two alternator fails in one week

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Never made it on to the plane, Bloody pneumonia! Will try to get away next week if the antibiotics do their job. Bit uncomfortable out there for the past few weeks, they've had a claima (a dusty mist which holds the temperature in) and it was 43 degrees, good job I stayed home.:eek:

Pneumonia? Did your beer go down the wrong way?
 
Just recently fitted a new alternator to my V8. On the outside of the box there was warning that the battery must be fully charged before fitting the alternator. On the supplier's website it repeats this warning stating that failure of a new alternator mainly occurs due to not charging the vehicle battery.

Never heard that before. The alternator needs a bit of current to work but as long as the battery isn't shorted I cannot see what difference it would make. Still, if that's what they say, why take the risk?!
 
Never heard that before. The alternator needs a bit of current to work but as long as the battery isn't shorted I cannot see what difference it would make. Still, if that's what they say, why take the risk?!
I believe it has to do with current/voltage regulator being overloaded when attempting to quickly restore a poorly charged battery. Apparently alternators are not specifically designed as battery chargers and simply provide a steady current/voltage required by the vehicle's electrical load that normally includes just a trickle charge for the battery.
 
I believe it has to do with current/voltage regulator being overloaded when attempting to quickly restore a poorly charged battery. Apparently alternators are not specifically designed as battery chargers and simply provide a steady current/voltage required by the vehicle's electrical load that normally includes just a trickle charge for the battery.
Rhubarb. If an alternator is rated at 100 amps it can provide 100 amps and if the load is greater it should limit the current itself. That warning is simply a get out clause for them.
 
Rhubarb. If an alternator is rated at 100 amps it can provide 100 amps and if the load is greater it should limit the current itself. That warning is simply a get out clause for them.
This is an extract from near the beginning of QXComponents technical data booklet:

"Great your customer has bought an alternator They can fit it and forget it, not quite true, 85% of all alternators fitted to cars with a discharged / flat battery will fail within 30 minutes. He must make sure his battery is fully charged, if it isn’t, the alternator is not designed to and cannot cope with the demand of handling the vehicles electrics and charging a flat battery. The likely result is an overloaded alternator which will blow the rectifier, rendering the unit useless"

Perhaps it isn't Rhubarb after all. If it is a get out clause, how would they prove that a unit sent by mail order and returned faulty was fitted with a flat battery?
 
They would just claim it had a flat battery and ask you to prove it wasn't.
I repeat, if an alternator is rated at 100 amps, it can deliver it continuously and if the load is demanding more it should limit the current.
I've started hundreds of cars over the years with dead batteries and never has it caused an alternator failure.
If it can't run at rated current for 30 minutes then it quite clearly is not fit for purpose.
 
I have to agree, I've had so many flat batteries but my alternators have always done a good job replenishing the pixies and in 30 years I've never had an an alternator fail.
 
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