Can a car run without a battery

[Shelby]

http://www.starquestclub.com/forum/public/style_images/master/snapback.pngTurborusty, on 07 June 2011 - 08:36 PM, said:

 

Not that the ECU runs off the battery, but the battery smoothes out the voltage to the ECU, making it much happier.

 

 

 

Turborusty

 

this is the most correct answer.

 

I have a degree in electronics engineering if you need credentials to believe what you read.

 

 

 

 

now i don't have any degree's hell i didn't even finesh high school but from what i learn'd under my shade tree was the ECU internaly steps down the voltage to aprox 5 volts , so while the system batt voltage is falling and it will at a near steady rate , most other systems that require a full 12 volts will stop working long befor the ECU turns off or gets unhappy as you say

 

any system design'd to operate at a set voltage and amps will increase it's amp demand as the voltage available to it drops , placeing more and more load on the battery the longer this goes on,, causeing lower and lower voltage to be available,, in this example the fuel pump and or ign system will fail or relays will open long befor the ECu becomes unhappy

 

that may not be the educate'd way of explaining it but thats my understanding of it for what thats worth

[Chad]

it kills the fuel pump and ignition system, so in a wreck, you don't have to worry about sparks and fuel mixing afterwards (when the rescue crew is there)

 

I had to put one in my car for the local track rules cause I have a rear mount, in cabin battery. It needs to have a disconnect within 18" of the battery.

 

Any race car that travels more than 1/4 mile has an alternator. Any race car that doesn't have one probably uses a 16 volt battery.

[The Rabbit1]

it kills the fuel pump and ignition system, so in a wreck, you don't have to worry about sparks and fuel mixing afterwards (when the rescue crew is there)

 

I had to put one in my car for the local track rules cause I have a rear mount, in cabin battery. It needs to have a disconnect within 18" of the battery.

 

Any race car that travels more than 1/4 mile has an alternator. Any race car that doesn't have one probably uses a 16 volt battery.

outlaw, funny cars, top fuel, dragsters, they all go over 1/4 mile.. they have to slow down and come back, lol

 

we use two optimas in a lot of cars that are track only cars. the less hp used to drive accesories the better. the batteries only power water pump and ignition system, as well as the roll control, trans brake, NOS solenoids. work fine for quite a few passes. once the switch is thrown there is no power to the car, it kills the engine as well as prevents sparks from becoming a hazard.

 

Todie, I'm about to mount a kill switch on the camaro. It won't be hooked to anything.. doesn't mean I'm using it for the correct application right?

[Chad]

now i don't have any degree's hell i didn't even finesh high school but from what i learn'd under my shade tree was the ECU internaly steps down the voltage to aprox 5 volts , so while the system batt voltage is falling and it will at a near steady rate , most other systems that require a full 12 volts will stop working long befor the ECU turns off or gets unhappy as you say

 

any system design'd to operate at a set voltage and amps will increase it's amp demand as the voltage available to it drops , placeing more and more load on the battery the longer this goes on,, causeing lower and lower voltage to be available,, in this example the fuel pump and or ign system will fail or relays will open long befor the ECu becomes unhappy

 

that may not be the educate'd way of explaining it but thats my understanding of it for what thats worth

 

 

That's not universaly true, think of a resistor, say a headlight bulb. It's a passive load, reduce voltage and the current will go down, every time. An active load will behave differently.

 

Some passive loads will pull more current as voltage is reduced, but these are only passive devices with dynamic loads. An example of this would be a fuel pump. The regulator dictates the flow rate of the pump, not the input voltage. If you reduce the input voltage but it's still expected to produce 38 PSI of fuel, it will have to do that with more current. Most passive loads are not dynamic.

 

ECU's have active 5 volt power supplies, so those can compensate for most undervoltage conditions, but they still have a limit. auxiliary systems that they count on to opperate don't have this active 5 volt supply, things like the ignitor and coil. the motor won't run when either of those are subjected to too-little voltage, and the motor will stall out, even if the ECU is sitll happy. So yes, technicly the ECu is still happy, but it will fail to keep the motor runing as it's not getting correct signals from other systems.

[Chad]

outlaw, funny cars, top fuel, dragsters, they all go over 1/4 mile.. they have to slow down and come back, lol

 

 

I think everyone knows what I ment.

 

BTW, Top fuel and funny cars cars cut power at the end of the 1/4. Don't need 12 volts to slow down.

[The Rabbit1]

I think everyone knows what I ment.

 

BTW, Top fuel and funny cars cars cut power at the end of the 1/4. Don't need 12 volts to slow down.

lol, but seriously, the alternators only real function is to keep the battery charged. it's not needed. The battery's only function is to store voltage for start up and create a buffer for voltage, so it's more important then the alternator, but still not absolutely necessary.. but you kind of need both really.

 

Oh yeah, I just thought of it, those cars with no alternators.. they're carbureted.. sorry, forgot.

[Killtodie]

On a battery related note. Got a few questions.

 

 

So today I was working on my quest, was in the garage for about 4 hours, during which one of the doors was opened for a combined time of about an hour. When I was done, car would not start, was outputting 9 volts.

 

Another time I left the trunk open and that light completely killed it overnight, nothing, no voltage, not a single light. Got it jumped after a 10 minute charge.

 

One more example my mom's car, which has been sitting for 8 months, my dad would start it ones a week or so and drive it around. During a cold spell the batt died, I took it to pepboys, had them charge it, brought it back and left it inside the house. about 3 months later, I attempt to start the car, batt is at 8volts, I drop it back to pepboys, they charge it but tell me it wont hold a charge but so far it hasnt failed. been 3 weeks.

 

What causes a battery to die like that and what kind of battery is best to use (rating) so it wont die overnight if a light is left on?

[The Rabbit1]

optima dry cell are better.

 

as it was explained to me:

 

There are metal plates in the battery, these plates have a lead coating, they are submerged in sulfuric acid. the charge in the battery actually keeps the lead in place. without a charge the lead starts melting down the plate. this would explain why if you keep leaving a battery without a charge it eventually goes completely bad. little by little all the acid has melted till it is all at the bottom of the battery.

 

Optimas have no lead..

Edited June 8, 2011 by The Rabbit1

[Shelby]

lol, but seriously, the alternators only real function is to keep the battery charged. it's not needed. The battery's only function is to store voltage for start up and create a buffer for voltage, so it's more important then the alternator, but still not absolutely necessary.. but you kind of need both really.

 

Oh yeah, I just thought of it, those cars with no alternators.. they're carbureted.. sorry, forgot.

 

 

sorry but this is not true,, all batterys have a finite life cycle , meaning they can only be discharge'd and recharge'd a limit'd number of times,, this esp true of todays batterys in cars,, theres a huge diff in batterys, take a marine batt , there are more then one type of them what works well for a main starter battery will not work as say a trolling motor battery, why because it is discharge'd many more times then a reg battery,, so they are design'd as a deep cycleing battery all that realy means is it has a life time cycle of charge and discharge much longer then a normal start only battery

 

also under normal use an alt will not fully charge the battery , it's job is to maintain the batterys full charge not recharge it fully ,the voltage reg limits it's ability to do that,, cause of whats call'd surface charge of a battery, the reg will stop chargeing befor the batt is actualy at max charge ,,you can beleave that or not i do not care,, also a 20 chrg time will deff not full charge a battery

 

you can kill a new battery by totaly draining it one time , they just don't make things like they use'd to

[Metric-man]

This thread sounds like a job for, X-Men’s archenemy and his Brotherhood of Evil Mutants.

 

And the vehicles they where used on weren’t all carbureted http://en.wikipedia.org/wiki/Mechanical_fuel_injection#Mechanical

 

I know another question killtodie forgot to ask....

 

Why don't Motorcycles have alternators?

 

If you guys never had any old-school racing friends you probably wouldn't know.

 

(Real old-timers (like Shelby) are not included because they already forgot more than you know. )

 

 

killtodie if you try driving at night without an alternator or with any other accessories switched on you'll find the distance you can travel is greatly reduced.

 

And for the record, you don't need to totally discharge a flooded starter battery for it to be unretrivable.

once the cells reach 10 volts it's time to buy a new battery.

Edited June 8, 2011 by Metric-man

[Metric-man]

optima dry cell are better.

 

as it was explained to me:

 

There are metal plates in the battery, these plates have a lead coating, they are submerged in sulfuric acid. the charge in the battery actually keeps the lead in place. without a charge the lead starts melting down the plate. this would explain why if you keep leaving a battery without a charge it eventually goes completely bad. little by little all the acid has melted till it is all at the bottom of the battery.

 

Optimas have no lead..

Ummm... what?!

 

Have no what ?

 

http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

[The Rabbit1]

Ummm... what?!

 

Have no what ?

 

http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

No LEAD: http://en.wikipedia.org/wiki/Dry_cell_battery#Dry_cell

 

my explanation in that post was about standard lead-acid batteries

Edited June 8, 2011 by The Rabbit1

[Whiplash]

never do such a thing on an efi car. the computer gets it's power from the battery disconnecting the terminal while the car is running is an awesome way to fry your computer.

 

leave that to your 1970 buick.

 

the real answer is it would run either way, but something will probably fry pretty soon.

 

What he said. Removing the Batt. while engine is running could fry the Alt. I've run an engine for a few days without the Alt. with no issues.

 

Also on some engines when the battery gets below 10 or 11 volts the computer won't work.

Edited June 8, 2011 by Whiplash

[Burton]

Here's a good summary..

 

Some cars will run with no battery and alternator power only, some won't.

 

 

Some cars will run off battery power and no juice from the alternator until the battery gets too low, some cars won't.

 

 

 

Trying to run a car in either of these scenerios will cause damage to the alternator or battery as well as other electrical components due to the strain, so it is a poor choice to do either, unless it is an emergency situation.

 

 

Not all cars work the same in these scenerios, it all depends on the age of the car, and the design of the electrical system.

 

 

One of those deals where a Ford is a type of car, but not all cars are Fords.

 

 

 

Do you and your friends just sit around and speculate on hypothetical situations that can damage cars? Seems like a waste of time to me.

Edited June 8, 2011 by Burton

[UlrichWolf88]

ok trying to put this very simple , so CAVE MAN CAN UNDERSTAND IT

 

 

Oh, god, that was the best laugh I have had all day. And I needed it too, because it's been a crappy day so far.

 

'Preciated!

 

Tim

[unforgiva31e]

No LEAD: http://en.wikipedia.org/wiki/Dry_cell_battery#Dry_cell

Actually: http://www.optimabatteries.com/product_support/faqs.php#productInformation

Q: Why the low rate of self-discharge?

A: Mostly this is due to the purity of the lead in the OPTIMA plates.

Optimas are a spiral-wound Absorbed Glass Mat battery. Same Pb-Acid reaction, different package.

 

One of the reasons Pb-acid battery performance degrades when they are deeply discharged is because of sulfation. During discharge, the lead oxide cathode and lead anode both become lead sulfate, recharging is suppose to revert everything back to lead oxide, lead, and the sulfuric acid electrolyte. However, once some of the lead sulfate has crystallized, it not easily restored. In addition to not giving you back 100% of the reactants when the battery was new, the build-up of lead sulfate crystals can fill pores in the lead plates, reducing surface area and capacity. Growing crystals can also break off pieces of the anode/cathode (so can vibration), also reducing capacity. Simply put: batteries dislike heat, vibration, and being deeply discharged. The AGM construction of Optimas mainly addresses vibration, their layout may also have a small advantage in thermal management.

[Shelby]

Oh, god, that was the best laugh I have had all day. And I needed it too, because it's been a crappy day so far.

 

'Preciated!

 

Tim

 

 

glad to have help'd your day out,, but as you see i fail'd http://www.starquestclub.com/forum/public/style_emoticons/default/blink.gif

oh well par for the course these days http://www.starquestclub.com/forum/public/style_emoticons/default/wink.gif

 

but on a good note MY VERTIGO seems to have reced'd ya http://www.starquestclub.com/forum/public/style_emoticons/default/smile.gif

Edited June 8, 2011 by Shelby

[The Rabbit1]

Actually: http://www.optimabatteries.com/product_support/faqs.php#productInformation

 

Optimas are a spiral-wound Absorbed Glass Mat battery. Same Pb-Acid reaction, different package.

 

One of the reasons Pb-acid battery performance degrades when they are deeply discharged is because of sulfation. During discharge, the lead oxide cathode and lead anode both become lead sulfate, recharging is suppose to revert everything back to lead oxide, lead, and the sulfuric acid electrolyte. However, once some of the lead sulfate has crystallized, it not easily restored. In addition to not giving you back 100% of the reactants when the battery was new, the build-up of lead sulfate crystals can fill pores in the lead plates, reducing surface area and capacity. Growing crystals can also break off pieces of the anode/cathode (so can vibration), also reducing capacity. Simply put: batteries dislike heat, vibration, and being deeply discharged. The AGM construction of Optimas mainly addresses vibration, their layout may also have a small advantage in thermal management.

thank you for the added info

[Metric-man]

No LEAD: http://en.wikipedia.org/wiki/Dry_cell_battery#Dry_cell

 

my explanation in that post was about standard lead-acid batteries

 

I think you've been misinformed (in the past), and or some individuals are misrepresenting their product.

 

http://i15.photobucket.com/albums/a361/mzcmdr/optima_YELLOW.jpg

 

http://www.dcbattery.com/optima.jpg

Edited June 8, 2011 by Metric-man

[Maxzillian]

I know another question killtodie forgot to ask....

 

Why don't Motorcycles have alternators?

 

If you guys never had any old-school racing friends you probably wouldn't know.

 

(Real old-timers (like Shelby) are not included because they already forgot more than you know. )

 

Most motorcycles don't user alternators technically, but they still used a device that serves the same purpose: the stator. Any electric start motorcycle has to recharged the battery somehow! To answer your hint and expand on it a little, motorcycles that are generally under 4 cylinders and not fuel injected use one section of the stator as a pulsing power source that operates and or charges the ignition system. These are often paired with a capacitive discharge module as a method to temporarily store the energy and dispel it over a much shorter duration with higher intensity. Additionally the modules often serve as a means to create a timing curve and act as a rev limiter. Older motorcycles simply used a points switch along with the power source to charge and discharge coils.

 

Most modern street bikes, however, employ a system more akin to cars where every ignition device gathers power from one source, the battery.

[Dad]

Oh for Gods sake...... one more thing, can you mix tap water with distilled water and still maintain a charge to start the car then disconnect the battery to run on the alternator?

 

Dad

[carguygibby]

Oh for Gods sake...... one more thing, can you mix tap water with distilled water and still maintain a charge to start the car then disconnect the battery to run on the alternator?

 

Dad

 

Don't do it Randy! If it's anything like mixing different weights of oil it's got to be a recipe for disaster!

 

Colin

Edited June 9, 2011 by carguygibby

[Shelby]

dang near every gas motor in the last 20 years , lawn mower, pressure washer, weed eater,, 4 wheeler, etc has use'd a basic alternator to provide ign spark and charge the battery if use'd ,,it's a stator winding built arround the fly wheel and use's a small voltage reg to charg the batt and acap discharge system to fire the plugs , just like an older boat engine

basicly a magnedo but with more windings and a couple diodes

[Mnementh]

Here's a good summary..

 

Some cars will run with no battery and alternator power only, some won't.

 

Some cars will run off battery power and no juice from the alternator until the battery gets too low, some cars won't.

 

One of those deals where a Ford is a type of car, but not all cars are Fords.

 

 

I drove a junk '77 Ford LTD to the salvage yard & removed the new battery while it was running. So that last statement confused me...

[Metric-man]

Most motorcycles don't user alternators technically, but they still used a device that serves the same purpose: the stator. Any electric start motorcycle has to recharged the battery somehow! To answer your hint and expand on it a little, motorcycles that are generally under 4 cylinders and not fuel injected use one section of the stator as a pulsing power source that operates and or charges the ignition system. These are often paired with a capacitive discharge module as a method to temporarily store the energy and dispel it over a much shorter duration with higher intensity. Additionally the modules often serve as a means to create a timing curve and act as a rev limiter. Older motorcycles simply used a points switch along with the power source to charge and discharge coils.

 

Most modern street bikes, however, employ a system more akin to cars where every ignition device gathers power from one source, the battery.

Maxzillian you should have used the complete quote then you would have answered the question correctly.

 

You need to name the (original) archenemy of the X-men to get it right!