Re: Dead alternator .. again?

On Fri, 04 Jan 2008 00:43:42 -0000, Dave Plowman (News) <dave@xxxxxxxxxxxxxxx> wrote:

In article <xn0fkrcvnm9sij001@xxxxxxxxxxxxxxxxxxxxxxxxxx>,
steve robinson <steve@xxxxxxxxxxxxxxxxxxxxxxxx> wrote:
Dave Plowman (News) wrote:

> In article <EOKdnf-MqfFwseDanZ2dnUVZ8umdnZ2d@xxxxxx>,
> Coyoteboy <coyoteboyuk@xxxxxxxxxxx> wrote:
>
> > "Dave Plowman (News)" <dave@xxxxxxxxxxxxxxx> wrote in message
> > > Don't be stupid. It's a rare car indeed that doesn't suffer a flat
> > > battery at least once in its life. If every time this happened the
> > > alternator burnt out there'd be an outcry.
>
> > In general use the alt is not designed to output max current, like
> > with any electrical item they are spec'd for general use and can
> > deal with periods of extended output, but extended periods of
> > extended output will stress an aging component.

> Many cars will get near the maximum output of the alternator when
> running with lights and heated rear window on, etc. Alternators are
> specced to work at their maximum.


Only on a small duty cycle usally backed up by the battery

Not so if you're in the North of Scotland etc in a dark cold winter.
Indeed one car I owned couldn't balance the full load. As standard - no
extras.

> > The OP mentioned the alt was a recon
> > unit - often recon companies will leave any functioning hardware and
> > replace only the faulty/worn item - this is how running it at max
> > current for a long period (i.e. dead battery, not just a one-off
> > flat battery) could cause problems.
>
> Then don't buy crap re-cons. Is that your job? You seem to be making
> excuses for them.
>
> > I never once suggested that a single,
> > one-off flat battery would cause a problem.
>
> > Consider, if you will, running your home stereo system at full
> > whack for 24 hours - sure it can do it for a short period but it
> > wont be too long before you melt your voice coils and/or cook the
> > amps due to the extended duty cycle, not due to the peak
> > performance.
>
> Any semi decent amplifier will run all day at it's maximum rated
> continuous output. If it won't it's cheap rubbish. Speakers too at
> their maximum rated input.

Most amplifiers have both a max output and a max continous output , the
continous output is usally falls between 60 and 80 % of the full
output same with generators or any other piece of electrical equipment .

Depends on who makes the amplifier. I agree you can have a higher peak
output if the heatsinks are inadequate. Make them larger and that becomes
continuous. You pays your money... Many PA amps are designed to be run
beyond their stated output without damage - as that's how they'll get
treated.



However none of the decent modern ones will run at peak output continously, they all shut down "gracefully". But if you're running a PA amp at peak you'll be clipping anyway.

It is very rare that the max output and continous output are identical
on any peace of equipment

Plenty of things I can think of. A light bulb. Electric heater without
thermostat. Etc etc.


.

Relevant Pages

  • Re: Dead alternator .. again?
    ... It's a rare car indeed that doesn't suffer a flat ... > extended output will stress an aging component. ... Only on a small duty cycle usally backed up by the battery ... On a fairly high duty cycle on most cars. ...
    (uk.rec.cars.maintenance)
  • Re: Dead alternator .. again?
    ... battery at least once in its life. ... alternator burnt out there'd be an outcry. ... extended output will stress an aging component. ... continuous output. ...
    (uk.rec.cars.maintenance)
  • Re: Ping Mrcheerful
    ... so if we assume that the drains are being measured correctly then that leaves battery and/or charging. ... What is puzzling is the fact that it can go for days/weeks/months without any problems, then it will suddenly have a completely flat battery. ... Flat as in not enough charge left to even pull the starter solenoid in and this can happen overnight. ... All the driver can leave on accidently is the parking lights, which would be noticeable in the dark garage, or the interior lights/glove box/boot light etc.. ...
    (uk.rec.cars.maintenance)
  • Ping Mrcheerful
    ... I am sometimes finding the battery completely flat when I try to start the car, sometimes it has only been left overnight and had been fine the previous day. ... It has done this reliably every time I have checked it, but obviously I cannot leave a 1amp maximum range meter in circuit as a fixture due to the starter load and other loads. ...
    (uk.rec.cars.maintenance)
  • Re: MDD G4 dismantling question
    ... what sort of thing might have been the trouble - it's not like there's ... Actually the 6100 was bad with the batteries, if it was slightly flat it ... 475s won't boot with a flat PRAM battery. ... this wasn't a `flaw of the early PPCs' so much as ...
    (uk.comp.sys.mac)
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