Alternator regulator

[Martinb2347]

Morning all

 

I was wondering if anyone had fitted a alternator regulator to a lister SR3 and whether this had the desired effect to getting a better charge.

 

[Tracy D'arth]

There is no substitute for revs, a bigger camshaft pulley is the best way, then an alternator controller, like Sterling or Adverc.

[Martinb2347]

6 minutes ago, Tracy D'arth said:

There is no substitute for revs, a bigger camshaft pulley is the best way, then an alternator controller, like Sterling or Adverc.

Thanks tracy, we did look at the pulley set up and sadly the large pulley would involve alot of work and hull changes due to the position of the engine.  Trying to weight up cost and benefit.

[Tony Brooks]

Tracy is correct but a fuller answer.

 

The lack of revs presents itself as less amps and during the earlier stages of charging less volts that would be available on a system that is running at higher alternator revs. This means that the time it takes for your system to charge the batteries to the point at which the voltage will rise high enough for the voltage regulator to work will be much longer. If you  never or rarely run long enough to get to the point at at which regulation takes place then adding an additional regulator set to an even higher voltage (that is all most alternator controllers are) will achieve absolutely nothing. However if you do run for long enough then when the controller shorts out the inbuilt regulator you will get a higher charging current.

 

So all that comes down to how long to you normally run your engine for and what time elapses between the regulator working and engine shutdown. On a typical reasonably modern alternator the regulated voltage is likely to be in excess of about 14.2 volts but for older ones it could be between 13.8 and 14.2 volts. You will know what it is on your system if you keep running the engine until the voltage stops gradually rising and stabilises for a hour or so.

 

Then there is the Sterling A to B device but all it does is play about with the Charging volts = Watts divided by Amps and as the Watts is fixed by your low pulley ratio it will again make very little if any difference.

 

If you can get a 14.5 or 14.6 volt regulator for your alternator or even a 14.7 one if you have open cell batteries it will be about the best you can do and probably a lot cheaper than a controller.

[Tracy D'arth]

Or a smaller alternator pulley?

[Tony Brooks]

1 minute ago, Tracy D'arth said:

Or a smaller alternator pulley?

Agreed but then a notched (toothed) belt will be important to fit around the smaller diameter.

[Man 'o Kent]

15 minutes ago, Tony Brooks said:

Agreed but then a notched (toothed) belt will be important to fit around the smaller diameter.

Good advice, there is only so far that a "Vee" belt can be deformed around a small pulley before the stresses created lead to rapid wear and eventually failure.

A "toothed" belt has the advantage of providing a positive drive but it should be noted that that a large difference in pully diameters can lead to too few belt "teeth" being engaged again leading to localized stresses and failure which is why many modern car engines have jockey wheels to increase  the tooth count with the pullies.

Remember that including mechanical and electrical losses plus hungry batteries that belt may be trying to transmit two or three horsepower.