How to start an automatic car with dead battery?

[Pyree]

Like the title says, "How to start an automatic car with dead battery?"

More specificity, if I don't have another battery or power supply to swap, charge or jump start the car for me, can I start the car mechanically? I read those article on how to roll it down the hill, push it or use a rope to spin the wheel, but they all involve the clutch, so that means it is for manual cars only?

 

[wip99gt]

There's really nothing you can do other than a boost. I guess theoretically you could remove the belt from the alternator and use something to spin it really quickly for a while. At the same time you'd need a 9v battery to send power to the excitation wire to the alternator. I think that would work. Maybe attach a cordless drill to the front of the alternator and spin it for 20 minutes or so. Remember this is all theory and off the top of my head. I am going to try this at my shop in the next couple days just to see because I'm curious now.

 

[Pyree]

So what's the result? What works and what doesn't work?

 

[wip99gt]

I'm an oilfield mechanic. I got the one call and spent all my week up at the Zama Lake Project. All my shop time was spent getting my truck ready and getting out ASAP. The equipment that went down costs the company $250k a day when down. I fly to my parents house tomorrow and am back to work on the 31 so will be able to try it that day for you.

 

[Pyree]

Oh ok. Do what you need for work and family first. Don't worry about me. I can wait.

 

[wip99gt]

I tried it and while I did see some voltage I don't think my drill is fast enough to do produce the 13v+ you want to charge with. Now with one of those new dewalt 20v cordless drills as they claim 2000rpm. Also I'm thinking you'd need some sort of resistor to control the draw as without it the alternator will load up and the drill couldn't handle it. So the experiment was a partial success as it is doable, just impractical. I'm thinking it'd just be much easier and cheaper to keep one of those booster packs that you plug in to a car lighter in the vehicle as the drill alone is $300 and one of those boosters is $60.

 

[Declan Kreitmayer]

We should mention a few safety precautions here. First, make well sure that you can release the rope as soon as the engine fires, or you'll quickly be introduced to the front fender well. Second, don't waste your effort on an automatic. There isn't a power in the 'verse that can cause a slusher to turn over its engine.

 

[Declan Kreitmayer]

A car does not have to be running in order to put in into gear. You can put your car into neutral by turning on the key first. Once the key is in the on position, you will be able to move the shifter to the neutral position. If your car is a standard transmission, you should be able to pop start it from the neutral position and get it to a repair shop for a battery replacement.

 

[wip99gt]

A manual is easy to start without a battery. An automatic, not so much. I was attempting to see if it was possible to get enough amperage to start a car by using a drill on the pulley of an alternator and a 9v battery on the excitation wire. What I found was an initial voltage of 8v which slowly lowered to 6.4v. It would not be enough to charge the battery. I know the 9 volts does provide enough power to excite an alternator as I've tried that before, it's just the drill can't handle the speed.
It was just something that Pyree was thinking about and since I have plenty of alternaters at my disposal I thought I'd give it a try.

 

[leeb2013]

surely it would be easier, cheaper and safer to spend $60 on a booster battery, or is this some kind of experiment?

 

[wip99gt]

It was just an experiment. We were talking about how to start an automatic car with a dead battery and no booster. I've used 9v batteries before to excite alternators before and thought a good cordless drill might be able to spin one at a fast enough rpm to create enough power to charge a battery to start a car. If you read the above posts it doesn't work.

 

[Declan Kreitmayer]

If you mean 'jump-start' as in, 'with battery cables,' yes, absolutely. In fact, this would be the preferred method of emergency-starting a vehicle with a dead battery.If, however, you mean to 'push-start' an automatic transmission vehicle, DON'T!! It can be done, but the risk of damage to the transmission is so high that it should only be done in extreme emergency. The same way you jump start a car with a manual transmission.

 

[wip99gt]

Please read the other posts in this discussion. I meant to try charge the battery by the alternator not push start a car. I have been a journeyman mechanic for over a decade so I know how to start a car. The question Pyree asked brought up an idea I had wanted to try.

 

[homerj1]

you can damage the car by starting the car without battery.

 

[wip99gt]

Any vehicle with a ecm then yes but an older engine with a carb can be done. Sprint cars run with no battery, or starter, and no transmission. It's just that with newer vehicles having all sorts of electronics the battery works as a filter as well for any voltage spikes/droops it can see.
Again if you read the posts the test was for a car with the battery in still, just dead.

 

[Declan Kreitmayer]

Try to rotate the crankshaft manually or with an auxillary engine.

 

[wip99gt]

With the compression of new engines hand cranking it would be pretty tough. If there was an auxillary engine around then you'd most likely have something creating voltage like an alternator and would just be able to boost it.

 

[Declan Kreitmayer]

Take the emergency brake off and begin your roll while holding the clutch in. Make sure the car is in gear. Keep holding the clutch in as you continue rolling. Communicate with your helpers at all times and maintain control of the steering wheel. Pop the clutch after the vehicle gains enough speed. The car should be in first or second gear. A first gear start will be jerkier than a second gear start the faster you are rolling. Between five and ten mph should be sufficient enough speed kick the transmission in. If the roll start doesn't work bring the car to a stop by pulling the emergency brake and pressing the brake pedal at the same time. Repeat steps one through five, only this time wait to pop the clutch until you gain a little more velocity. If that doesn't work it's time to call a tow truck.

 

[wip99gt]

It's an automatic.

 

[wip99gt]

double post

 

[Jasmine23]

Good information. Thanks for the post.

 

[Declan Kreitmayer]

You can jump a dead car battery in your automatic car for a lot less than you think and you won't need help from anyone else. Otherwise you have to start your car with booster. I’ve already apply this formula on my BMW 335i when I found the battery was dead. I called up to Rwc glen Waverley & they apply the above mentioned technique to start my car. It was ok now after few days I repaired car battery & it is running well now.

 

[sachu_company]

Car required 10 ampere power to start the engine. So if battery is dead you can try two thing.

1. Start the car by pushing.
2. Start the car engine with the help of rope or some belt. People use this tricks to start their tractor.... Jeep... As well in machine which is used to remove the juice of sugarcane.

So try this

 

[johncarterjc554]

i dont think that there is any other way to start your car.

 

[sindako]

Only Jumper Cables ,
The Oly car I've ever say to Be Ran On Dead Battery with an Automatic transmission was the Mercedes W123 ,
it Had a 2.3 carburetor Engine . Damn that was A Nice Car back then