment from the thruster and charger
 

Sandy

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What is a SHUNT is that a splitter?
May I respectfully suggest that you purchase a few books on basic DC/boat electrics and take time to read up on the topic.

This will allow you to better understand what you are trying to achieve and, more importantly, give you the skills to fault find when something fails.

When a post asks what is a shunt alarm bells ring out in my mind that the poster has no understanding of the topic and given the length of time the thread has been running has done little to read up on the subject.

Sorry if this sounds harsh, but I have been on so many boats where things are botched and when things go wrong have taken some considerable time to work out what and how things went wrong.
 
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graham460

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Hello Fellow Sailors. Thanks for the advice..

At the moment I am still dealing with Sunshine Solar in Norwich We have sort of Come up with a system..
4 Solar panels 2 x 100 BOW AND AFT 2 x 70w = 340 Watts

Then the 6mm cables will go down through the roof - under the floor.. However I did see in a youtube quick Video someone the guy (in his Camper van) put in an On/off switch or breaker switch

So I was jsut wondering What Amperage switches do i need - as I am a little short of Backing board space so prefer small physical size.. But still need the correge Amperage

The 2 Victron Charge Controllers I have put on order are the

JUST WONDERING WAHT SIZE

SCC110030210 - SmartSolar MPPT 100V/30A - (12/24V) Plus Victron Bmv 712 and Cyrix Battery to Battery Link and a Cerbo / GX display

SO I WOULD LIKE TO INSTALL 2 on/off switches before the 2 MPPT's wondering what amperage to look for in the shops.. rgds Graham
 

jac

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You need to be clear on what is the smallest wire in your circuit and size for that. Assuming it's the 6mm cables will be sized for a nominal load of up to about 45 Amps ( but may depend on length and cable so check) If fitting a breaker it should therefore be a max of 40A ( but lower would be safer) but needs to be sufficient to carry the load. You don't say how the panels will be wired or voltage of the panels but assuming 20v panels in parallel, bow and stern then the 2x100W will be putting out a max of 10 Amps and the 2 x 70W will put out 7Amps. I would probably look for a pair of 20Amp breakers or possibly even 25 if there was ever the prospect of adding to those.

Never seen the need for an on/off switch before the controller - it just adds something to go wrong and the circumstances when you might want to turn it off are fairly limited. If you wanted to just cut the charging you could simply cover the panels which has the added benefit of protecting them from dirt / UV damage and may be useful if the boat is not in use for a period
 

graham460

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Hello Jac.
As I am not an Electrician, so I am a Belt & Braces kind of guy. So I prefer tp be Overkill so as Not to casue any damage to the System.. Health & Safety Etc..
I spke to the Company who are selling me the Victron 30amp Charge controllers.. They say " YOU SHOULD BE EQUAL TO YOUR CHARGE CONTROLLERS"
THE SMALLEST WIRE WILL PROBABLY be 6mm
The Largest will be the Cable " I have been told 60mm Sq" That is about 15mm dia (Large) that is from the Domestic battery bank to the Starter Battery bank 2.3metres away VIA a CYRIX system. THAT IS WHAT I HAVE BEEN TOLD.

PANELS TO PANELS WILL BE IN THE AFT SECTION - Joined together with 2 Cables coming around to the front area through a Entry protection cover. CABLE LENGTH 6mm x 12metres to charge controller or Switch - The Bow area same setup Flexible panels linked together and then 2 cables going through Plywood - then into an Entry Cover

2.00 x Dual Cable Entry Cover Low Profile (White)

Then Down to the Switches I hope to obtain.. ----- Then Down to MPPT 30 amp x 2 other equipment to come off this is BMV712 - a CERBO and a GX Display - Also a CYRIX connection from Domestic to Starter battery - and a Battery Masters from Domestic to Generator Battery.. There is a Bow thruster - this has it's own Battery Charger and i believe this is fed by the Large Green Cable which is only used for charging the DC battery charger. in the bow
 

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jac

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Hello Jac.
As I am not an Electrician, so I am a Belt & Braces kind of guy. So I prefer tp be Overkill so as Not to casue any damage to the System.. Health & Safety Etc..
I spke to the Company who are selling me the Victron 30amp Charge controllers.. They say " YOU SHOULD BE EQUAL TO YOUR CHARGE CONTROLLERS"
THE SMALLEST WIRE WILL PROBABLY be 6mm
The Largest will be the Cable " I have been told 60mm Sq" That is about 15mm dia (Large) that is from the Domestic battery bank to the Starter Battery bank 2.3metres away VIA a CYRIX system. THAT IS WHAT I HAVE BEEN TOLD.

PANELS TO PANELS WILL BE IN THE AFT SECTION - Joined together with 2 Cables coming around to the front area through a Entry protection cover. CABLE LENGTH 6mm x 12metres to charge controller or Switch - The Bow area same setup Flexible panels linked together and then 2 cables going through Plywood - then into an Entry Cover

2.00 x Dual Cable Entry Cover Low Profile (White)

Then Down to the Switches I hope to obtain.. ----- Then Down to MPPT 30 amp x 2 other equipment to come off this is BMV712 - a CERBO and a GX Display - Also a CYRIX connection from Domestic to Starter battery - and a Battery Masters from Domestic to Generator Battery.. There is a Bow thruster - this has it's own Battery Charger and i believe this is fed by the Large Green Cable which is only used for charging the DC battery charger. in the bow
I'm confused.

Are you not just talking about the breaker you want between panels and MPPT? Not sure why the other stuff is relevant??

You seem to be misunderstanding the role of a breaker. it is to switch things on and off of course but it is a device to protect the cable, not the devices attached to it which should have their own fuses. If you're after safety then you leave more capacity between the breakers capacity and the cables capacity.

It needs to be rated below the maximum safe load of the cable but above the maximum load you're going to put through it. 200W of Solar will put out 10A nominal - well within the 45A capacity of the cable. You could put a 40A breaker in there but it doesn't leave much headroom.

Whilst your MPPT might be rated to carry up to 30A they can't ever reach that input as your panels can't put out more than 10A ( Assuming 20v output and in parallel) in extreme cases, they may reach more than that ( and voltage may be lower, we don't know) but in theory any breaker between 10A and 40A would work. it's just not advisable to run things at their limits as that can damage the system. If the breakers are sized roughly halfway between the maximum load expected and maximum rating for the cable then you have plenty of breathing room to avoid damaging the system.
 

graham460

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Hello Jac..

Not 100% understand some of the quotes.. DESCRIPTION of system. Planned But not arrived in Sardinia Yet.
I will have 4 panels Bow 2x 100watts AFT area 2 x 70w att giving a total of Possible 340watts

Each set of 2 Panels will go down to its own Victron Controller 2 x SCC110030210 - SmartSolar MPPT 100V/30A - (12/24V)

I think this is Overkill as the Electrician (Now No longer interested) said 40 Amps total So Now I have 60 Amps 30 Amps in Each..

CABLE
The Cable will be 6mm Tinned - But I'm not too sure what the cable capacity is. The Length to MPPT is about 12m Max

QUERY
( Your Quote- If you're after safety then you leave more capacity between the breakers capacity and the cables capacity.) Not fully understand this quote - Forgive me for not being electrically minded..

The Shop where i am ordering the Victron equipment from Said - "People don't normally need a breaker, but you could put On/Off switch. Or indeed; A breaker It NEEDs to be rated at least the Same Size of the MPPT (30A) x 2 But a breaker you could Also use as an OFF switch, if you wanted to work on the system.

Your Quote. "halfway between the maximum load expected and maximum rating for the cable" I suppose the maximum load would be 340 Watts (NOT TOO SURE HOW TO TURN WATTS THAT INTO VOLTS)
Question NOT TOO SURE WHAT IS THE MAXIMUM RATING FOR THIS CABLE 6mm

BOW AREA
i think on the bow area 200w is about 17 amps

AFT AREA 2 x 70 Panels maybe around 12 amps so 2 x SmartSolar MPPT 100V/30A should be more than enough for each system.. Probably paid over the top but never mind It wa smy decision to Have Enough in the MPPTs

BUT WHAT I don't want to happen is put in a Breaker of such a size that it would trip easily especially as the boat is in Sardinia and I would b ein UK


I will be attaching a Victron Cyrix between the domestic (solar) to Starter bank.

QUESTION
DOES the system need to be earthed?
IF so Where would you put an Earth - could it be on the Engine

I am not able to Find any through Bolts to Anodes.. What about a Hull Valve? BUT WOULD NOT WANT THAT TO ACT AS AN ANODE AND CORRODED I ALREADY HAD THAT IN 2017 BOW THRUSTER FELL OFF IN TORREVEJA.
THANKS GRAHAM

boat is in Alghero too much sun to work
 
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