Yacht electrical system design

PaulRainbow

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A lot to process here lol from my understanding having the dc-dc charger all connected via the lynx distributor will allow the engine batter to be charged first before it redirects the charge to the house bank when using the engine/alternator?
Fair point about the engine battery isolator. From my thoughts the isolator that is connected to the house bank isolates the house bank from the lynx distributor. Maybe I labelled the diagram incorrectly confusing the situation sorry.
The Lynx and DC-DC charger will set you back about £400, a VSR will cost about £40 and do a better job, in this instance.

I see that the house isolator isolates the batteries from the Lynx, but everything is routed through the Lynx, so, for instance, your solar won't work if the isolator is off, neither will the mains charger.
 
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IanCC

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... but you wouldn't fit two, you just fit one with two outputs (actually three, as a rule).

My understanding is/was that a charger, unless very fancy, only had one sensor. Thus if sensor taken from a full starter battery it won't put much in the domestic batteries. Similarly if sense taken from run down domestic batteries, yet starter battery is full, then starter battery will get goosed by full charge being applied.

Have i understood wrong? 😊 Thanks for your time.
 

Carbalu

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The Lynx and DC-DC charger will set you back about £400, a VSR will cost about £40 and do a better job, in this instance.

I see that the hose isolator isolates the batteries from the Lynx, but everything is routed through the Lynx, so, for instance, your solar won't work if the isolator is off, neither will the mains charger.
you make a valid point about the cost however the cost isnt really what i was concerned with it was using the best equipment for the simplest system setup, i quite like how the feeds all come together into the lynx with ability to fuse internally as well without the need for loads of separate fuse blocks etc if you know what i mean?
In regards to the isolator switch, through looking at various victron diagrams alot of them have them there, my thoughts on that were that if i have a failure of the house bank they could be isolated from the system, leaving the solar connected via the lynx distributor to power items during the day if needed. The complete system would be isolated from any power sources via the house bank switch, solar isolators and the engine isolator switch (which i need to add) where would you insert the isolator switch in this setup? thank you
 
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rogerthebodger

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When you are designing panels and wiring allow extra for further expansion as there will be new equipment that you or subsequent owner may wish to fit some time later.
 

PaulRainbow

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you make a valid point about the cost however the cost isnt really what i was concerned with it was using the best equipment for the simplest system setup, i quite like how the feeds all come together into the lynx with ability to fuse internally as well without the need for loads of separate fuse blocks etc if you know what i mean?
Paying £200 for what is, in your case, a pair of busbars and some fuse holders doesn't seem simple to me.

If you want to keep fuses together, how about : Victron Mega fuse holder 6 way, rated up to 70V, 250A
In regards to the isolator switch, through looking at various victron diagrams alot of them have them there, my thoughts on that were that if i have a failure of the house bank they could be isolated from the system, leaving the solar connected via the lynx distributor to power items during the day if needed. The complete system would be isolated from any power sources via the house bank switch, solar isolators and the engine isolator switch (which i need to add) where would you insert the isolator switch in this setup? thank you
A lot of Victron schematics are domestic off-grid, or RV stuff. It would be odd to wire a boat up how you describe, where the charging systems don't work if the isolator is off.

If you fit the emergency parallel switch i suggested, in the event of a domestic bank failure all systems can run from the engine battery, with aid from any charging systems that are in play.

If the inverter has a problem, how do you isolate it without losing all other domestic systems and charging sources ?

With regards to the inverter and your proposed loads, unless you have reasonably substantial charging capabilities and a decent battery bank, using a mains kettle and hair dryer aren't likely to be viable. For instance, a standard mains kettle is 3kw, which will draw 300a from your batteries and a typical hair dryer will draw 150a - 200a. How big is your battery bank ?
 

dunedin

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My apologies, perils of being a newbie here and not explaining everything fully, I wanted the inverter charger in there as we will be doing quite a bit of extended cruising and wanting the facility for a. The mrs to use hair dryer, being able to charge laptop, use of a few small electrical items when at anchor like TV or kettle etc, not massive amounts but wanting to have the ability to use 240v if we need it
Charging laptops etc is fine.
But there is a reason that most people use a gas cooker for boiling water (when away from marina shore power) - as a kettle uses a lot of power, as do most hair dryers.
Fine on a big boat with extensive LifePO4 battery banks and major solar panels, but rarely on smallish boats.
 

samfieldhouse

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On the laptop front; it’s probably more efficient to go straight from 12v. Most laptops charge at 12-16v. Seems a bit of a waste to invert up from 12v to 240v then invert down again to the laptop charging voltage.

With the advent of USB C, there are many hi wattage charging options available straight from 12v.
 

PaulRainbow

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On the laptop front; it’s probably more efficient to go straight from 12v. Most laptops charge at 12-16v. Seems a bit of a waste to invert up from 12v to 240v then invert down again to the laptop charging voltage.

With the advent of USB C, there are many hi wattage charging options available straight from 12v.
A lot of todays laptops are 19v-20v, but your argument still stands. Most have 12v car charger options, a lot more efficient than using an inverter just to charge the laptop (as you say).
 
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Carbalu

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Paying £200 for what is, in your case, a pair of busbars and some fuse holders doesn't seem simple to me.

If you want to keep fuses together, how about : Victron Mega fuse holder 6 way, rated up to 70V, 250A

A lot of Victron schematics are domestic off-grid, or RV stuff. It would be odd to wire a boat up how you describe, where the charging systems don't work if the isolator is off.

If you fit the emergency parallel switch i suggested, in the event of a domestic bank failure all systems can run from the engine battery, with aid from any charging systems that are in play.

If the inverter has a problem, how do you isolate it without losing all other domestic systems and charging sources ?

With regards to the inverter and your proposed loads, unless you have reasonably substantial charging capabilities and a decent battery bank, using a mains kettle and hair dryer aren't likely to be viable. For instance, a standard mains kettle is 3kw, which will draw 300a from your batteries and a typical hair dryer will draw 150a - 200a. How big is your battery bank ?
Think I may have to re think the whole thing then, I was thinking around 300ah lithium and around 400w solar. It’s kind of hard to find decent resource online to plan out a full electrical system
 

Tranona

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Think I may have to re think the whole thing then, I was thinking around 300ah lithium and around 400w solar. It’s kind of hard to find decent resource online to plan out a full electrical system
That is perhaps because there are so many different (and often competing) ways of doing it. The starting point is understanding how you are expecting to use the boat and system - simple things like consumption over a typical day and whether and for how long you would like to be independent of shorepower. That provides the basis for determining your onboard charging and energy storage. It is mostly an iterative process but certain decisions like wanting 240v from 12v is a step change that has a major impact on storage and charging.

While there is a basic framework to follow, each boat tends to be individual in areas like how much space is available for batteries, and where; how much solar can be installed; how much reliance can be placed on the engine for charging. Obviously the size and layout of the boat has a big impact on what is feasible, and a typical 30' sailing yacht is small and often constrains what one can achieve. Hence my (and others) comment about having an inverter. Moving to lithium to support 240v means a different charging system and a big increase in charging capacity to get the best out of it.

I have done 2 complete rewires on old boats. The first one I bought a "kit" from Merlin who designed the system and provided all the hardware up to the DC panel and I had a panel custom made. The second which I have done recently followed the same basic system but I found that there were so many different choices of hardware and locations to place components like chargers, bus bars that much of it evolved as it progressed. I should also say I got a lot of help and ideas from following threads and asking questions here, This is a very popular topic because so many older boats have rubbish electrics and as you have discovered there are so many potential solutions.
 

Neeves

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A lot of Victron schematics are domestic off-grid, or RV stuff. It would be odd to wire a boat up how you describe, where the charging systems don't work if the isolator is off.
Its interesting - Victron was established when the owner (of the business he established - namely Victron) found a 'gap' in the Marine market for quality electrical equipment. 30 years ago the business was focussed at the marine industry. Now Victron's kit is in every RV retail outlet and the focus does seem to have changed.

Its another example of market power, if you want a better range of product, especially for house domestic product for your yacht, new sink, fridge etc, step outside 'normal' marine retailers and look at the 'Caravan/camping/RV' market/retailers - better range, maybe cheaper prices.

Victron produced a book, manual, one title was 'Electricity on Board', it had another title, I forget. It was available as a free download. I recall that it was in its 9th Edition in around 2013 - and has not been revised. It might be worth the OP's time to check the Victron website and download the manual - it is marine focussed but may not have the latest kit (Lithium was not even a dream in 2013).

Jonathan
 

PaulRainbow

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Think I may have to re think the whole thing then, I was thinking around 300ah lithium and around 400w solar. It’s kind of hard to find decent resource online to plan out a full electrical system
This is key information that should have been in post #1. Much of what has been said in this thread, including several of my suggestions, don't work with Lithium.

400w of solar on a 30ft boat is going to be a squeeze, depending on the boat. A 100w panel is about 1m x 0.5m, do you have room for 4 of those ?
 

Neeves

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This is key information that should have been in post #1. Much of what has been said in this thread, including several of my suggestions, don't work with Lithium.

400w of solar on a 30ft boat is going to be a squeeze, depending on the boat. A 100w panel is about 1m x 0.5m, do you have room for 4 of those ?
300amps of Lithium is roughly equivalent to 600amps of lead. You should be able to run all the domestic loads, galley, fridge, hair dryer - IF you can recharge the battery (and I don't think 400 watts of solar, by itself, is enough if you have an all electric galley).

Note to OP - we don't know your location - maybe you will be located in geography with dependable sun.

Don't be discouraged.

Take on board some of the comments here and use the search function to identify posts on Lithium installations (enough people here have described their lithium builds and their 'lifestyles' (usage of their amps) to provide a solid basis for you). In using the search function and developing a list of useful threads you will find the members who have been there and done that.

Cogitate and start a new thread, or continue with this one, and you will engender a lot of support and help.

Don't drop the hair dryer - a priority on creature comforts goes a long way toward harmony and supporting the investment.

Jonathan
 

Carbalu

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This is key information that should have been in post #1. Much of what has been said in this thread, including several of my suggestions, don't work with Lithium.

400w of solar on a 30ft boat is going to be a squeeze, depending on the boat. A 100w panel is about 1m x 0.5m, do you have room for 4 of those ?
As I said before, I’m new here and apologise for missing information out which is why I’m seeking this advice.

My initial thoughts were 2x175w panels on the arch at the back and another 50/100w panel either on the top of the spray hood or just in front on the deck.

I wanted to look into lithium as has many positive aspects, more usable power, better charging profiles and the obvious less space, weight and number of batteries.
 

Carbalu

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300amps of Lithium is roughly equivalent to 600amps of lead. You should be able to run all the domestic loads, galley, fridge, hair dryer - IF you can recharge the battery (and I don't think 400 watts of solar, by itself, is enough if you have an all electric galley).

Note to OP - we don't know your location - maybe you will be located in geography with dependable sun.

Don't be discouraged.

Take on board some of the comments here and use the search function to identify posts on Lithium installations (enough people here have described their lithium builds and their 'lifestyles' (usage of their amps) to provide a solid basis for you). In using the search function and developing a list of useful threads you will find the members who have been there and done that.

Cogitate and start a new thread, or continue with this one, and you will engender a lot of support and help.

Don't drop the hair dryer - a priority on creature comforts goes a long way toward harmony and supporting the investment.

Jonathan
Thank you for this, not discouraged just a little confused haha, undecided at the moment about the exact number of batteries but most likely 200-300ah of lithium with around 400w solar. Not intending to use an electric galley I am located in the southwest so do get a decent amount of sun in season. I will try searching the site hopefully can find some other useful information, thank you
 

PaulRainbow

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As I said before, I’m new here and apologise for missing information out which is why I’m seeking this advice.
No problem.
My initial thoughts were 2x175w panels on the arch at the back and another 50/100w panel either on the top of the spray hood or just in front on the deck.
Same question as post #34, do you have room (great if you do). Photonic Universe 180w panels :

  • Dimensions: 147.5 x 67 x 3.5 cm
  • Weight: 11.5 kg
I wanted to look into lithium as has many positive aspects, more usable power, better charging profiles and the obvious less space, weight and number of batteries.
An expensive and somewhat more complex installation, but if you need the power......

As mentioned previously, a good place to start would be with what your power usage is likely to be, where you sail, how you sail (day sail, weekends, longer trips, stay in marinas, sit at anchor etc). That will give a good idea of how much storage (batteries) you need and how much charging.

No good having massive storage with inadequate charging, or massive charging capabilities and nowhere to store the power.
 

onesea

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I am no electrician however I am going to put other question in here. This is a 30’ foot boat (assuming sail), the same size as mine.

Have you looked at your water useage? For shower hot and cold water running water. How big are your tanks? I can say from spending a considerable amount of time in a caravan. 2 people with pressurised hot/ cold running water can easily use 40 lts a day. Even then my misses preferred campsite facilities for size and ease and limitless water and power.

So unless your planning on water makers? will need to consider your tankage? How do you plan on heating said hot water?

How much power do you need to run a hair drier for 5 minutes?

How many amps can you realistically get from Solar in the UK summer? How big is your alternator? My thinking is when it’s grey wet and horrible is when people are going to want to use the most power.
I did the basic maths and decided that it was not worth the agro or cost, for us.
We have 100watts of solar (Actually 230watts but one set is always pointing away from the sun), we keep ourselves to a fridge, tablet and phones. No hot and cold running water or hairdryer, if we want 240v or a shower we go to a marina, if we need a clean we boil the kettle.
Our range for cruising is restricted by our need for a shower. Water and fuel we top up as required.

Many will disagree here, do a little Googling see how much extra power you realistically get MMP/ PWM solar chargers in the uk? Is it worth the cost?

My suggestion before designing the wiring system look at what you actually require and can realistically generate.

More equipment means more maintenance, more to break & more cost. If you can afford it an extra 5 or 10 foot gives allot more volume for all the extras. Just remember the costs go up on a square or even cubic not linear with length.

Boats are always a compromise.
 
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