Dead Battery

[George Miller]

I have a 1949 Chrysler Windsor that I purchased in November 2005. I put a new battery in the car in December 2005. I had been starting the car every week all winter and letting it run in my garage for about 30 minutes (I would back it up and down the driveway is the weather was good). I let the car sit for 3 weeks, and the battery is completely dead. I need to buy a 6 volt battery charger...does anyone have a suggestion? Also, are these cars grounded on the negative or positive terminal?

[34 Dodge]

George,

My friend put in 3 batteries in his '40 Plymouth convertible in one year. It turns out the the shop kept putting it in with the negative connected to ground. Your car has a positive ground. After we changed the polarity he has had no further battery problems. The only damage was to his radio.

Ken Sobel

[Jon Robinson]

George:

Remember also that the generators in old cars do not behave like alternators in newere cars. Generators do not charge at idle speed. They have to be revved up a little bit. Your car may have been running for 30 minutes, but it may not have been revved up enough for the generator to be charging the battery.

Secondly, as the voltage regulators in these cars are sensitive to heat. As your engine compartment gets hot from the engine running, the charging will lessen, and you'll have to rev it up even more.

It's a good idea to let it run for 30 minutes as you are, but you might want to crank the idle screw up to about 1,000 RPM. The other thing this will do is keep the engine cool in the process. These sixes get hot at the back of the block, and if you rev it up, it'll stir the water around, and the fan will pull more air through the radiator.

JON

[mrpushbutton]

Always, always, always disconnect your battery when you are not using your old car. Install a battery disconnect switch, or one of those "unscrew" type disconnect switches. Then, after you do your start-run regimen (good for the engine) put a small trickle charger on her, overnight. Check the polarity as advised, that's important.

[55PackardGuy]

Another note on winter warm-ups, they may be good for the engine but they can be rough on the exhaust system. Make sure the engine AND exhaust system get plenty warm. If there's still a cloud of condensation coming out the exhaust pipe, there will be moister inside the pipes and muffler if you shut it off, leading to corrosion from the inside while it sits. Very good advice on disconnecting the battery. Not only does it avoid draining power, it can prevent a fire (current draw can be from a short--if it just drains the battery you're lucky!).

[George Miller]

What type / brand of charger do you use? Can all chargers be used with positive ground cars, or do I need a special charger? Do you know of vendor(s) who sell these chargers?

Thanks,

George Miller

[34 Dodge]

George,

Any type of 6-volt automotive battery charger will do. Just connect the POSITIVE (RED) terminal from the charger to ground and the NEGATIVE (BLACK) to the battery and you're all set. Any auto supply store should have a charger. You should be able to buy one starting in the $25.00 range.

Ken Sobel

[mrpushbutton]

George, You can get a fine charger at your local sears store, as stated above, just connect the positive clip to the positive post, and the negative to the negative. The charger doesn't care how your car is wired. I like the 10/2 amp (selectable) type of charger with an automatic shut-off, so the battery doesn't get cooked (overcharging will result in boiling off electrolyte). You use the 10 amp mode when the battery is heavily discharged, and the 2 amp mode to trickle charge for storage loss.

[George Miller]

I purchased a Sears Diehard 71223 automatic battery charger and use it to recharge my battery. The charger indicated that the battery was sulfated; the recharge time, including the de-sulfating process was approximatley 12 hours. I took the car out for its first drive tonight. It started readily after sitting for the approximately 1.5 months. The ammeter indicates a slight charge while the car is driven. Is this normal?

Thanks for your advice,

[mrpushbutton]

Yes, that slight charging state while running is absolutely normal. If it was charging heavily (over 10-15 amps) that would be excessive for a freshly trickle charged battery. Remember, you have a generator, not an alternator (a Chrysler first) that is normal. you will also see no charging when sitting at a light, or idling. that is the nature of the beast.