running engine to charge battery

[Goldie]

I had a neighbour who ran his engines who produces an almighty stench fron old engines, to the point that I had to vacate my boat till at least half an hour after he had finished. He should either have plugged in, or gone to sea. He applogised afterwards, everytime, but never stopped him doing it.

There was an incident when a boat insisted on engine running - despite requests not to -when on a Newtown creek mooring a year or two ago. The fumes were blowing straight into the adjacent boat and the lady aboard had to be medically evacuated - I think it was reoported in a letter to either PBP or YM at the time.

I think the answer is consideration. If you're the only boat around then by all means run as and when you wish. If in a populated mooring area or anchorage, morning sounds good to me. When all's said and done, if you're moving on or just arrived, charging will happen as a matter of course. If you're staying the day, then you can run engines at an acceptable hour anyway.

 

[Bilgediver]

Just a thought but I, occasionally, move in lorry driving circles. There the received wisdom is quite the oposite and drivers will happily leave an engine on tickover for an hour or so (although recent fuel price increases has downturned this a little)

The typical engine would be circa 9.5L and around 300hp or 12L around 420hp

Lorries typicaly do 500 - 1000k miles with little more than regular oil/filter changes (call that 15,000 - 30,000 hours very aprox)

Thoughts ?

No chance of many marine diesels for the leisure industry achieving those hours. due to rating and material differences.

We had a dickens of a job getting Volvo to agree to us fitting a leisure engine in a safety boat for use in the north Sea. They wanted it derated to industrial rating!!!!!!!! We pointed out that it sat in davits most of its life and might go in the water once a week for 30 minutes. I believe to was a TAMD 40 something. It gave good service for many years while we still operated the rig. It would have been a different story if operated at the leaisure rating in a work boat 24/7!

Some of the bigger diesels are derivatives of truck engines however on these baots they have diesel alternators fitted which have engines as big as the propulsion on many yachts .

 

[Jamesuk]

Generally speaking you need to spin the alternator in the 1,300-1,500rpm range to get full whack flowing out of it.


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I always run a little Dufour 30 at 1300-1500 RPM mainly because the Fridge and a night of sleeping with a fan and a light on drains the battery - I also run at 1500RPM when using the Anchor Windless otherwise without the charge the windless trip switch will go.

 

[Touchwood]

This strikes a chord with me as a frequent Norfolk Broads sailor - the Hullabaloos (cf. Arthur Ransome) who return to their hire cruiser at 11:00 pm from the pub and proceed to run their engine for an hour or so - presumably because they are worried their batteries won't stand having all the boat lights on until the early hours of the morning. Gah - just a rant - sorry

 

[Elemental]

We were tied up in Tarbert one balmy evening many years ago. We had put our kids to bed and were sitting in the cockpit waiting for them to get to sleep, another boat came in and rafted up to us, pulled a petrol generator out of a locker, started it in their cockpit and then cleared straight off to the Frigate. We were suffering miserably when a guy from a boat in the trot in front came across our deck with a big bucket, it took two bucketfuls to permanently silence it, but in 1/2 hr. the cockpit was dry again, all evidence gone and we were having a drink with our new friends.

Nice... Saves just turning it off I supose...

 

[Cappen Boidseye]

Interesting about diesels working better under load. My 27 ft yacht has an 18 hp Perkins 3 cylinder diesel. I tend to use it on fairly low throttle settings because it will give me an easy 5 knots without having to work hard, seems ok in a 27 foot boat, plus the throttle slips back from any high settings. The engine is basically a marinised small industrial engine. I don't have a tacho so I can't give any more info on engine speeds, but I don't think I cruise at much more than half revs, should I work it harder to prevent any glazing happening?

 

[[2574]]

Surely the answer is rig your boat not to need charging via running the engine? With this objective I've:

1) added a 200w array of photovoltaic panels; in "normal" English summer weather the array can keep up with our domestic power requirement (incl fridge on 24/7).

2) fitted a 120A alternator so if we were in constant no sun conditions (and therefore had no choice other than to engine charge) I apply the <80% rule; only ever run the engine when battery remaining capacity is under 80% and thereby keep the alternator operating in bulk phase. That way it's possible to bang in 80A or so in one hour to minimise the need for engine charging and maximise charging efficiency.

3) increased battery capacity to 600AH to allow multiple days consumption without needing to recharge

Engine charging with a standard automotive alternator/regulator setup is so hideously inneficient as to make it a nonsense on cost, mechanical and environmental grounds. An 120A alternator needs about 3hp to drive it IIRC so a standard automotive setup (50A alternator without a 3 stage regulator) putting in probably <15A requires probably about one third of one horsepower. So even with say a 25hp diesel it's using less than 2% of the engine's capacity. The energy inneficiency rating is off the scale, go solar!

rob

 

[vyv_cox]

Interesting about diesels working better under load. My 27 ft yacht has an 18 hp Perkins 3 cylinder diesel. I tend to use it on fairly low throttle settings because it will give me an easy 5 knots without having to work hard, seems ok in a 27 foot boat, plus the throttle slips back from any high settings. The engine is basically a marinised small industrial engine. I don't have a tacho so I can't give any more info on engine speeds, but I don't think I cruise at much more than half revs, should I work it harder to prevent any glazing happening?

Glazing is highly unlikely in any engine that is working, almost no matter how lightly, so long as it gets up to a temperature where the thermostat is operating. However, Yanmar suggest in their workshop manual that engines running on part throttle should be run flat out for five minutes every two hours. This is intended to oxidise carbon deposits inside the combustion chamber. Running flat out for half an hour or so is a well-known maintenance trick used by many boatyards.

 

[Loggo]

Following my recent experience on the Thames (often at Wallingford) the answer is plain. If you run your engine/ generator for 3 hours or so in the evening all you need to do is sit in the saloon watching television and your are hardly disturbed at all.

As for those sitting outside with a quiet (!) glass of wine wanting to enjoy the evening ? Should have brought the telly !

 

[Searush]

Following my recent experience on the Thames (often at Wallingford) the answer is plain. If you run your engine/ generator for 3 hours or so in the evening all you need to do is sit in the saloon watching television and your are hardly disturbed at all.

As for those sitting outside with a quiet (!) glass of wine wanting to enjoy the evening ? Should have brought the telly !

Jeez, give me strength!
If I WANTED to watch telly I wouldn't be at the boat! One of the main reasons I go to the boat is to get away from Telly & to be outdoors, enjoying an old-fashioned & simple way of life. You might as well sit in a shed at the end of the garden.

Edit: FFS, just get rid of most of the non-essential electrical junk on your boat - it mostly isn't cost effective, it certainly isn't needed and the sailing excperience is generally better without it!

 

[alan_d]

Jeez, give me strength!
If I WANTED to watch telly I wouldn't be at the boat! One of the main reasons I go to the boat is to get away from Telly & to be outdoors, enjoying an old-fashioned & simple way of life. You might as well sit in a shed at the end of the garden.
]

Don't you think Loggo's post might have been a teensy bit tongue-in-cheek?

 

[Searush]

Don't you think Loggo's post might have been a teensy bit tongue-in-cheek?

SSSsshhh, don't tell everybody!

 

[hannahman]

I run the engine in my boat from time to time, on the berth. It's raw water cooled, so I like to flush it through with fresh water, when I know that I'm not likely to be using it for a period.
My boat is berthed in a rather 'sleepy' marina, in close proximity to houses, so I tend to choose windy days, when the rather loud 'pop pop' exhaust note from her old Petter engine is drowned out by the noise of the wind and clanking halyards etc!