Adding a 2nd alternator

[WotEver]

Hi,

 

We have a Vetus M310 which currently has only a single alternator charging via a split charge relay. I've tried Googling with no success to see if there is a simple method of adding a 2nd alternator.

 

Anyone know?

 

Or is it a case of fabricating my own bracketry and trying to find a suitable length fan belt? I don't have any room for a 2nd pulley on the crankshaft, so if we did this the new alternator would have to be fed along with the existing alternator and water pump. I know that the wrap angle is important, which is the main reason why I'd prefer to go the route of a professionally designed solution if possible.

 

Or maybe I should simply swap the existing alternator for the largest single that can fit. Does that sound like a better solution?

 

TIA,

Tony

[Arnot]

Or maybe I should simply swap the existing alternator for the largest single that can fit. Does that sound like a better solution?

Yes it does. Given that you have a narrow boat, virtually all of the output of the alternator will be used to recharge the domestic batteries so a large alternator connected directly to them with a split charge relay to divert what little is required to the engine battery will work just fine and be relatively simple.

 

Twin alternator setups tend to come as standard with marine engines to both increase output, allow full separation of domestic and starter systems and also allow some redundancy so if you are in the middle of an ocean and one alternator breaks, you have a get out of jail card. Of course when the towpath is only feet away, it's not so important.

 

Regards

 

Arnot

[WotEver]

Terrific, thanks Arnot

Edited August 21, 2009 by WotEver

[Gibbo]

Yes it does. Given that you have a narrow boat, virtually all of the output of the alternator will be used to recharge the domestic batteries so a large alternator connected directly to them with a split charge relay to divert what little is required to the engine battery will work just fine and be relatively simple.

 

Twin alternator setups tend to come as standard with marine engines to both increase output, allow full separation of domestic and starter systems and also allow some redundancy so if you are in the middle of an ocean and one alternator breaks, you have a get out of jail card. Of course when the towpath is only feet away, it's not so important.

 

Seconded. Absolutely. No question.

 

Gibbo

[dor]

Check carefully what will fit. If I remember rightly, there is not a lot of space to fit a physically larger alternator due to the manifold.

[churchward]

Yes it does. Given that you have a narrow boat, virtually all of the output of the alternator will be used to recharge the domestic batteries so a large alternator connected directly to them with a split charge relay to divert what little is required to the engine battery will work just fine and be relatively simple.

 

Twin alternator setups tend to come as standard with marine engines to both increase output, allow full separation of domestic and starter systems and also allow some redundancy so if you are in the middle of an ocean and one alternator breaks, you have a get out of jail card. Of course when the towpath is only feet away, it's not so important.

 

Regards

 

Arnot

I agree and given that the alternator you will be swapping out still works you can keep that on board for emergencies and a get you home fix in case of alternator failure.

[WotEver]

I agree and given that the alternator you will be swapping out still works you can keep that on board for emergencies and a get you home fix in case of alternator failure.

 

Good point

 

Check carefully what will fit. If I remember rightly, there is not a lot of space to fit a physically larger alternator due to the manifold.

 

Yes indeed - it won't be able to be hugely bigger physically although I do have the space for it to pivot upwards somewhat if I could find a suitable fan belt.

 

T

[churchward]

Yes indeed - it won't be able to be hugely bigger physically although I do have the space for it to pivot upwards somewhat if I could find a suitable fan belt.

T

It shouldn't be to difficult to get a longer belt if you go to one of the main suppliers on line of industrial belts. They will say a variety in quite small increments of length. For instance if your belt is 1000mm long as std it should be possible to get one 1010mm to 1050mm in length.

 

For example have a look at this website

 

http://www.bearingboys.co.uk/beltsearch.cg...amp;section=SPZ

[WotEver]

For example have a look at this website

 

What a great site - another one for the bookmarks.

 

Ta

[Boatgypsy]

Try this one too!

 

http://www.medwaypt.co.uk

[WotEver]

Try this one too!

 

http://www.medwaypt.co.uk

 

Cool, thanks

[andystobart]

How did you get on with the alternator action? I'm looking at the same scenario with my M3.10 before it goes back in.

 

Did you find a twin set-up or go for a large single one?

 

Many thanks

 

Andy

[WotEver]

How did you get on with the alternator action? I'm looking at the same scenario with my M3.10 before it goes back in.

 

Did you find a twin set-up or go for a large single one?

 

Many thanks

 

Andy

Hi Andy,

 

Like so many things in my life it's gone onto the back boiler. We don't actually use a lot of electric (no inverter, very occasional short blasts of TV off 12V, new efficient fridge) so it's something that I may get around to one day.

 

I even have one of those A127 tractor regulators with the extra wire just in case I need one one day - I'm that kind of hoarder

 

If you do it then please report back

 

Cheers,

Tony

 

edit to say that when/if I do get around to it I'll be doing it with a larger replacement as suggested by the experts. I shan't faff about with a 2nd one.

Edited May 19, 2010 by WotEver

[Guest]

If the Vetus 310 is like my Vetus 415, then the v belt is rather narrow. Ours has a 90 Amp Alt and gets through a belt each season. I think this may be your limiting factor.

[WotEver]

If the Vetus 310 is like my Vetus 415, then the v belt is rather narrow. Ours has a 90 Amp Alt and gets through a belt each season. I think this may be your limiting factor.

I suspect you'd be right.