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Electrics from scratch for sail away - Advice


jono2.0

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Hello,

 

First post here so please be gentle! haha

 

OK, I'm literally weeks away from getting my 60' sail away. I will be a continuous cruiser liveaboard and regularly moving around the canal and river waterways. Engine is a Canalline 42 with 1x 50A and 1x 175A Alternators. I'm planning on getting a Webasto water heater/boiler too to compliment multi fuel stove.

 

I have done some sums and require around 120Ah a day for things like, 12v fridge, pumps, boiler, laptop, TV, lighting, phone charging etc. (Actual is 80Ah but I wanted a good amount of wiggle room).

 

I'm planning on filling my roof with solar and would like to use Victron equipment (apart from solar).

 

I'm planning on:

5x 285w Monocrystalline Solar Panels totalling: 1425w (It has an approx 42' cabin / roof space)
1x Victron SmartSolar 100A MPPT Solar Charge Controller
1x Victron BMV-700 Battery Monitor
1x Victron SmartSolar LCD display
1x Victron Multiplus 1600VA Inverter 70A charger 16A relay 12V
I'd like to use solar as much as possible to power my needs but haven't decided upon batteries just yet.
I'd like your comments on qty and type of batteries I'd need to keep everything tip-top, if I'll need a generator for the winter months (likely Honda EU2.0i using LPG).
Is the above all too overkill or will I struggle in the depths of dark winter? I would like to use a washing machine every so often but if batteries would get hammered I can use Generator for that. (obviously not on hot washes).
I'll be getting an electrician to do the install (apart from solar panels on the roof).
Thanks Jono
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Doing some quick sums the solar charger in my opinion is under sized

 

The panel can produce around 125 amps

 

 

Keith

With out a doubt the one controller will not cope. I would aim for two strings of 3 panels through two separate controllers if you must have the Victron.

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If planning on running a washing machine via the inverter, then it is undersized.

 

Remember that 1600Va is not 1600 watts.

You only get one chance at the 'fit out' so over engineer and ensure it is 'future-proof'.

 

If you only intend to run it via the genny, then it may not be a problem.

 

You may not plan on a freezer, toaster, electric kettle, deep fat fryer, hair-dryer, etc etc, but a 'bigger inverter' will not use any more power from the batteries than one a bit smaller, and when you decide to add further appliances (or sell the boat) then you can be sure that your system will cope.

 

Just as an aside, 80Ah per day is quite a 'frugal usage'. Don't forget that in the Winter when your solar is producing 5% of its Summer output, you have maximum demand on your batteries 15 hours per day of darkness, heating on for longer, watching TV / on computer for longer etc.

Recalculate at 'worst case' and see what you get.

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Doing some quick sums the solar charger in my opinion is under sized

 

The panel can produce around 125 amps

 

 

Keith

 

How do you work that out? 1425w at 125A is only 11.4v, so unless the batteries have been completely flattened I find it hard to see how the current could be that high. And do solar panels ever actually give out their rated output in the U.K?

 

Anyway I think it is hard to have too much solar during the depths of winter, with short days and, if you are lucky, about 10% of max output.

 

For me the inverter is a bit undersized and might fail to start some devices like a vacuum cleaner. Also, any plans for a washing machine? In which case it is definitely undersized. If you get a 3000VA one it doesn't mean you have to use 3kw and flatten your batteries, but it is available for short bursts of high power e.g. an electric kettle when the engine is running, starting up devices with motors etc.

 

On the BMV-700 these are useful for measuring current and AH in and out, however the SoC indication has to be taken with a pinch of salt as the device presumes the battery's capacity is whatever you have entered (ie the capacity on the batteries' label) but the reality is that the actual capacity is likely to fall off and thus the SoC will potentially over-read and give you a false sense of security. I recommend a Smartgauge as well, this will allow you to keep an eye on the health of your batteries. Without it, the sort of scenario you might end up with is lights going out whilst the BMV SoC is reporting 80%. This is what happened to some friends of mine who didn't realise that the capacity of their batteries had fallen to virtually nothing, until the lights went out!

 

I appreciate that I'm adding to your bill but in the context of a new build these are not great costs!

 

Based on my poor experience with leisure batteries, I'd recommend semi-traction batteries such as Trojan T105s. Based on your expected AH usage you probably only need 450AH -worth (4 batteries) but if you have room and budget you might find 675AH - worth (6 batteries) gives you more flexibility when sunny winter days only come by infrequently.

 

As is often said in here, with abuse you can kill good batteries just as fast as you can kill cheap batteries but if you have adequate charging and monitoring equipment from the outset, there's no reason to abuse the batteries!

With out a doubt the one controller will not cope. I would aim for two strings of 3 panels through two separate controllers if you must have the Victron.

I don't understand this, how can the panels produce more than 100A at charging voltage for anything other than exceptional circumstances?

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For me the inverter is a bit undersized and might fail to start some devices like a vacuum cleaner. Also, any plans for a washing machine? In which case it is definitely undersized. If you get a 3000VA one it doesn't mean you have to use 3kw and flatten your batteries, but it is available for short bursts of high power e.g. an electric kettle when the engine is running, starting up devices with motors etc.

 

 

 

 

The OP has stated he will be having a washing machine, but will be 'disconnecting' the heater so he can run it of a Honda Generator

This seems to be a rather retrograde step when. by 'doing it right' in the first place allows you to use equipment as it is intended.

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I fitted Innisfree with 1x Victron 24-70-3000 Multiplus, 8x 120ah AGMs, 1x 24v 100 amp alternator, 1x 12v 70 amp alternator for starter batt, BMV 501 monitor and a Smartgauge. Full size domestic w/m, 240v lighting and various 240v appliances. Used approx 70ah daily (100ish on washing day) 3kva Victron proved useful giving a good margin for appliances. Remember all amp/ah figures need doubling if on 12v.

 

Daily bulk charge to approx 80% SoC and a weekly 8 hr raised absorption charge from Victron and Kipor 2kva genny. No solar (useless in the winter anyway) but it all worked very well.

 

ETA: W/m used built in heater.

 

Also edited some a/h figures

Edited by nb Innisfree
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The OP has stated he will be having a washing machine, but will be 'disconnecting' the heater so he can run it of a Honda Generator

This seems to be a rather retrograde step when. by 'doing it right' in the first place allows you to use equipment as it is intended.

Yes I missed that. It would be sensible to do the washing whilst cruising and let the 175A alternator take most of the load during the heating phase of the wash cycle. This only lasts 20mins or so and then the remaining cycle time is much lower power consumption, (rinses, spinning) which the batteries can easily run if necessary.

 

To the OP have you considered a tumble drier? I know most folk don't have them but we do and it is great since I hate having wet washing draped all over the place. We have a compact vented one. It is also great just for putting your wet jeans etc in when you've been caught out boating in the rain without adequate waterproofs! Again, it uses 2kw which is roughly 175A and so we just put it on when cruising so it doesn't deplete the batteries.

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This is all great, exactly why I read this forum virtually daily!

 

nicknorman - yes I'd love to have a tumble drier and with me motoring around lots it would be ideal to do washing drying etc when driving.

 

I think 5x 285w solar is the max I can have on the roof so lets leave that as is.

 

Looking at Victron. Instead of having multiple bits of kit with 2x MPPT's etc. What do you think of the idea of one mega unit:

 

Victron Easy Solar 3000VA Inverter/Charger
Victron Colour Control GX

SmartGauge battery monitor

 

That effectively has 2x MPPT's built in and it would be beefy enough to cope with washing / drying (not at the same time of course).

 

Only concern is how to use alternator in this kit?

Edited by jono2.0
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Mastervolt has similar products

 

Also look at the continuous ratings of victron products

 

Victron has just issued a new price list

 

Keith

Hi Keith, you are of course biased since you are a MV agent. HOWEVER you are in my opinion quite right to imply that MV makes the better and more reliable product:-)

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This is all great, exactly why I read this forum virtually daily!

 

nicknorman - yes I'd love to have a tumble drier and with me motoring around lots it would be ideal to do washing drying etc when driving.

 

I think 5x 285w solar is the max I can have on the roof so lets leave that as is.

 

Looking at Victron. Instead of having multiple bits of kit with 2x MPPT's etc. What do you think of the idea of one mega unit:

 

Victron Easy Solar 3000VA Inverter/Charger

Victron Colour Control GX

SmartGauge battery monitor

 

That effectively has 2x MPPT's built in and it would be beefy enough to cope with washing / drying (not at the same time of course).

 

Only concern is how to use alternator in this kit?

 

I note you've replaced the BMV with a Smartgauge. I would only dispense with the BMV if the Victron gadget includes a means of measuring the total current in and out of the batteries, ie has a shunt, which I don't think it does? You need a Smartgauge plus a means of measuring current and AH in/out of the batteries.

 

Regarding the alternator you would just use it as normal. If the batteries were low and/or there was a lot of power demand when motoring, the solar and alternator will work happily together and both provide current. If the load is light then the devices will start to reduce current in accordance with their target charging voltage. The alternator has a fixed voltage but the solar presumably is configurable so by setting the solar charger voltage a little above the alternator's voltage you can engineer it so the alternator reduces its current first, to a large extent anyway.

 

Oh and on the "one mega unit" thing there are 2 schools of thought, one is that having all your eggs in one basket is regretted when the device goes faulty, the other is that it makes for a neat and "joined up" system. A matter of personal choice.

Edited by nicknorman
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Hi Keith, you are of course biased since you are a MV agent. HOWEVER you are in my opinion quite right to imply that MV makes the better and more reliable product:-)

 

I will also supply Victron at realistic prices as well

 

I am happy to supply either product

 

And also good quality installation products

 

Keith

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Doing some quick sums the solar charger in my opinion is under sized

 

The panel can produce around 125 amps

 

As long as the panels are not configured to go over the max voltage of the Victron then it doesn't matter to the Victron, it will only output a max of 100amp but it doesn't care if the input is 125amp.

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