Date: Wed, 5 Feb 2003 21:06:04 +0100 From: "Johan Beikes" <j.beikesnopsamdoo.nl> Subject: Re: Faulty alternator connection or a nuance of Saabs?
Not quite rubbish. The alternator needs a magenetic field at the stator in order to generate a voltage and start delivering a charge current. The magnetic field builds up by a current supplied by the battery. If the battery is _really_ flat, then the stator magnetic field will be very weak, so a high charge cannot be expected. Not until the battery reaches a certain voltage by the low charging current. So, yes it can take a couple of minutes before high charging starts. Rgrds, Johan "Ian" <dorset_hippynopsamail.com> wrote in message news:b1rfnf$161qbp$1nopsam3332.news.dfncis.de... > > "Jez" <jl.webnopsamorld.com> wrote in message > news:Jo90a.231$pM6.82nopsamfep1-gui.server.ntli.net... > > Hi, any opinions on this would be great: > > > > I've just had a vehicle recovery man jump start my 1988 Saab 9000 and then > > quickly take a charge rate reading which showed the battery not being > > charged. I made a 'phone call and when I returned he said that he had put > > his hand down the back and nudged the alternator and was now getting a > > charge reading. He therefore surmised that there is a loose wire to the > > alternator. > > > > I then drove to my local garage and told them about it, but one of the > > mechanics said that Saabs of about that age don't charge their batteries > for > > the first few minutes, and that this is probably what has happened. He > said > > he's no idea why they're like that, nor even whether they all do it, just > > that he's come across it a few times. > > > > Anyone got any experience or knowledge of this? > > > > Thanks, > > > > Jez > > > > If your battery was that flat you needed a jump start then the alternator > would take several minutes to trickle charge the battery until a suitable > voltage was reached. This is required before any high rate charge would be > sent to the battery, hence the delay for his test equipment to show a high > charge rate. Quite often when a battery becomes very discharged the > alternator will never charge it, an external trickle charger is required. > > The battery not charging for the first few minutes is absolute rubbish, > otherwise we'd all be driving round in our saabs with the battery warning > light on for several minutes after starting! Nonsense! > > > -- > www.stevepipercarelectrics.com > >