407 1.6HDi SE Intermittent Starting Problem - 2004 Model. 43,000miles

I bought a Peugeot 407 1.6HDi SE three weeks ago. Since then I have
returned to the car on two occasions only to get the symptoms of a
flat battery when attempting to start. On the first occasion the AA
used their power pack to start it. On the second occasion an obliging
Fiat Punto owner provided starting power.
The alternator is turning out 14.5v and the car can run with the
headlamps on immediately following these failures. On both occasions
the car has been sitting for 20 minutes. Both occasions have been
preceded by long runs each within a day of the failure.
It might be the battery as the car has done 43,000 miles and is 3
years and 4 months old. Has anyone got other ideas? Is there any known
problem with the Peugeot 407 1.6HDi that can drain the battery when
the car is parked?
The car is going back into the garage for the last chance fix before I
demand a refund. They have had one crack at it already. The car needed
a Starter Pack to get it started when I viewed it. I should have
knocked it back then! There were also two missing TPMS tyre valves
which escaped their pre-sale check despite the loud warning. They have
fixed this.

Thanks,
David Rocke

 

Sounds to me the garage is trying too get rid of it (well you got it )
get the batt tested under load,it might be just giving the charge when
ticking over but when everything is on thats a diff matter.or it could
be the alternator bruses working well at low speed and not very well at
a bit more speed,if your not happy keep making your self a pest they
soon get it done.

 

It could also be the battery connections, the symptoms certainly sound like
it. Give them a clean with a bit of emery paper (or similar) and then
smear with Vaseline (NOT grease). That may well cure it.

 

Two main possibilities are the battery itself and a leaky diode in the
alternator.
If you can check the electrolyte level in the battery see if there's one
cell much lower than the others, that's often a give away.
Any auto electricion will do you a proper load test on the battery though.
If the alternator has a leaky diode they may/will run a lot hotter than
usual and may feel warm even when you come to the car cold.
Other stuff to watch for is interior lights or boot lights stuck on or
retro-fitted radio/CDs not switching off with the ignition..
If it isn't the battery itself, you will probably have to disconnect it and
put an ammeter in series with it to see how much is leaking.
If it's running into more than milliamps, you may have to pull fuses till
you find the leak.

Djimbo