Battery VW Beetle

ghostlymoron

ghostlymoron

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Apologies for posting a non-boat query.
I replaced the battery on a 1972 Beetle as it wouldn't start even after charging the old battery. The car then started OK but I noticed when fitting the new one that there was a slight spark when connecting the second terminal which led me to think that there is something drawing current continuously.
I put the old battery on charge for a day using a smart charger (from Aldi's) and have been measuring the voltage over the past 3 days. It started at 13v and after 3 days is still at 12.9v. I am reaching the conclusion that the old battery was OK after all. What do you think?
 
It sounds like the old battery is holding its charge, remarkably well in fact. It does not necessarily mean that it is Ok though. You really should have had it tested with a discharge tester to see if it is capable of delivering the high current required by a starter motor.


The little spark when connecting does indicate some discharge. That needs investigating. Try to measure the current using an ammeter, start with a high range and work down to a low range if not registering on the high range. A knowledge of the current being drawn will give a clue as to what may be drawing it.

Luggage compartment light on would account for perhaps 1/2 amp.
Dont be surprised to find a small current of a few milliamps though . Clock or radio memory (guess its not got remote locking though).

Also check the charging by the alternator (1972 ... not still got a dynamo?? ) Easiest to just monitor the volts and ensure they rise to what ever is specified .. will be somewhere between 13.8 and 14.2 probably.

Familiar scenario though. battery getting on a bit, cold weather,
perhaps not fully charged due to short journeys, heater fan on all the time, heated rear window on, poor connections (I once had to solder all the battery leads, starter motor lead earthing lead end terminals ... no one paricularly bad but a little volts drop at every one added up to the point where I could barely start on a winters morning .. battery then Ok for about another year or so !)
 
ghostlymoron said:
Apologies for posting a non-boat query.
I replaced the battery on a 1972 Beetle as it wouldn't start even after charging the old battery. The car then started OK but I noticed when fitting the new one that there was a slight spark when connecting the second terminal which led me to think that there is something drawing current continuously.
I put the old battery on charge for a day using a smart charger (from Aldi's) and have been measuring the voltage over the past 3 days. It started at 13v and after 3 days is still at 12.9v. I am reaching the conclusion that the old battery was OK after all. What do you think?
Click to expand...

Air-cooled VWs are renowned for starter motor problems. I have lost count of the number of times that I have had to lie under my vans bridging the solenoid connections on the starter motor. For a reason that I have never been able to fathom out, high resistance develops in (probably) the starter switch that prevents full voltage and/or current from reaching the starter motor solenoid connection. If you experience the same problem again, connect a wire or screwdriver between the power and solenoid connections on the starter motor. It will spark but should turn the motor over briskly.

Ways of fixing it more permanently are either to remove the starter wires from the original switch and put in a button to make the connection, or replace the switch, or run a wire from the solenoid connection to somewhere near the battery and touch it on the live terminal if it fails to start on rare occasions.

You can easily check whether a significant current is being drawn by something by putting a meter between the terminal and battery post. A small current may be drawn by a radio, even when turned off.
 
More than Volts

Just because a battery holds a charge does not mean it will give out enough current to start the engine. I have an old car battery which I use for testing stuff, it has held a fair voltage for a couple of months, but I know it will not start a car and has a much reduced capacity.

Likewise old batteries that self discharge in a couple of weeks may or may not start a car if they are fully charged.

My maxim is to 'test it like you use it'.

Hope that helps and good luck with your car.
 
Vic and Vyv have clearly got the aircool t-shirts along the way too.

I would try reconnecting the positive battery lead a few times and see if there is still a click sound each time.. I seem to remember there is an electric fuel shut off solenoid on the carbureteur that reactivates and gives an audible sound when you reconnect a battery?? Don't ask me why 'cos I never reasoned it through..

As said already , an ammeter on the main battery leads and then tspecifically through each fuse will trace a possible discharge current.

As I expect you know, 'German and Swedish' are good for p/exchange starters etc..

And holding down the clutch pedal when you crank gives usefully less drag to overcome in marginal/cold conditions....

Just be grateful its not a 6 volt system !
 
I seem to remember from my yoof that VW beetle's were 6 volt electrics.

When did they go to 12 volt?


And yes. I AM that old :(
 
I seem to remember from my yoof that VW beetle's were 6 volt electrics.

When did they go to 12 volt?
Click to expand...
Yes they were 6 volt. Don't remember when they went to 12 volts. When people wanted them to start reliably and to have good lights I expect.

About 1971 perhaps :D
Seriously it may not have been long before that
 
ghostlymoron said:
Apologies for posting a non-boat query.
I replaced the battery on a 1972 Beetle as it wouldn't start even after charging the old battery. The car then started OK but I noticed when fitting the new one that there was a slight spark when connecting the second terminal which led me to think that there is something drawing current continuously.
Click to expand...

I've seen that on a Beetle as well. I think it was suppression capacitors charging up. Nothing to worry about.
 
Perhaps we should make this a beetle owners thread,

I had one too, XNR 614J, light blue 1200cc
My first car, passed my test in it and took it in to the 100,000 mile club.

Also you might get a small spark as you will most likely have the door open to get to the battery anway and interior light will be on (if you have one working, mine usually did not)
 
Big thanks

Many thanks chaps. Good points about the interior light and capacitors. I've decided not to let on to the VW owner that she might have spent 40 quid un-necessarily. She's had the car about 5 yrs without a bettery change so it was probably near replacement time anyway. When trying to find the cause of non-starting I read the Haynes manual concerning the starter motor which stated 'All this must be done mainly by feel' (p145 para 3) so I decided this was not a route I wanted to go down - specially as it was not my car!
 
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