FullCircle
Well-Known Member
True, my Jeanneau is wired to only work the windlass with the engine running, but I have fitted an emergency switch so I can parallel the house bank to operate the windlass if the engine cannot be started for any reason.
Two alternators vs one big fat one?
- Thread starter Saguday
- Start date
Saguday
Well-Known Member
Ahem. This thread concerns alternators, not windlasses and bow thrusters.
Besides which a) we run the engine when using the windlass and b) we have no bow thrusters.
Can I also state that I have no "obsession" about running huge alternators I'm simply looking at the most economical and reliable configuration to provide an engine-driven charging capacity roughly equivalent to what the boat had when it was new. We do have some largish continual loads (refrigeration predominantly which the SP's support during daylight) but kids on board with laptops and all the other modern gubbins do take their toll.
I will conduct some measurements with the battery monitor when I have time, after we eventually get to our intended winter destination.
Besides which a) we run the engine when using the windlass and b) we have no bow thrusters.
Can I also state that I have no "obsession" about running huge alternators I'm simply looking at the most economical and reliable configuration to provide an engine-driven charging capacity roughly equivalent to what the boat had when it was new. We do have some largish continual loads (refrigeration predominantly which the SP's support during daylight) but kids on board with laptops and all the other modern gubbins do take their toll.
I will conduct some measurements with the battery monitor when I have time, after we eventually get to our intended winter destination.
temptress
Well-Known Member
I have tries all sorts of combinations over the years and have settled on one Big balmar at 180amps wit twin belts AND one Hitachi 60 amp with a smart controller.
The Balamr is connected to the the domestic bank) 750AH) and the Hitachi is connected to the engine battery 120 ah. Both independent of each other but the banks can be combined if needed. This works for us very well.
Getting the brackets and wiring right took some effort but as we live on board it has been worth the effort.
And I carry a spare Hitachi alternator and a spare smart controller just on case. As well as wind and solar....
The Balamr is connected to the the domestic bank) 750AH) and the Hitachi is connected to the engine battery 120 ah. Both independent of each other but the banks can be combined if needed. This works for us very well.
Getting the brackets and wiring right took some effort but as we live on board it has been worth the effort.
And I carry a spare Hitachi alternator and a spare smart controller just on case. As well as wind and solar....
pvb
Well-Known Member
What sort of current does the 750Ah bank accept?
temptress
Well-Known Member
I see this as a backup option. We are often in remote places several weeks away from any sort of engine help so it. Makes sense to me to have 2 alternators
RobbieW
Well-Known Member
Not an easy question to answer, knowing something about your usage and how the Balmar (& presumably its replacement) was/is regulated would add a bit to the discussion.
From my experience I use +- 100A daily, thats in the Med with a fridge on 24/7 + 2 x laptops being the major loads. I have a nominal 720ah AGM house bank charged primarily by solar (200w) and alternator. After a couple of days I will have a deficit as the solar doesnt keep up with demand, the size of the deficit is variable and I'll run the engine to make up some of that deficit when my Link 2000 tells me its got to c. - 150amps. The alternator is capable of 160A at 12v, its a Balmar regulated by a Balmar 614, throttled to about 130A using the belt load manager function of the regulator. I normally see c. 105-110A delivered initially which settles after a few minutes to around 90A during the bulk phase and slowly reduces until I've had enough of the engine running - after about an hour it'll be c. 20-30A.
I'm using a deliberately overspecced alternator to try and extend its life, combining that with the regulator functions to maximise the charge rate and minimise alternator wear. I'm not sure if the cost of the alternator justifies itself when compared with (much) cheaper off the shelf components but I dont know where the cost crossover is yet. I've chosen my components to give me as much control of the charge cycle as I can get which was important to me in the design of my charging system. One thing I've learned is that Balmar regulators operate on the -ve field line whereas most European alternators are configured to be regulated on the +ve field line; is that important ? I'm sure it is where the alternator has a built in controller.
I think my priority was charge time over economy which led to my choices. The Sterling AtoB charger was one I considered in combination with a cheaper, but still high spec, alternator. I think the ability to control the charge cycle, basically the switching points between bulk/absorption/float, was the determining factor in choosing the Balmar regulator.
The other comment I'd make is that I find myself occasionally doing long, 24hr +, motoring trips. I wanted a system that would keep the voltage at float levels once the batteries were fully charged, my system does that.
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temptress
Well-Known Member
Depending on the state of discharge usually 60 to 70 amps for 50 minutes or so then tails off to 25 to 30 amps..... If the batteries have had a hammering and we have not had any help from the Solar or Wind then I've seen 120 amps for minutes or so before flopping to say 60ish for an hour or so.
The setup works well for us. We live on board and often go 8 or 9 months between shore power availability. Usually at anchor where the wind genny is useless most of the time.
Batteries are large wet cell traction type. I have to top them up occasionally.
When the sun is shining we occasionally have too much power available, the batteries get to full charge. When this happens we turn the fridge thermostat down and use the watetmaker so we can indulge in better showers. Doesn't happen often mind you
geem
Well-Known Member
As as already been said here, check what your existing alternator is inputting to your battery bank.if it doesnt go over 80 amps then a bigger alternator is a waste of time
lw395
Well-Known Member
A lot of people pontificating about what's right for other people though.
Some people do use heavy loads for significant periods and find it better to have a powerful alternator setup.
It's not the right way for everyone but suits some.
Personally I like the 'reduce power use' or 'fit generator' schools of thought, depending on how the boat is to be used.
pvb
Well-Known Member
That rather confirms my suspicion that your twin-belt 180A alternator is perhaps rather over-specified!
geem
Well-Known Member
Its interesting how different our setup is as we too are liveaboards. We have 800 amp hr domestic battery bank at 12v ( we are 24v but will convert everything to 12v for simplicity) and 220 amp hr for the engine. The engine alternator is 120amp and only charges domestic bank(but can be switched to engine if necesary). The engine and domestic banks are charged by our Duogen and 460w of solar via twin battery regulators. We also have a 4kVA genset that is mainly used to run the watemaker but we can also run the watermaker off the 3kw inverter as a backup. This needs the engine running to reduce the amps taken from the battery bank as the alternator wont keep up with the 1.5kw 220v watermaker motor. We don't need to run the watermaker for long periods of time as we make 2.2litres per minute with our setup. The generator also has a 60 amp battery charger which we occationally run when making water if we are not using thr immersion heater to make us a tank of hot water whilst making water.
My thoughts on charging is not to have all you eggs in one basket. Off the beaten track, access to spares is often difficult. If one of our systems goes down we can cope pretty easily with the remaining systems with minimal impact on day to day life.
The engine alternator is just one system and at 120amps for an 800 amp hr bank we seem to spend a suprising amount of the time charging at just 40 amps with this dropping off to 30 amps within a short time. An oversized alternator is very expensive with little to gain unless you have a massive battery bank IMHO
Dockhead
Well-Known Member
800 squids??
What makes you think you need to replace it? There's almost nothing which can go wrong with one of those, which can't be repaired. I melted the stator on my Leece Neville (stupid operator error), and had the whole unit rebuilt with a new stator for I think 140 quid. Now good as new.
Saguday
Well-Known Member
It's corroded and completely seized, alternator shop wouldn't repair it (I still have it on the off chance I can get it repaired at some point).
Do a google search - best price I found was £780 inc VAT to replace it (7-10 days delivery) and most places were much more for a current model (120A) Balmar to fit a Yanmar.
Do a google search - best price I found was £780 inc VAT to replace it (7-10 days delivery) and most places were much more for a current model (120A) Balmar to fit a Yanmar.
ShinyShoe
Well-Known Member
So forgive my niavity...
Why not just put on a Renault Megane 1.5dCi Alternator...? Rated to 110Amps at 12V
I'm guessing brackets might need modified etc... but you'd get a scrap one for <£100
Why not just put on a Renault Megane 1.5dCi Alternator...? Rated to 110Amps at 12V
I'm guessing brackets might need modified etc... but you'd get a scrap one for <£100
Saguday
Well-Known Member
Mounting bracketry and time to repair was a significant issue at the time - for a number of complicated and inter-related reasons the problem was found late in the day and we had to sort something out quickly. As it happened we lost half of our two week summer cruise getting the engine back in service.
FullCircle
Well-Known Member
Most marine alternators (exccepting the likes of Balmar) are car alternators of sorts. The problem is they are too powerful for many of the engines we have in our smaller boats, and above 80a, you will need to change away from the single pulley V belt we all know and love, for the multi v wide belt arrangement on your car. The load on your poor little 1GM Yanmar would severely restrict the performance of the engine to actually propel the boat. This also would invlolve a lot of expense, as the likes of Yanmar, Beta, Nanni etc cunningly seem to have non standard pulleys. In other words, it a bit of a faff.
My Yanmar 3YM30 comes with a 60a as standard, but there always was an option for an 80a - a bit of investigation showed this is a Hitachi LR03C whih is readily avalable at ....£70 as opposed to Yanmar wanting £360.
RichardS
N/A
+1
Just for information, if anyone is searching for this 80A alternator online the full name is LR180-03C.
Richard
lw395
Well-Known Member
I put a Mondeo alternator on a Yanmar 3GM.
It needed some spacers, washers etc, and a tiny biy of surgery to the yanmar bracket.
cost £20, plus a few shillings for washers....
And a pulley which IIRC came from a Vauxhall Viva.
I had my own soft start circuit to reduce belt wear at low rpm after starting.
But belt wear was still on the high side.
Not charging a particularly big bank, about 250Ah, but also running a fridge.
While 'boost' charging at 1200rpm (engine) I could get nearly 100A from the alternator, but after a bit of experimentation I throttled it all back a bit.
This was some years ago, I would take a different approach now.
but we have similar problems in other fields, like powering a big radio transmitter from a vehicle.
A second, 24 or 28 volt alternator is perhaps favourite....
Ludd
Well-Known Member
A few years ago , a skippred charter boat(Jeanneau,I think) was in Tobermory on a Friday of a Bank Holiday weekend. His main alternator had bearing failure, threw the belt and as a result engine couldn't be used (no cooling). The second alternator had totally different fittings, so couldn't swap it over. Bloody stupid setup,I thought!
My solution to get him moving was to use the spindle from the alternator to mount a snatch block ,through which the drive belt could be run to drive the coolant pumps, fresh and seawater.
Lasted him a week till he was able to get a proper job done. The owner questioned my bill of £25 for the snatch block (one of a pair) so I slammed the phone down on him. OOPS! HE THOUGHT IT WASN'T ENOUGH AND SENT ME A CHEQUE FOR £100!
Moral: if you fit a second alternator, make sure they are interchangeable.
My solution to get him moving was to use the spindle from the alternator to mount a snatch block ,through which the drive belt could be run to drive the coolant pumps, fresh and seawater.
Lasted him a week till he was able to get a proper job done. The owner questioned my bill of £25 for the snatch block (one of a pair) so I slammed the phone down on him. OOPS! HE THOUGHT IT WASN'T ENOUGH AND SENT ME A CHEQUE FOR £100!
Moral: if you fit a second alternator, make sure they are interchangeable.
FullCircle
Well-Known Member
A valid point, and mine is the same, except it is a 60a.