| Home  Blogs Help Search Login Register  
« previous next »
Pages: [1] 2 Print
Author Topic: Battery discharging ? ?? ?  (Read 5248 times)
Phillip Wendt
Jr. Member
**
Posts: 29


« on: May 05, 2010, 10:32:54 pm »

Hi all Matra lovers Wink

Ive discovered a problem on my bagheera, i just bought a brand spanking new battery for 100£ but as soon as the car stands for more than 14 days, the battery has discharged, and whenever i have been on a long trip it hasnt charged the battery as much as an amp, what could the problem be ?


Thank you!
Logged
andyowl
Sr. Member
****
Posts: 456


New exhaust "straight through" - good sound!


« Reply #1 on: May 06, 2010, 09:18:32 am »

I have the same problem with all my Bagheeras except the competition car which has a battery isolation switch. That one can go weeks without having any loss of stored electricity because EVERY circuit is disconnected when it is switched off.

That's the clue perhaps. Something may be taking current all the time. Many small consumptions perhaps. If you have an Ammeter (10Amp is best) try disconnecting the positive battery terminal and putting the ammeter between the terminal and the positive cable so that any current being taken has to go through the meter. It will very quickly tell you if that is the problem. If so, where do you look? Takethe fuses out one at a time and see how the current changes. If all the fuses are out and there is still current flowing something connected permanently is the cause. A "process of elimination".

- Many Bagheeras have a clock. This consumes all the time.

- You probably have a modern radio/CD player. Does it have an on/off switch that goes "Click" when you operate it. It probably does not have such an old fashioned switch and it will therefore consume all the time not least to retain the memory of the channels programmed.

- You might have other things switched on all the time. Is there a light in the luggage compartment? Does that stay on? Glove box light?

- Is one of the window switches sticky and causing a window motor to be energised even though the window is fully closed?

Maybe your new battey is faulty? Try disconnecting it and checking it again after 2 weeks? Self-discharging is not unknown!

How about charging the battery? What is the voltmeter reading across the battery when the engine is running? It should be over 13.5Vdc (You need to check this figure - I'm going from memory). I have seen over 14Vdc but that was probably too high! Use a separate voltmeter and do not rely on the instrument panel for this test. My competition car has both the original instrument panel voltmeter and an external one. When the instrument panel is in the centre of the scale the external one shows 14.5V i.e. charging well!

Time to get the meter out!

Andy
Logged

Back in business for fun!
Jon Weywadt
YaBB God
*****
Posts: 962



« Reply #2 on: May 06, 2010, 11:57:22 am »

Hi all Matra lovers Wink

Ive discovered a problem on my bagheera, i just bought a brand spanking new battery for 100£ but as soon as the car stands for more than 14 days, the battery has discharged, and whenever i have been on a long trip it hasnt charged the battery as much as an amp, what could the problem be ?


Thank you!
The clue to your problem lies in your observation that a "long trip hasn't charged the battery as much as an amp" The charging regulator is most like ly the problem. A car can operate for days on a fully charged battery, since you only draw power when starting the car. Once the engine is running the alternator delivers enough power for ignition and lights.
Logged

Matranaut par excellence Cool
JL
Sr. Member
****
Posts: 234



« Reply #3 on: May 06, 2010, 12:03:06 pm »

Hi John
My first port of call would be the alternator or alternator control box if they not a combined unit.
Regards
John
Logged
Spyros
Sr. Member
****
Posts: 323

I'm a real donkey!


WWW
« Reply #4 on: May 06, 2010, 07:03:31 pm »

It's is usually due to earthing issue for the regulator.
They did something stupid to screw it on the aluminium direction
The mix of iron and aluminium generate corosion and the regulator is not to the ground anymore.
They issued several technical buletins to address this issue (see my manual, 4 pages starting at 188)

Of course, this doesn't prevent the alternator to die.
Do you see the light on the dashboard before starting ?
This allows the alternator to start delivering. If the lamp is dead, it will not work anymore.

Logged
suffolkpete
Sr. Member
****
Posts: 456



« Reply #5 on: May 08, 2010, 10:15:11 am »

Quote
What is the voltmeter reading across the battery when the engine is running? It should be over 13.5Vdc
To test the alternator, you really need to have it under load.  Run the engine up to about 2000 rpm and turn the lights on, you should see between about 13.7 and 14 volts under these conditions, although up to 14.4 is acceptable without frying the battery.  Andy's suggestion of measuring the current drain is a good one, but the clock and the permanently on connection to the radio only consume a few milliamps and a half-decent battery will support this for weeks if not months.  Modern car audio systems have two connections, one which is permanently on to support the memory and one which is controlled by the ignition circuit.   Matras, for some quirky Gallic reason, have the radio circuit permanently on, and if this is the case with your car, it could be pushing the current consumption up a bit.
Logged
Jon Weywadt
YaBB God
*****
Posts: 962



« Reply #6 on: May 14, 2010, 09:07:24 am »

[quote author=Jon Weywadt link=topic=1879.msg14294#msg14294

 A car can operate for days on a fully charged battery, since you only draw power when starting the car. Once the engine is running the alternator delivers enough power for ignition and lights.
[/quote]

In trying to diagnose a problem with the ignition light not coming on when I start my Murena, I swapped two wires "+" and "L" on the regulator. It did not help and getting interrupted I forgot to swap the wires back.

No problems starting the car, I drove for 5 days before it no longer had enough juice to crank the engine. I immediately realized what the problem was, but had to get it on jack stands to get under the car and swap the wires back. Problem solved and it charges nicely.

Morale of the story. Make sure you have 12V to the alternator windings when ignition is on. There are a number of diodes in the regulator module on the alternator and one could be bad. A new regulator is available on e-Bay for about 15€.
Logged

Matranaut par excellence Cool
Spyros
Sr. Member
****
Posts: 323

I'm a real donkey!


WWW
« Reply #7 on: May 14, 2010, 11:48:37 am »

A new regulator is available on e-Bay for about 15€.

Jon,

You've to show me this because if it was true I'd buy immediatelly 4 of them.

Regards
Logged
Jon Weywadt
YaBB God
*****
Posts: 962



« Reply #8 on: May 14, 2010, 01:20:57 pm »

A new regulator is available on e-Bay for about 15€.

Jon,

You've to show me this because if it was true I'd buy immediatelly 4 of them.

Regards

They have plenty here:

http://cgi.ebay.de/LICHTMASCHINEN-REGLER-RENAULT-SUPER-5-TALBOT-MURENA-/380186275521?cmd=ViewItem&pt=Autoteile_Zubeh%C3%B6r&hash=item5884de2ec1

It is listed for the Murena, but this part is usually identical on several alternator models. My guess is that they will have one specifically for the Baghera.
Logged

Matranaut par excellence Cool
Spyros
Sr. Member
****
Posts: 323

I'm a real donkey!


WWW
« Reply #9 on: May 14, 2010, 01:35:26 pm »

Bad guess, I'm affraid.

On most Bagheera's, except the very very last ones, the regulator is external to the alternator.
On the really early ones, they were still close to the alternator but the large majority commands a regulator earted on a rusty plate located on the corroded steering.
And no regulator on ebay.
You can find an adaptation, full electronic one but that's it
Logged
andyowl
Sr. Member
****
Posts: 456


New exhaust "straight through" - good sound!


« Reply #10 on: May 14, 2010, 01:41:58 pm »

I purchased an external voltage regulator for Baggy Joe last year. I forget the price but I think it was about 85Euro. Electronic and encapsulated, it fits on the same steering rack mounting as the original electro-mechanical regulator. The auto-electrical engineer who checked the alternator obtained it for me within 48hrs but there was no manufacturer's name on it.

I'm sure  I could get more info if it would help anyone.

Andy
Logged

Back in business for fun!
Jon Weywadt
YaBB God
*****
Posts: 962



« Reply #11 on: May 14, 2010, 04:19:49 pm »

Bad guess, I'm affraid.

On most Bagheera's, except the very very last ones, the regulator is external to the alternator.
On the really early ones, they were still close to the alternator but the large majority commands a regulator earted on a rusty plate located on the corroded steering.
And no regulator on ebay.
You can find an adaptation, full electronic one but that's it
It is obvious I don't have a Baghera Grin

If the regulator is external, are you sure the car has an "alternator" and not a "generator". I know the Baghera is a generation earlier than the Murena, so I guess it could have a DC generator instead.

Hasn't any of you tried to fit a modern alternator on the Bagheras? Surely that would be possible.
Logged

Matranaut par excellence Cool
andyowl
Sr. Member
****
Posts: 456


New exhaust "straight through" - good sound!


« Reply #12 on: May 14, 2010, 05:05:09 pm »

Jon wrote"...Hasn't any of you tried to fit a modern alternator on the Bagheras? Surely that would be possible..."


I think that you think that I think that "modern" is a compliment or good news!

1977 technology is the pinnicle of good technology for people of my generation (I'm not talking about electrical generation either!).

Reliable, repairable, separate components which can be upgraded and replaced (if not actually repaired) individually, rather than complicated, sophisticated, integrated designs only capable of "repair by replacement" at huge cost to the owner and similar profit margins to the dealer.

Modern is good?? I don't think so!

My Bagheeras will be still going long after my (very nice) 2006 Honda Accord Tourer with all it's nice toys, has become "not worth repairing".

Discuss!

Andy

Logged

Back in business for fun!
Spyros
Sr. Member
****
Posts: 323

I'm a real donkey!


WWW
« Reply #13 on: May 14, 2010, 08:09:44 pm »

I can still distinguish an alternator from a dynamo (generator)  Roll Eyes

My Healey is equiped with a generator.
But she has 2 excuses
1) She is from 1963 and the conception is even older
2) It's a British brand (usualy synonym of obsolete conception - Lucas)

But ...
I have to say that her generator works perfectly, the battery is allways holding the charge, ...
And I don't see any reason to update it
Logged
suffolkpete
Sr. Member
****
Posts: 456



« Reply #14 on: May 14, 2010, 09:12:42 pm »

Quote
It is listed for the Murena, but this part is usually identical on several alternator models. My guess is that they will have one specifically for the Baghera.
   
Not sure about that.  There is more than one type of alternator on the Murena, from two different manufacturers.  I would be surprised if it fitted both, and there's no information on the web site to help decide which is which.  Pity really, I've got a Ducellier alternator I'd like to overhaul, but I can't be sure it's the right one, and he doesn't appear to send outside Germany.
Logged
Pages: [1] 2 Print 
« previous next »
Jump to: