These electrical gremlins can drive us nuts! As it turns out, it was the
battery causing the over charging. It was hard to diagnose because the
battery seemed normal. I brought it to Auto Zone and they tested it every
which way and declared it fine. I asked the guy to put it on a charger and it
was drawing a lot of amps. I'm guessing there's an internal short in the
battery. Bought a new battery and just took a great test ride along Lake
Ontario.
Thanks for all the advice.
Ned Paulsen
1960 BN7
Webster, NY
-----Original Message-----
From: Roland Wilhelmy <rwil at sbcglobal.net>
To: Bob Spidell <bspidell at comcast.net>
Cc: npaul72464 <npaul72464 at aol.com>; healeys <healeys at autox.team.net>
Sent: Mon, May 23, 2011 4:10 pm
Subject: Re: [Healeys] BN7 over charging
I don't think it is possible to overcharge a car battery at 13.5
volts. If I remember right, 13.8 is the nominal charging voltage at
full charge. So at 13.5 volts the battery is not likely to be
accepting a high current charge forever, or even being fully charged.
Therefore, if the current is about 30 amps, the current must be going
somewhere else, like a short or crummy connection somewhere. I'd look
for something that is hot that shouldn't be hot.
It isn't clear to me from what you have said, Ned. At, say, 3000 rpm
is the voltage still 13.5? Or has it gone bonkers at 14 to 15 volts?
If the voltage never goes over 13.5, then the battery is not being
overcharged.
-Roland
On Mon, 23 May 2011 19:01:22 +0000 (UTC), Bob wrote:
::Once again my ignorance of the 'mid-year' Healeys makes its existence known
(I
think my BJ8 has a three-coil VR but, actually, it's been a while since I
opened
it up).
::
::13.5V at the battery seems a bit low, which makes sense given the large
current draw. My VR knowledge isn't immense; but I did study them some when my
Dad's fire engine's single coil VR wasn't working properly. That engine has
some
circuitry in the generator to limit current output.
::
::My guess is the generator has a problem. There may be some diagnostic tests
in
the manual, or online somewhere (maybe disconnecting the 'F' lead momentarily,
but research this first lest you let the smoke out). There should be something
to limit current; holding a constant voltage won't limit the generator output
if
there's excessive current draw.
::
::Is your ammeter wired in series with the generator and the battery? It's
conceivable the battery has an internal short.
::
::Bob
::
::--------------------------------
::Bob Spidell - San Jose, CA
::
::
::
::Than ks a lot for the reply, Bob. My regulator is the two coil type and I
replaced it with another and the amperage was still reading near 30. I
replaced
the ammeter with another I had and that still read high. There are about 13
1/2
volts at the battery at 1500 RPM. Just over 12 volts at the battery with the
engine off.
::
::Ned
::
|