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DasDsm

Generation Decision

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Hey,

Can't see an existing topic on this and wondering if you had three options what would you choose and why?

We will be continuous cruisers and moving a fair number of days per week although will enjoy stopping for longer periods at certain points.  We've not done a full power audit but will probably get 2 days from the current 400ah AGMs.

Due to work commitments we have a bit more of a reliance on 240v power so need to at least have a good store or be able to generate it easily. 

If you had a choice of installing these options what would be your preference. 

1. Install a good amount of solar (900w) using existing 400ah AGM which are in fair condition. Charge using these in summer and then use the alternator (Beta 43 175amp alt) on the engine in winter or when stopped for longer periods of time.

2. Do the same as above but upgrade batteries to Lifepo4 to allow bigger storage capacity and quicker charging. 

3. Install travel power unit or a small silenced generator. Rather than options 1 or 2. 

Maximum budget of about £5k

Thanks!

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When you say " we havent done a power audit " do you actually mean " we cant be bothered to do a power audit "? . It sounds like theres more than one of you so im at a loss as to why you would not do one . I expect that without doing one you are going to be guessing about how to go about achieving what you want . Worse than that youre asking the forum to guess aswell . 

So do a power audit or youre asking for trouble . 

" due to work commitments ....  reliance on 240 v " . This comment could only  be more vague , if you wrote the same sentence in swahili or Thai . So what items r u referring to as it could be anything from a camera , a computer - to a number of growlights for a floating weed cultivation business . 

You will find you get little response unless youre more specific .

This isnt meant harshly , its largely a bit tongue in cheek but the there is no " one size fits all " answer when it comes to boat electrics , power generation & battery requirements . Without the numbers theres nothing to crunch 

Not that i can help with spefics but the folk that can will NEED them 

cheers

 

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Forget about portable gennies, you’ll hate having to set up every other day.  Solar is good for summer.    Just seen you have a decent alternator,  I would get solar first it will have the biggest impact.   A alternator controller is best for bigger alternators so you may want to look at this option then a travel power.  

 

Lifepo4 are good but spend the money on generating the power first.   If you don’t generate power in winter then lifepo4 are a waste of money as solar keeps any battery topped up.

Edited by Robbo
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I would guess that about 450W of solar would be ok for the 100Ah that you estimate you will be using on a daily basis.  This is based on 400Ah of batteries discharged no lower than 50% (so 200Ah of usable capacity) lasting two days.

Going up to 900W of solar will be of little benefit for most of the summer and may extend the season of being solar self sufficient by maybe a month.  So I would save the money and put the savings into your other charging method.  To recharge your batteries is going to take a long time, but first off you need to do the power audit, or everything is just a guess.

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33 minutes ago, chubby said:

When you say " we havent done a power audit " do you actually mean " we cant be bothered to do a power audit "? . It sounds like theres more than one of you so im at a loss as to why you would not do one . I expect that without doing one you are going to be guessing about how to go about achieving what you want . Worse than that youre asking the forum to guess aswell . 

So do a power audit or youre asking for trouble . 

" due to work commitments ....  reliance on 240 v " . This comment could only  be more vague , if you wrote the same sentence in swahili or Thai . So what items r u referring to as it could be anything from a camera , a computer - to a number of growlights for a floating weed cultivation business . 

You will find you get little response unless youre more specific .

This isnt meant harshly , its largely a bit tongue in cheek but the there is no " one size fits all " answer when it comes to boat electrics , power generation & battery requirements . Without the numbers theres nothing to crunch 

Not that i can help with spefics but the folk that can will NEED them 

cheers

 

Thanks for the response and sorry that I was not able to give concrete information as pretty new and just wanted to get some general views from the users on here.

We've not had time to do a full power audit as we've not started to live-aboard the boat full time and it's also looking to get some actual usage data over time from the measurement equipment we have on board. 

I understand that there are so many variable and I wasn't necessary going to make major decisions just based on this information so maybe I shouldn't post this sort of requests here then unless it's backed by hard facts. 

Thanks for the advice. 

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3 minutes ago, Chewbacka said:

I would guess that about 450W of solar would be ok for the 100Ah that you estimate you will be using on a daily basis

100Ah per day is not a 'large' usage - in fact is quite low, particularly for a liveaboard CCer who has "work requirements requiring 'mains' 230v"- I wonder if the OP thinks that his 400Ah batteries will allow him to use 400Ah (200Ah per day)

 

I echo the thoughts that the OP needs to do a proper power audit, and maybe enlighten us as to his electrical (battery) experience & knowledge.

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2 minutes ago, Alan de Enfield said:

100Ah per day is not a 'large' usage - in fact is quite low, particularly for a liveaboard CCer who has "work requirements requiring 'mains' 230v"- I wonder if the OP thinks that his 400Ah batteries will allow him to use 400Ah (200Ah per day)

 

I echo the thoughts that the OP needs to do a proper power audit, and maybe enlighten us as to his electrical (battery) experience & knowledge.

Thanks Alan,

Don't worry I know about the depth for discharge so will only get about 200Ah and will be doing a full power audit once living aboard as then would have a better idea of frequently of use of equipment. 

Thanks. 

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7 minutes ago, DasDsm said:

Thanks Alan,

Don't worry I know about the depth for discharge so will only get about 200Ah and will be doing a full power audit once living aboard as then would have a better idea of frequently of use of equipment. 

Thanks. 

Unless a 'newbie' gives some background to their knowledge levels it can come over that board members are either condescending or teaching their grandmother to suck eggs.

It is normally better to assume a zero knowledge so at least the 'thread starter' can pick up from where they are comfortable.

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Also, use less power. candles and paraffin for lighting are possible, LED's, small TV, obvious really  and you probably do that anyway, fridge in summer but not in winter, we turn our off at night sometimes and its only a little fridge. As far as making electric solar is good, more the merrier but I would keep an eye open for a generator, they are bothersome and I would only ever run one on the bank but I think the advantages just about outweigh the bother (but only if its cheap, v.portable, diesel and you've got somewhere to put it) 

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7 minutes ago, Bee said:

Also, use less power. candles and paraffin for lighting are possible, LED's, small TV, obvious really  and you probably do that anyway, fridge in summer but not in winter, we turn our off at night sometimes and its only a little fridge. As far as making electric solar is good, more the merrier but I would keep an eye open for a generator, they are bothersome and I would only ever run one on the bank but I think the advantages just about outweigh the bother (but only if its cheap, v.portable, diesel and you've got somewhere to put it) 

Paraffin and candles for lighting! Another fire to add to the statistics. 

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Yes you ought to do the power audit etc. etc. But the upshot of many previous threads on the subject is that a decent amount of solar will meet all of your power needs for 6-8 months of the year, but will deliver next to nothing in the winter months. For this there is no easy answer (other than taking a mooring with shore power available). Keeping your batteries topped up by generator, whether that is your main engine and alternator, a travel power or a petrol powered generator, will require you to have the engine/generator running for hours. 

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Allow 150 ah per day and you are nearer the mark, so for two days this will need 600 ah bank, but that is when batts are new, as capacity drops even 600 ah can struggle. On Innisfree we had a larg alternator (100 amp @24v which equals 200amp @12v) and 8x120ah batts, might sound like overkill but there were no power issues with that   ( I do like a sledgehammer for cracking the odd nut then I needn't worry about coconuts)  We averaged about 70ah (140ah @12v) per day, two full auto machine washes per week pushed that average to 80ah (160ah@12v) per day. 

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1 hour ago, DasDsm said:

Thanks for the response and sorry that I was not able to give concrete information as pretty new and just wanted to get some general views from the users on here.

We've not had time to do a full power audit as we've not started to live-aboard the boat full time and it's also looking to get some actual usage data over time from the measurement equipment we have on board. 

I understand that there are so many variable and I wasn't necessary going to make major decisions just based on this information so maybe I shouldn't post this sort of requests here then unless it's backed by hard facts. 

Thanks for the advice. 

As i say , my comments were a bit tongue in cheek - just come back with a few more details about your expected usage if you are uncertain about it & folk on here will be very helpful . Ive always found it so . Maybe stating what kind of equipment , specific if possible etc . 

Those in the know about electrics , battery charging etc can then go about giving advice which will prove very useful , so do come back with as much info as u can 

cheers

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15 hours ago, DasDsm said:

 

If you had a choice of installing these options what would be your preference. 

1. Install a good amount of solar (900w) using existing 400ah AGM which are in fair condition. Charge using these in summer and then use the alternator (Beta 43 175amp alt) on the engine in winter or when stopped for longer periods of time.

2. Do the same as above but upgrade batteries to Lifepo4 to allow bigger storage capacity and quicker charging. 

3. Install travel power unit or a small silenced generator. Rather than options 1 or 2. 

Maximum budget of about £5k

I think there is enough info there to give 'some' help.

Option 1. The best of the 3. Maybe 500w of solar in the summer is all you need but 900W will give you more in the spring and autumn. I would go for 6-700Ahrs so you are not cycling so deeply. The batteries will be happier if on a big inverter load. Problem then as others say is the winter. Need to find some shore power.

Option 2. Yea, sounds great but do you want to go first? For me the big bonus - I hear - is that they will charge quicker to 100% so maybe only 2 hours running of engine a day in winter....to be proven!......but what about below zero temps. Efficiency goes out the window and they die if you charge them. You die if they go on fire. Some expensive mistakes in the offing. I am watching. I will switch but I'm not going first. 

Option 3. Years of lumpy water sailing tells me an installed diesel genny is the way to go, coupled to Option 1. This is my favored option but out of your budget and mine.

All the above based on 100-150Ahrs use per day which is pretty typical.

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42 minutes ago, Dr Bob said:

Option 2. Yea, sounds great but do you want to go first? For me the big bonus - I hear - is that they will charge quicker to 100% so maybe only 2 hours running of engine a day in winter....to be proven!......but what about below zero temps. Efficiency goes out the window and they die if you charge them. You die if they go on fire. Some expensive mistakes in the offing. I am watching. I will switch but I'm not going first. 

 

My thinking too on LiFePO4 batteries. There are a few of people around on here who say they are the bee's knees and won't hear a word said against them, but none of these evangelists ever happen to actually have them installed in a liveaboard.

The nearest we have got is a chap who actually dipped his hand in his pocket and ordered two last year. One arrived promptly but it is still in it's box unused while he continues to wait for the other. 

Like Dr Bob, I'm dead keen to encounter someone who actually has and uses them in real life before buying some. Unicorns seem more commonplace than LiFePO4 users. 

Edited by Mike the Boilerman
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As above, I'm very interested in the stated advantages of LiFePO4 batteries - particularly the reduced recharge times and lack of sulfation if not fully charged daily. However I'd like to see some real world experience of these by someone else first!

As to your budget, I should think you can get a decent solar setup and still have significant spare change for other options/ upgrades.  Don't forget some form of battery monitoring if you don't already have it. 

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1 hour ago, Dr Bob said:

I would go for 6-700Ahrs so you are not cycling so deeply.

OP needs to understand this fully. The extra capacity is not intended to allow more time between charges, it’s intended to allow a shallower depth of discharge between charges. 

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53 minutes ago, Tom and Bex said:

As above, I'm very interested in the stated advantages of LiFePO4 batteries - particularly the reduced recharge times and lack of sulfation if not fully charged daily. However I'd like to see some real world experience of these by someone else first!

I'm planning on LifePo4's,  I've seen a few "Youtuber boaters" have them installed already.    As one of the main advantages of LifePo4 is many cycles (3000-5000) it will be a while before you get any real long term real world experience of them.

Edited by Robbo

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4 minutes ago, WotEver said:

OP needs to understand this fully. The extra capacity is not intended to allow more time between charges, it’s intended to allow a shallower depth of discharge between charges. 

 

I don't understand the point of this. Surely it is better to discharge to 50%-ish, as recharging is quicker. 

I mean putting 200AH back into a 400AH bank is going to be quicker than putting 200AH back into an 800AH back Shirley, as more time will be spent in bulk charging and less in absorption.

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2 hours ago, Dr Bob said:

I think there is enough info there to give 'some' help.

Option 1. The best of the 3. Maybe 500w of solar in the summer is all you need but 900W will give you more in the spring and autumn. I would go for 6-700Ahrs so you are not cycling so deeply. The batteries will be happier if on a big inverter load. Problem then as others say is the winter. Need to find some shore power.

Option 2. Yea, sounds great but do you want to go first? For me the big bonus - I hear - is that they will charge quicker to 100% so maybe only 2 hours running of engine a day in winter....to be proven!......but what about below zero temps. Efficiency goes out the window and they die if you charge them. You die if they go on fire. Some expensive mistakes in the offing. I am watching. I will switch but I'm not going first. 

Option 3. Years of lumpy water sailing tells me an installed diesel genny is the way to go, coupled to Option 1. This is my favored option but out of your budget and mine.

All the above based on 100-150Ahrs use per day which is pretty typical.

This is similar to my own thoughts.  The solar can be all had for a few hundred quid but the diesel genny is likely to blow your budget.  Reducing your consumption is important too.  For about two years I was moored on a permanent mooring with no hook-up and no solar and I worked full-time until late each day.  My engine alternator is 70a and, at that time, it was playing up so didn't charge very well.  My cheap solution was to buy a basic 1000w suitcase genny from Gumtree for £50.  Every couple of days I would put some petrol in it, set it running at just after 8.00am and go to work (my neighbour would keep an eye on it).  When I got home, the genny would have run dry hours earlier and my batteries would be all perky, having been charged for about 4-5 hours through a 40a Sterling charger.  Then I would use the bare minimum of power.  No TV, laptop/phone charged while at work etc.  

Point is,  I made it work, until I decided to upgrade to a fancier genny and sold the old one to a forum member for £40.

An earlier poster on this thread discounted portable gennies, but I totally disagree.  If you have the funds and space for a cocooned diesel genny, then fine, but otherwise a portable will take all the wear and tear off your engine, and, importantly, give you another way of charging your batteries. 

So that's what I would do if I were you.  Get solar and a portable, and save up for an installed diesel genny.

 

 

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57 minutes ago, Mike the Boilerman said:

I don't understand the point of this. Surely it is better to discharge to 50%-ish, as recharging is quicker. 

I mean putting 200AH back into a 400AH bank is going to be quicker than putting 200AH back into an 800AH back Shirley, as more time will be spent in bulk charging and less in absorption.

To answer the first point, look at the cycle life vs DoD curve of any battery. The difference in life between 75% DoD and 50% DoD is significant. 

As regards your second point, no, quite the opposite. The time taken in absorption will be the same for both sets of batteries whereas the time spent in bulk will be greater for the more deeply discharged bank. Always assuming that a large enough charge source is available of course. 

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3 hours ago, Dr Bob said:

I think there is enough info there to give 'some' help.

Option 1. The best of the 3. Maybe 500w of solar in the summer is all you need but 900W will give you more in the spring and autumn. I would go for 6-700Ahrs so you are not cycling so deeply. The batteries will be happier if on a big inverter load. Problem then as others say is the winter. Need to find some shore power.

Option 2. Yea, sounds great but do you want to go first? For me the big bonus - I hear - is that they will charge quicker to 100% so maybe only 2 hours running of engine a day in winter....to be proven!......but what about below zero temps. Efficiency goes out the window and they die if you charge them. You die if they go on fire. Some expensive mistakes in the offing. I am watching. I will switch but I'm not going first. 

Option 3. Years of lumpy water sailing tells me an installed diesel genny is the way to go, coupled to Option 1. This is my favored option but out of your budget and mine.

All the above based on 100-150Ahrs use per day which is pretty typical.

Thanks Dr Bob.

Its a given I will be installing solar and am really interested in Lifepo4 and the budget I have could probably stretch to a solar install and about 360ah of Lifepo4.  The lure of fast charging, cycles and DoD is a good sell even if the initial cost is very high. I'm doing some further reading on the differences between Lifepo4 and standard Lithium-Ion as Lifepo4 are designed to be much more stable and safer than your normal mobile battery etc.

The boat already has a Mastervolt combi with good monitoring systems and used to have a Mastervolt Whisper generator but this got removed so be interesting to see if this makes it cheaper to reinstall a new unit if the connections are still there.

Thanks for the thoughts.

3 hours ago, Mike the Boilerman said:

 

My thinking too on LiFePO4 batteries. There are a few of people around on here who say they are the bee's knees and won't hear a word said against them, but none of these evangelists ever happen to actually have them installed in a liveaboard.

The nearest we have got is a chap who actually dipped his hand in his pocket and ordered two last year. One arrived promptly but it is still in it's box unused while he continues to wait for the other. 

Like Dr Bob, I'm dead keen to encounter someone who actually has and uses them in real life before buying some. Unicorns seem more commonplace than LiFePO4 users. 

I think the difficulty is also trying to buy the thing as not many people sell the large ah capacity.  The only ones which seem to be in stock ate stupidly more expensive than the rest.

If I do get some I'll let you all know how it goes..

2 hours ago, Tom and Bex said:

As above, I'm very interested in the stated advantages of LiFePO4 batteries - particularly the reduced recharge times and lack of sulfation if not fully charged daily. However I'd like to see some real world experience of these by someone else first!

As to your budget, I should think you can get a decent solar setup and still have significant spare change for other options/ upgrades.  Don't forget some form of battery monitoring if you don't already have it. 

Thanks!

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1 hour ago, DasDsm said:

Its a given I will be installing solar and am really interested in Lifepo4 and the budget I have could probably stretch to a solar install and about 360ah of Lifepo4.  The lure of fast charging, cycles and DoD is a good sell even if the initial cost is very high. I'm doing some further reading on the differences between Lifepo4 and standard Lithium-Ion as Lifepo4 are designed to be much more stable and safer than your normal mobile battery etc.

I'm looking at Victron LifePo4's for when my current batteries give up the ghost.   Relion's tend to have a limit of 100amp discharge/charge per battery even for the larger ones.     As my Victron Multi is old and only 2000watt I will be going for the BMS 12/200 for the BMS.

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51 minutes ago, Robbo said:

I'm looking at Victron LifePo4's for when my current batteries give up the ghost.   Relion's tend to have a limit of 100amp discharge/charge per battery even for the larger ones.     As my Victron Multi is old and only 2000watt I will be going for the BMS 12/200 for the BMS.

Ah thanks for that Robbo, had not noticed that about the Relion so will check that again as they are the most keenly priced of the Lifepo4 manufacturers. 

The Mastervolt batteries are eye wateringly expensive when compared to the other brands too. 

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