Alternators and sense wires

[dmr]

My own view, like you, is that alternators are probably best regarded semi-consumable items, so I would not worry too much about preserving a warranty and just make the modification needed for an external controller.

A lot of people obviously do not see it this way as this is the main reason for the existence of the Sterling A to B device.

 

I suppose some of the new big alternators are getting a bit expensive, especially if purchased from Beta/Barrus/Vetus etc, so I can sort of understand owners worrying about them, and those who don't have practical skills will also be paying somebody to do the fitting.

 

............Dave.

[by'eck]

 

I would think that fitting either a controller (with a wire fixed to a brush) or an "A to B" could void any warranty as you have changed the operating characteristic of the alternator. Controllers can make an alternator work quite a bit harder than intended so if the design is thermally marginal they could do damage. I have heard that Beta specify No controllers on their bigger alternators.

The advantage of the A to B is that if YOU remove a failed alternator and return it the supplier will not know that it had a controller fitted, though they will probably guess.

The A to B looks like a lot of power electronics just to avoid what is usually a very quick alternator modification.

 

.................Dave

 

With the external DAR solution yes since you are opening it up, but with the A to B device surely no. It uses its own regulator exclusively. It works no harder than if stand-alone charging a large depleted battery bank (relative to alternator size) and employs alternator temp sensing - see post #41. If its a rubbish under spec'd device, the cooling is marginal and/or the fan speed to slow (running engine at just above idle) that's another matter and likely to cause issues with or without device.

 

The A to B device has been referred to by some as a battery boiler, although I'm sure its saved more than its destroyed - I haven't seen so many comments to the effect its an alternator fryer.

[dmr]

 

With the external DAR solution yes since you are opening it up, but with the A to B device surely no. It uses its own regulator exclusively. It works no harder than if stand-alone charging a large depleted battery bank (relative to alternator size) and employs alternator temp sensing - see post #41. If its a rubbish under spec'd device, the cooling is marginal and/or the fan speed to slow (running engine at just above idle) that's another matter and likely to cause issues with or without device.

 

The A to B device has been referred to by some as a battery boiler, although I'm sure its saved more than its destroyed - I haven't seen so many comments to the effect its an alternator fryer.

 

A while ago, on this forum, I said that fitting an alternator controller would not make an alternator work harder (and that Sterlings suggestion to fit thicker cables was only marketing BS). My recent experiences have suggested that I was wrong here. In the summer I fitted a Beta style Iskra 100 amp alternator. as my old Prestolite eventually died.

With the battery bank at 50% charge I noted that the internal regulator started to reduce the alternator current after just a few minutes and the alternator ran moderately hot. With the Adverc connected the alternator remained at full output for much much longer and the alternator got very hot indeed. I suspect I had hit on almost worse case conditions as I have a bit of resistance in the battery isolator and am not running the alternator very fast, but the Adverc did make a dramatic difference to alternator temperature.

Interestingly my current solution to this is to run the alternator even slower by fitting a slightly bigger pulley.

 

I have heard that Beta say do NOT fit external controllers to their alternators.

I suspect the Sterling over-temperature shutdown would save an alternator from over heating but it would be quite difficult to locate the sensor to work correctly. I believe modern alternators are happy to run much hotter than 120 degrees so the Sterling may well shut down much too enthusiastically.

 

..............Dave

[bottle]

Beta did in fact fit a 'battery boiler' at one time but had so much trouble with alternators that they stopped.

 

Now as to why they had problems I have no idea, perhaps under spec. alternators or badly designed 'boiler'.

 

Probably the best solution is an alternator designed and spec'd. for the job it is expected to do.

[Loafer]

Beta did in fact fit a 'battery boiler' at one time but had so much trouble with alternators that they stopped.

 

Now as to why they had problems I have no idea, perhaps under spec. alternators or badly designed 'boiler'.

 

Probably the best solution is an alternator designed and spec'd. for the job it is expected to do.

 

I don't know of an alternator that is designed and spec'd to charge wet lead acid batteries correctly!

 

Anyway, a most informative bunch of responses, thank you. I'm going to wire the AB charger back in next week and see how it goes. These Trojans really need 14.8V, or so `I believe, and they won't be getting that off my alternators without the AB doodad.