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Chris Pink

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Yep, a built in diesel genny is a must if your power hungry IMHO. Treat the genny as the source of power and the batteries as a buffer. I think most people see batteries as a source.

Totally agree. My boat has a 6kVA genset and I would choose that over any battery-hammering large inverter unit any day. Barge owners on the continent regard a genset as a must have. And as a separate unit rather than an engine driven Travelpack unit - quieter and more fuel efficient. They cost money, but if the boat is your home and you want to spend a lot, if not all, of your time "off the grid" then a thoroughly worthwhile investment.

Edited by Dominic M
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What I found interesting though was the claim that lost capacity in such circumstances will recover (to a degree) if the battery is left without load for a number of hours. This makes sense, as the chemical state within the plates will have a chance to equalise between surface & inner.

 

The notion that Peukert is a short term effect is interesting and quite plausible; some energy will be lost as heat but mostly it is probably a surface discharge effect? I wonder what the recovery time is after returning to a lower drain current?

 

If current (amps) are drawn out of the battery bank faster than the internal chemical conversion can support. Then reducing or disconnecting the load can allow the batteries time to "reform" and claw back some of the missing capacity. Hence the 20 hour and 5 hour discharge capacities will differ.

 

M n M

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If current (amps) are drawn out of the battery bank faster than the internal chemical conversion can support. Then reducing or disconnecting the load can allow the batteries time to "reform" and claw back some of the missing capacity. Hence the 20 hour and 5 hour discharge capacities will differ.

 

M n M

 

NO? Surely the inference is that the 5 and 20hr capacities could actually be a whole lot closer than we have previously believed?.

The 5 hour rate is measured by discharging the battery heavily and continuously till it appears flat (10.8Volts?), which is not typical for most boaters.

 

If we discharged for (say) just one hour at the the 5 hour rate, and then dropped the current draw down to the 20 hour rate, then the battery might have time to recover from its "surface discharge" and so return an overall performance very close to the full 20 hour rate.

 

If I had shore power and a spare battery I would do an experiment!!!!!!!

 

...........Dave

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  • 1 month later...

Starter batteries aren't for living off and neither are leisure batteries.

 

I know a farmer in wales who has a bank of solar panels and 800AH of traction batteries and a diesel generator. he says he has to run genny 2 hours every day. in the summer he can run power tools off the solar battery combination. I believe this all runs his farm and house and there is a large wind turbine that hardly moves too.

 

I would always specify at least a 5000VA inverter, 1000 plus AH battery bank at 24V and prob 500 W of solar panels or more and a diesel generator. If I had that I'd be laughing - I do have 12V 800AH (Trojan 6V batteries) 3000VA inverter and 2.8Kw petrol generator and no solar panels but it's just enough to run this boat with 4 hours charging per day.

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  • 1 month later...

Starter batteries aren't for living off and neither are leisure batteries.

 

I know a farmer in wales who has a bank of solar panels and 800AH of traction batteries and a diesel generator. he says he has to run genny 2 hours every day. in the summer he can run power tools off the solar battery combination. I believe this all runs his farm and house and there is a large wind turbine that hardly moves too.

 

I would always specify at least a 5000VA inverter, 1000 plus AH battery bank at 24V and prob 500 W of solar panels or more and a diesel generator. If I had that I'd be laughing - I do have 12V 800AH (Trojan 6V batteries) 3000VA inverter and 2.8Kw petrol generator and no solar panels but it's just enough to run this boat with 4 hours charging per day.

 

That's one approach. One which will get more and more expensive as fossil fuel prices continue to rise.

 

The other is to try to minimise power consumption, heat water with solar, and use panels for topping up batteries and running the fridge and computer during the day.

 

And insulate well, as you say.

 

George

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  • 2 months later...

Excellent. just ordered a copy.

I'm reading through on line too..............but that's going to take a while. :blink:

I've learned a lot from this forum already so could someone tell me the generally accepted charging regime for cruising?

I've got all the mod cons aboard but run my 6 Kva genny when watching TV, running washing machine etc. I've got 880Ah 12v battery bank, 2k inverter & 80 amp 3 stage charger.

But I've seen somewhere on the forum that running genny for 2 hours daily and 8 hours once a week(?) is the best way to keep batteries in tip top condition. Is this true/ can some one tell me where the info is on the forum so you don't have to repeat it all?

Brilliant forum :cheers: I've spent hours ploughing through all the topics in the last week. Wish I'd known about it years ago :blush:

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Welcome aboard, Swift.

 

There is no single battery management practise that works in all situations, without some serious thought. It depends on the battery type, the charging system and the usage style.

 

Batteries are disposable, whether this comes at 6 months or 10 years depends on you treating them as they need to be treated.

 

First look at all the items connected to the system and determine how much power you consume and for what time. When you know the usage you can work out what it will take to recharge the batteries.

 

Remember that an amphour out needs about 1.1 amphours back in to recharge. Also that batteries self discharge at about 1% per week naturally and this increases as the cells age.

 

Read the victron book, and the smartgauge web site, and Tony Brooks boat training notes -all regularly linked or referred on the forum.

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  • 3 weeks later...

Excellent. just ordered a copy.

I'm reading through on line too..............but that's going to take a while. :blink:

I've learned a lot from this forum already so could someone tell me the generally accepted charging regime for cruising?

I've got all the mod cons aboard but run my 6 Kva genny when watching TV, running washing machine etc. I've got 880Ah 12v battery bank, 2k inverter & 80 amp 3 stage charger.

But I've seen somewhere on the forum that running genny for 2 hours daily and 8 hours once a week(?) is the best way to keep batteries in tip top condition. Is this true/ can some one tell me where the info is on the forum so you don't have to repeat it all?

Brilliant forum :cheers: I've spent hours ploughing through all the topics in the last week. Wish I'd known about it years ago :blush:

 

I think you'll find that was my post. No it's not the best way to keep batts tip top, best way to do that is to fully recharge them every time which involves many hours of charging, which is a bit impractical. My method makes a compromise between cost of fuel used and cost of replacement batts. Running for, say, two hours daily tends to give batts a fast bulk charge only, though this is the best charge efficiency of batts it's not conducive to long battery life, but a regular long absorption charge goes some way to restoring battery condition. We have the same size bank as you and have found this regime to be quite effective though we do have 2.5 times your charging capacity via a large alternator which shortens bulk charge times and we do our absorption charge - 8hrs weekly (ish) - with a genny and Victron combo which though it has quite a large charge capacity, in practice absorption only takes a fraction of that and our digital genny can manage that at tickover which is very frugal on fuel consumption. Of course that regime isn't written in stone as an occasional long cruise can serve as an absorption charge and as batteries age bulk charge takes increasingly less time to reach acceptance voltage necessitating carrying on into absorption for a while. It's all about shifting sands, as batteries age charging regime needs to constantly updated but as its difficult to calculate exactly how to update it's a mixture of gauge watching and instinct, more of the latter in my case.

 

ETA: I judge when to do a long absorption charge by monitoring voltage, when it drops to 12.3 ish (double that in fact as we are 24v) we do It then.

 

ETA further: The Victron book was my first one and though I still consider it to be very good I soon found out that the author's advice to cycle between 80% and 30% SoC with a monthly equalisation charge will rapidly shorten batt life, though charging to 80% SoC is bulk charging which does give rapid charging. I found going down to about 50% to 60% SoC with a weekly equalisation/absorption to be far more realistic, I suspect the author was basing his findings on using top of the range AGMs, particularly Victron ones, instead of the less expensive choice of us ditch crawlers.

Edited by nb Innisfree
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Charles Sterling once had an interesting document on his website (now removed unfortunately) the essence of which was the only batteries worth buying are wet lead acid that you can top up, which are the cheapest batteries. These days engine start batteries are little or no different from so-called leisure batteries, because modern vehicle batteries are still running equipment when the car is parked. I am sure I remember Gibbo some years ago writing that he had taken apart some modern "leisure" batteries, and that there was no discernible difference in plate thickness to modern starter batteries.

 

So £1k for batteries sounds like an unnecessary amount to spend. It appears that the price difference between ordinary start batteries (non-sealed) and "leisure" batteries is the use of the word, "leisure."

As a liveaboard nearly continuous cruiser (summer) my batteries are important to me. Some may say I'm paranoid about them. When I designed the electrical system on our boat we decided to go for mains powered most things. At the time my understanding of battery use and limitations was almost non existent, but I soon learned.

I now have nearly £2k of batteries on our boat. 2X 210 amp Lifelines as a second domestic bank = £1k, and 12V 900Amp/hr of traction cells as the main domestic bank. Cost £900.00. So £1000 for batteries isn't OTT.

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  • 4 weeks later...
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  • 2 months later...

As an ex yottie I have some fairly strong views on what I want when I get my boat (hopefully soon) and one of the things I want is a generator. The marine ones are ***king expensive and the petrol suitcase jobbies seem to be **** dangerous. However after moseying through ebay I came across this:

 

Silent Diesel

 

Air cooled, diesel, silent, 6.3 kv and not that big - although there are smaller ones also. Anyone tried/used/know about this sort of solution. Can't see why room couldn't be found in a canal boat and they're £700 rather than £4000!

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As an ex yottie I have some fairly strong views on what I want when I get my boat (hopefully soon) and one of the things I want is a generator. The marine ones are ***king expensive and the petrol suitcase jobbies seem to be **** dangerous. However after moseying through ebay I came across this:

 

Silent Diesel

 

Air cooled, diesel, silent, 6.3 kv and not that big - although there are smaller ones also. Anyone tried/used/know about this sort of solution. Can't see why room couldn't be found in a canal boat and they're £700 rather than £4000!

Might be silent but at 171kg its bloody heavy!

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As an ex yottie I have some fairly strong views on what I want when I get my boat (hopefully soon) and one of the things I want is a generator. The marine ones are ***king expensive and the petrol suitcase jobbies seem to be **** dangerous. However after moseying through ebay I came across this:

 

Silent Diesel

 

Air cooled, diesel, silent, 6.3 kv and not that big - although there are smaller ones also. Anyone tried/used/know about this sort of solution. Can't see why room couldn't be found in a canal boat and they're £700 rather than £4000!

Its only 2 Kw per phase. I wouldn't want to wire a narrowboat for 3 phase

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You will be lucky to get 1000 hours out of it.

 

They are for occasional use only.

 

Oh & I would bet that what they call silent is not actually any where near it, not even quiet or acceptable never mind silent.

 

 

We have a similar but much better unit (P6000s) that uses the genuine Yanmar L100 that these types all have clones of. The real engine will do 3-4000 hours before major work. The p6000s is almost silent at 59dba @ 7m. They are no no longer available apart from old stock as they have gone bust. They also cost the best part of £3k

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As an ex yottie I have some fairly strong views on what I want when I get my boat (hopefully soon) and one of the things I want is a generator. The marine ones are ***king expensive and the petrol suitcase jobbies seem to be **** dangerous. However after moseying through ebay I came across this:

 

Silent Diesel

 

Air cooled, diesel, silent, 6.3 kv and not that big - although there are smaller ones also. Anyone tried/used/know about this sort of solution. Can't see why room couldn't be found in a canal boat and they're £700 rather than £4000!

 

I have worked with all types of generators from the mid-eighties any thing that is air cooled will not be silent

 

Keith

Edited by Keith M
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Oops sorry I wasn't pointing at the one in the link necessarily rather at the concept - as opposed to suitcase petrol ones or very expensive marinised ones. This is the company that were advertising on ebay: Direct Equipment Sales

They have some with Yanmar engines and also cheaper single phase ones. If the cheaper one only lasts a couple of years then at less than a grand surely its got to be worth considering. And yes I realise they aren't silent but 70db is pretty good.

My question was has anyone had experience of going down this route?

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There's a trip boat with one of those Suntom gennies and I can assure you wouldn't want it on a liveaboard boat.

 

If you really want to go down the inboard route you should look at cocooned water-cooled generators but they aren't cheap.

 

I know someone who has the water-called Beta generator but not the cocoon option and although that's bearable inside if you're doing noisy stuff, it is pretty loud. I think missing the cocoon option was a mistake. It's louder than their Beta propulsion engine which is a little surprising but i wonder whether that's because it's mounted higher (on the swim of a wide-beam)

Edited by Chris Pink
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There's a trip boat with one of those Suntom gennies and I can assure you wouldn't want it on a liveaboard boat.

 

If you really want to go down the inboard route you should look at cocooned water-cooled generators but they aren't cheap.

I guess I was thinking of putting on deck somewhere - maybe under some form of cover when not in use. Below decks I don't think it would get enough cooling.

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I guess I was thinking of putting on deck somewhere - maybe under some form of cover when not in use. Below decks I don't think it would get enough cooling.

 

The trip boat has the Suntom on the rear deck. Even if you could live with it your neighbours wouldn't.

 

I'm not sure where the term 'silent type' has come from because they certainly aren't. the dB figure should have a distance and is logarithmic, ie 72dB is a factor louder than 60dB, not 18%.

 

I think you need to hear them on site and working to get a feel for it.

 

There is no doubt that the quietest generators are the 2KVA suitcase inverter types or the fully cocooned water-cooled types.

 

And even they are stretching the definition if they are described as silent.

 

Noise in the abstract is a difficult thing to assess. In the middle of the morning a lot more noise is acceptable than in the early evening.

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I guess any form of power generation is going to make noise - I have plenty of experience of that from my yachting days - where I had solar and a wind generator and still wished I had a genny. I am just trying to weigh up the issues of cost/noise/convenience/safety.

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