dual altinators

[axeman]

has or is any one running a dual altinator set up on there vans, i have the option to run 2 now, i was thinking of useing a 100amp one for the main starter battery and the second for the second battery that i have for a couple of things inside of the cab, propex, interia lights, ect. and ditching the relay based charging system that i curently have, as i understand it the atinators only generate power as there is a demand for it, so i would imagen that there would not be too much draw on eather of them at any one time?

any one got any thoughts

neil

[kevtherev]

I would think that's just overkill in a big way

I have a 45A Alternator it provides power for three batteries.
a 200 watt head unit and amp, propex, DVD, TV, X box, lights, phones and hair straighteners.

It has never failed to charge the leisures and the starter batteries back up.

[Oldiebut goodie]

All you will do is sap valuable horses from the engine for no gain. Only worth it if you are going to run a 12v system alongside a 24v (or other) one.

[AdrianC]

any one got any thoughts

The only reason you need to uprate your alternator is if you're using the juice faster than you're putting it back in - or if you're flattening the leisure battery whilst camped and not running the van for long enough to recharge it.

Even a tiddly 25A alternator will fully charge ANY size battery - even <say> three mahooosive 100Ah ones - it'll just take a few hours to do it - 300Ah total, charged at 25A, will take 12hrs to charge.

[axeman]

thanks lads,

dont think that i will do it from what you have said, just there was a car being scraped at the nakkers yard and they have a mount and a 100amp altinator on it, would be an easy add on to my engine.

neil

[Red Westie]

Having seperate alternators does have significant advantages when charging two batteries on their own circuit.
There is a well known phenomonen that occurs with split charge systems where, because of the way the alternator senses and regulates charge, the second, often larger capacity battery, never reaches full charge state. In fact there are very expensive devices (the proper name escapes me) that are available to ellimate this issue.
You have a valid point, alternators do 'resist to turn' depending on how much they are charging but with nearly full state charge they have much reduced resistance. Two alternators would indeed take more turning but as the load is shared it wouldn't be 'twice' the load so wouldn't sap as much power out of the engine as you might think.
The reduced demand on each alternator would also extend bush and slip ring life.

Yes I know...trust me to contradict everyone.

Having said all of this, the wiring may be more complicated as you would need a second charge light installing so 'sensing' for the regulator comes from the alternator charging the second battery.

Interesting all the same but just how useful the setup would be is debatable but both sides of the aguement are worth hearing.

Martin

[kevtherev]

So convincing that you did it
and your engine has twin 'naters....

Of course not, because there's no need to fit two.
Therein lies the conclusion.

[ringo]

Just fit that sterling jobbie like Lloydy has got....

How much!

I have to say, unless you are life dependent on your electrics then i dont think there is any point - but then hobbies arent about there being a point are they!

I've seen the setup on a ex military van at vanfest - looked very smart. Theres not exactly loads of room for it though....

Ringo

[AdrianC]

Theres not exactly loads of room for it though...

Mmm. I found myself cursing the presence of the power steering pump t'other day. A second alternator in there would just have been taking the mick.

[Red Westie]

Hey......just sounding out both sides of the discussion.....and if it's free well that might persuade someone with too much time on their hands to give it a go.
Martin

[axeman]

the reason that i asked was becouse it is in a syncro and the altinator is in a vunurable location, for off road use. and was always some thing that need ed to be addressed. at present there are 2 bets for it that go via the crank, water pump altinator.



i bought a bracket from a later car as the altinator was located on the other side of the engine and more inportantly much higher up. which is what i wanted, there was just the option of running 2, the only dow side was that i now only have one belt instead of the 2. even with this set up a could add a power stering pump and an a/c compresser. food for thought?



neil

[lloydy]

Just fit that sterling jobbie like Lloydy has got....

How much!

Who would fit such a pricey thing
The usual ebay bargain after weeks of looking, one on 'buy it now' turned up at a 1/3 of the price. Couldn't justify shop price.
Neil, have you not considered getting a mahoosive leisure battery, and a mains 4 stage charger, then just plug it in before a weekend away, so it gets a full charge?

[jed the spread]

The green hightop 16" army Syncros had duel alternators I think I read somewhere in the past. Might have been the German Army, fitted on DJ engines.

jed