Power generation

[DaveGood]

The alternator to battery Bank matching was explained to me in the following way.

 

If you bought an ordinary family car then strapped on two tons of armourplating. You either replace the engine with something that can cope with hauling around the extra wieght, or expect to have to continually thrash your engine, shortening it's working lifetime from years to months.

 

Can,say, a 50 amp alternator, recharge a 500 Ah Battery Bank? Sure, does anyone know a reputable Manufacturer that either sells or reccomends such a setup? No.

 

Everyone I've looked at state that if you add more Battery Ah then the alternators supplied can handle ( about three to four to one) then the warranties on the alternators are void.

 

Of course adding other amp inputs such a solar panels or generators while keeping the original small alternator achieves the same thing as swapping out a small alternator for a bigger one. which is what you've done Julynian.

 

DaveGood

Edited January 20, 2014 by DaveGood

[bottle]

If you increase your battery bank (Amp.Hrs) run with the alternator you have, if it goes pop buy a new/recondition one but think about fitting a better/larger one.

[Biggles]

In my considerable research for larger alternators etc, I was of the impression that an Alternator was rated at continuous as there is no other data to support different duty cycles.

 

Of course seldom will an alt. need to output maximum for long continuous periods if its simply charging batteries.

 

On the whole I would say an Alt is one of the most reliable bits of kit on a boat. And when its broke the fix is always a simple one all be it an unwelcome expense at any time

The alternator to battery Bank matching was explained to me in the following way.

If you bought an ordinary family car then strapped on two tons of armourplating. You either replace the engine with something that can cope with hauling around the extra wieght, or expect to have to continually thrash your engine, shortening it's working lifetime from years to months.

Can,say, a 50 amp alternator, recharge a 500 Ah Battery Bank? Sure, does anyone know a reputable Manufacturer that either sells or reccomends such a setup? No.

Everyone I've looked at state that if you add more Battery Ah then the alternators supplied can handle ( about three to four to one) then the warranties on the alternators are void.

Of course adding other amp inputs such a solar panels or generators while keeping the original small alternator achieves the same thing as swapping out a small alternator for a bigger one. which is what you've done Julynian.

DaveGood

 

Not sure thats a good analogy. The car will always have 2 tons extra strapped to it. The load on an alt is a quickly reducing one. Maybe think of it as a 2 ton load losing 100kg every minute might give a better view.

[nb Innisfree]

A vehicle alt runs cooler due to airflow, bulk charge usually lasts a very short time after start up, the only time it's under full load for any length of time is when all the electrics are on.

[jenevers]

Does anyone ever run a washing machine via their engine alternator/batteries/inverter, whilst on the move?

 

I tried it once for a few minutes. The engine slowed noticeably (obviously) but my main concern was how hot the 180 Amp alternator got!

 

I decided to wait until I moored up and plug into the mains rather than risk wrecking the alternator.

[Robbo]

2000watt (guess of how much a washing machine will use when heating water) is around 170amp so guessing your alternator running flat out. It shouldn't be for a long period (until the water heated up) unless you have a large battery bank that needed charging as well.

 

None marine alternators don't like been ran at 100% for good periods, but check the cooling fan of the alternator is in the right way or if can be improved - I'll find a link regarding.

[Robbo]

None marine alternators don't like been ran at 100% for good periods, but check the cooling fan of the alternator is in the right way or if can be improved - I'll find a link regarding.

 

I'll extend my answer on this as now not typing via phone!

 

Alternators can be put on so they can rotate in either direction, they generator electricity just fine either way. However, the alternator fan may not be bi-directional, so you need to check and make sure it's sucking the air through the alternator. - http://www.cdxetextbook.com/electrical/chargStartLight/altCons/alternatorcoolfan.html

[Phil Ambrose]

 

I'll extend my answer on this as now not typing via phone!

 

Alternators can be put on so they can rotate in either direction, they generator electricity just fine either way. However, the alternator fan may not be bi-directional, so you need to check and make sure it's sucking the air through the alternator. - http://www.cdxetextbook.com/electrical/chargStartLight/altCons/alternatorcoolfan.html

Just to help things along on mine I put a large computer fan on the strap bolt to hopefully cool it a bit oor at least dissapate some heat.

Phil

[Robbo]

Just to help things along on mine I put a large computer fan on the strap bolt to hopefully cool it a bit oor at least dissapate some heat.

Phil

 

You could use a bilge blower, ducted to blow cooler air at the back of the alternator. You may even be able to get a cover for it - Linky

[cereal tiller]

 

You could use a bilge blower, ducted to blow cooler air at the back of the alternator. You may even be able to get a cover for it - Linky

I have 3 alternators on main engine,the 2 that charge the domestic bank have centrifugal bilge blowers behind them.

 

They draw 36 watts each,not much in the scheme of things

 

Testing after installation revealed a 30 degree c.drop in running temperature at full load,.....Cool!

 

 

 

CT

[Robbo]

I have 3 alternators on main engine,the 2 that charge the domestic bank have centrifugal bilge blowers behind them.

 

They draw 36 watts each,not much in the scheme of things

 

Testing after installation revealed a 30 degree c.drop in running temperature at full load,.....Cool!

 

3! Now isn't that a bit greedy - Do you have photos of your setup?

[cereal tiller]

 

3! Now isn't that a bit greedy - Do you have photos of your setup?

Number 1 alt. is the original 35 amp type Lucas.

 

No.s 2 and 3 are mounted one each side of the engine and driven by a 10 inch double pulley .

 

ALT 2 is a 70 amp

 

Alt 3 is a 90 amp

 

at a slightly raised idle the total output is 140 amps

 

Pictures of my set up?i only show those to suitable femmes!

 

No 10 inch references.please

 

CT

[jenevers]

 

I'll extend my answer on this as now not typing via phone!

 

Alternators can be put on so they can rotate in either direction, they generator electricity just fine either way. However, the alternator fan may not be bi-directional, so you need to check and make sure it's sucking the air through the alternator. - http://www.cdxetextbook.com/electrical/chargStartLight/altCons/alternatorcoolfan.html

That's interesting. Are ALL alternator fans designed to suck air through the back of the alternator. I always assumed they blew air through from the front? I'll have to check mine next time.

[MyLady]

That's interesting. Are ALL alternator fans designed to suck air through the back of the alternator. I always assumed they blew air through from the front? I'll have to check mine next time.

 

In my limited experience (cars) all the alternators/dynamos I have come across had a centrifugal fan, so blew air away from them, sucking air from behind...

 

Roger

[jenevers]

 

In my limited experience (cars) all the alternators/dynamos I have come across had a centrifugal fan, so blew air away from them, sucking air from behind...

 

Roger

Checked mine and ....yes it sucks air in from the back and blows out at the front. You never stop learning. I always thought they blew air in from the front.

[by'eck]

Checked mine and ....yes it sucks air in from the back and blows out at the front. You never stop learning. I always thought they blew air in from the front.

 

Guess that way it cools the diodes first.

[Lady Heidi]

Question - how do you get solars to heat your water ?? I'm a noob and I'm struggling with my batteries at the moment ... 3 x110 leisures 230 watt solars, 1000 watt inverter just for charging laptop - everything else is 12v (ipad, iPhone etc) I've got LED lights but I do have a 12v shoreline fridge freezer ... Just bought a genny too 2.2 KW pure sine wave one which I use for the immersion, Hoover etc if I decide not to run my engine x x

[Lady Heidi]

Question - how do you get solars to heat your water ?? I'm a noob and I'm struggling with my batteries at the moment ... 3 x110 leisures 230 watt solars, 1000 watt inverter just for charging laptop - everything else is 12v (ipad, iPhone etc) I've got LED lights but I do have a 12v shoreline fridge freezer ... Just bought a genny too 2.2 KW pure sine wave one which I use for the immersion, Hoover etc if I decide not to run my engine x x

[peterboat]

Hi,

The simple answer is you cant unless you have a large solar array and large battery bank. I have both and in the summer months can turn my immersion on and still have charged batteries at the end of the day plus a full tank of hot water.

You can buy a hot water solar panel and go down that route but they are quite large so may not be practical.

If your engine heats water like mine then you charge you batteries and heat water.

When you run the genny do you have a battery charger on as well which will help with keeping your batteries charged.

I think you are going to have to do a power audit first though just to check that you are not using more power than you are making.

 

Good luck

 

Peter

[Phil Ambrose]

I think Peter is right, the fact you are. Struggling with your batteries at the moment would indicate you are using more than you can produce and a power audit will probably prove this.

You need to either use less or produce more, the third option is to be able to store more ie more batteries.

Phil

[Lady Heidi]

Ok thanks guys x x

[Alan de Enfield]

I think Peter is right, the fact you are. Struggling with your batteries at the moment would indicate you are using more than you can produce and a power audit will probably prove this.

You need to either use less or produce more, the third option is to be able to store more ie more batteries.

Phil

 

If you increase your storage capacity you will still need to produce more - not only to fill the 'old' capacity but to fill the 'additional' capacity as well

[Paul's Nulife4-2]

I still think there could be some misunderstanding from maybe the newer members to their life afloat regarding making the connection in replacing used power.

What I mean is ,,Running your Engine, With say a 90a Alternator running for 1hr, would probably NOT put back onto your Battery, The 90a @ 12v (approx 1000watts @ 230v 'in round figures') that has been used say via an Inverter.

Depending on RPM, Battery SOC ect it might take 2 or 3 Hrs for it to be replaced, So if you have a 100% Charged Engine Battery, and Say a

90% Charged Domestic Battery,

it's probable that you would have to run your Eng for Say 15 minutes to top up your Engine Start Battery (Needed to start your Engine),

Then 2.5Hrs to Replace the 1000w used via the Invertor Say the Previous Night. And Then Additionaly another 30 minutes to top up you're Domestic Battery Bank from the to 100%.

So it 'Could ' Take well over 3 Engine Hours to Replace just 1000watts @ 230v used via an Inverter if the only source of Charging you have is a 90a Engine driven Alternator !.

Not the Hour some people may be thinking it would take. So now imagine using 2000w or more !. (Possibly 4 or 5 Hrs Eng Run.)

Maybe someone who can correct and present the above point better could elaborate.

 

Note to all the purists, above figures are rounded and approx, for easy understanding of a point trying to be made.

Edited May 6, 2014 by Paul's Nulife4-2

[Bettie Boo]

I still think there could be some misunderstanding from maybe the newer members to their life afloat regarding making the connection in replacing used power.

What I mean is ,,Running your Engine, With say a 90a Alternator running for 1hr, would probably NOT put back onto your Battery, The 90a @ 12v (approx 1000watts @ 230v 'in round figures') that has been used say via an Inverter.

Depending on RPM, Battery SOC ect it might take 2 or 3 Hrs for it to be replaced, So if you have a 100% Charged Engine Battery, and Say a

90% Charged Domestic Battery,

it's probable that you would have to run your Eng for Say 15 minutes to top up your Engine Start Battery (Needed to start your Engine),

Then 2.5Hrs to Replace the 1000w used via the Invertor Say the Previous Night. And Then Additionaly another 30 minutes to top up you're Domestic Battery Bank from the to 100%.

So it 'Could ' Take well over 3 Engine Hours to Replace just 1000watts @ 230v used via an Inverter if the only source of Charging you have is a 90a Engine driven Alternator !.

Not the Hour some people may be thinking it would take. So now imagine using 2000w or more !. (Possibly 4 or 5 Hrs Eng Run.)

Maybe someone who can correct and present the above point better could elaborate.

 

Note to all the purists, above figures are rounded and approx, for easy understanding of a point trying to be made.

I have no idea if you are correct or not Paul - but I do "kinda" get what your saying, which is going some as I'm one of the "newbie's" who is struggling with understanding how the whole power system works. So well done you

 

I'm currently at the point of asking Dave if it's ok for me to hoover, or use the bread maker or can I do a load of wash today (and do I need to turn the fridge off when I do)......my goal is to understand it enough that I won't have to ask and I can just get on with my tasks in the understanding I'm not going to blow up an alternator, damage the batteries or any of the other multitude of things I can damage due to an incompetent understanding of how the power system works.

[Paul's Nulife4-2]

It's a Dark art BB, but it does sort of become more a subconscious effort, you will just get to know, What power has been used, and therefore what is required to Replace it without even thinking about it in time !.