Im confused.

1.) True Or False...

Your only using your battery to start the car, and when the engine is off. The only time your battery is drained while the engine is on is when your alternator cannot keep up with the demand of whatever is being powered...

2.) If it's true, does the current from the battery add onto the current of the alternator (14 volts) or does it just work off of the battery? (12 volts)...also, if that were the case, wouldn't it be a good thing to have two batteries for RUNNING the engine, NOT just for playing music with the engine off, especially if you have two identical batteries and it would take the same amount of power from each one divided by 2 as it would from one?


3.) If it's all false, how can an alternator let's say rated at 200amps be able to handle a system with over 200 amps? Doesn't that mean it needs current from somewhere else?

 

1) False

2) n/a

3) b/c the amp isn't continuously pulling 200+amps. That is why most people can get away with a much smaller, say 105-115amp alt. The majority of the time you will be using less than the maximum demand allowing the battery time to charge.

 

Ok, I understand for #3. How is #1 false?

 

You said, "Your only using your battery to start the car, and when the engine is off."

The battery is in use any time something electrical is activated, either by you or automatically. The battery is not idle after starting the car. It is very much in use.

 

so why does everyone say your car is only using the alternator to power everything once the engine is running?

 

Misinformtion. The alternator is not directly connected to the electrical system if the battery is removed. There is only one power(hot) wire on the alternator. It feeds directly to the battery which acts as a buffer/regulator for the vlotage.

Have you traced these wires yourself? It will help you understand the flow.

 

Actually, you need to trace the wires yourself. The alternator is directly connected to the electrical system. The alternator's (+) cable connects to the (+) post of the battery which happens to be also connected to the rest of the car.
Most alternators of today have regulators built inside. A battery does also function as buffer as you said. It is really there for backup if something with alternator you can still get a couple of miles off the battery. Also, at low RPM's alernator do not put out much current in which case a battery will get a little bit of a work out.

The car actually does not need the battery to keep the car running. I've actually tried this myself. I was able drive around the block without a battery in the car at all.


shyheim07

1) this is partially true... the main purpose of the battery is to start the car
2) A battery doesn't add on current in most cases, it normally takes away current. Batteries discharge over time even with nothing connected. Alternator recharges the battery. If you introduce another battery this will give alternator more work as it will have keep two batteries charged instead of one.
3) Once you go over the amount of current the alternator is able to put out than the current will come from the battery. This is the point where people will notice "dimming"

 

I stand corrected.

 

ok. so lastly, if all your battery does is start up you car, why does everyone get kinetiks and yellow tops and such. if your not in comps and dont play your music while the engine is off, cant u just settle for a regular battery?

 

bump

 

I prefer to spend double the price and have a yellow battery that weighs more under the hood. That's my logic...

 

Bah, let me rewrite this i did it all quick at work

 

so, doesn't that make my first statement true?

 

Heres my cleaned up battery spiel.

1. You can never buy too good of a battery. Yellowtops and Kinetics are great deepcycle batteries. This means you can deplete and recharge them around 1000 times before you ruin them. This makes them perfect for sound compeitiors because they also have a higher amperage rating and can be depleted by large sound setups and not be harmed.

2. With your awesome battery installed, you can now start your car, yay!.

3. As it was stated you could driver your car without the battery? I dont know i havent tried it, i wouldnt recommend it though. How you got your car to run is beyond me, and well, doesnt make any sense lol.

4. The battery in your car is always being recharged, i would assume. In a perfect world where you didnt modify the car, the alternator will always be able to keep up with all the electrical accesories in the car.

5. If you add more accessories than the alternator can support amperage wise, you begin to deplete the battery because its a source of energy until the battery is dead and can no longer support anymore current whereas the alternator would begin to struggle to recharge the battery in a system thats drawing more current than the alternator or battery can produce.

6. I would assume, that after all these years i have been playing on my car, that the battery supports a much larger role than it's being given credit for. I would assume, that as you draw current in your car, it is comming from the battery which is being recharged by the alternator. If the alternator cannot support the current load, the battery dies and you have no power. If the alternator is large enough, the current supplied to all of your electronics will be stable and your battery will stay charged and all is kosher.

7. When your car is off, you are draining the battery bud.

8. When your car is off, the electrical system runs at 12 volts unless you have a special battery that produces a higher voltage. When your car is on, you alternator puts out a voltage of 13.1-14.4 volts which is pretty much an industry standard. That means that your battery is being charged between that voltage range, which is not uncommon for a rechargable battery. Go look at your cell charger and see that the charging voltage is higher than the output voltage on your battery,. This is how your car tries to maintain a full battery for you everytime you start your car. Because the alternator voltage spetrum is betwen those two voltages there abouts, the output on your battery is now that high because the circuit with the alternator was created and thats the voltage being produced.

9. Multiple batteries work, but when you do that, you need a battery isolator so that the alternator will sufficiently recrage one battery and move onto the next inline. A bunch of quarter charged batteries isnt gonna do it. I would assume that these are run in parallel with eachother because if it was in series, you would add up the voltages. If you run them in parallel, its like jumping another car, the voltages stay the same, but you are increasing the overall capacity of amps.

10. There is a way to calculate how many amps that your amplifier uses, or any product that expends energy in the form of wattages, so you could see at peak, how many amps would be drawn.

11. The big 3 is very important. You upgrade the battery, alternator, and ground wires when adding a sound system or what not. To be honest, upgrading all 3 of those anyways would hurt the car. Alot of power is actually bottlenecked in the groundwires which are always so conveniently just small enough to carry a load. The larger the wire, the more freeflowing the electrons can be. When a wire gets hot, that means that the electroncs flowing through are hitting eachother and this friction causes heat in the wire. With a larger wires of proper size, you will always notice the wire is cool, this is because the electrons arent creating friction.

Blah, there we go to the rewrite

 

that write-up needs a sticky...

 

You can settle for a regular battery. Keep the one you got till it dies than it is up to you get something better. I personally followed everyone else and I got a optima red top which is their starting battery. Mine is 4 years old now. The other cheap batteries I had only lasted 2 years (energizer and pro start). I felt a lot better knowing that I have a 3 year warranty which most batteries don't offer The yellow top only has 1 year warranty. I heard a lot of good things about die hard batteries as well.

 

I wound up buying a non-optima because autozone didnt have it at the time, and well in the end i think the issue was truely the starter, but blah, it was the original battery and it did two years in AZ. Extreme heat also degregates the battery quicker.


I tried to get a red top but they didnt have it. Red tops are very awesome batteries, but arent deepcycle. If you arent boasting a huge system and your alternator is large enough, a yellowtop isnt needed

 

The reason I started this thread is because alot have said that the battery is not in use while the car is on. But i believe when you have a larger load than the alternator can handle, the battery is brought in to help with the rest of the amperage needed.


In bold, I say thats true because I have drained out my battery while the car was running when I had 2 L7s on a Kicker 1000.1 mono amp + the 4 channel. I would turn the system off, and the battery would start to recharge again. That was about 5 months ago, which I think explains why my alt went last week. If i started draining the battery down, that means the alt could not keep up so there for it's trying to recharge the battry again. I think if you have identical batteries, they drains equaly...

I wouldn't recommend it either, but with a stock setup it's possible, done it before. Your not gonna be able to start your car without a battery...so you can unhook the cables and it ill still run becasue the aternator has current running through the wire to your positive terminal which is where your factory wiring is also connected. You always (daily driver wise) want your stock accessories connected to the alternator, which is why i think they have those warning labels when you buy a battery with side terminals thats says "do not connect stock accessories to side posts" or sumthin like that.

I'm not heavy on electronics, but i wanna figure out how to get this muthaf#@kin power for my system. i'm strung the idea that more batteries = more amperge support, alternator on or off...but everyone has different views. Who created the car's electrical system, i would like to know.

 

Resurrected....

Ok. So for about 2 weeks I have been running my system faithfuly. I have one Kinetik HC 1800 in the hood, 200 amp alt and err the 3 amps and subs. So my voltage moves of course....First four days, never dropped below 13.2 volts, after that, the lowest it goes is 12.8 volts.

That was while the car is on...

When the car was off, I ran the thing, same songs, same volumes, same gains etc. first four days it dropped to 12.5, after that...down to 12.1...

So, I'm gonna think my battery is draining while the car is on...

I have the big three, grounding kit, upgraded alt and all...

So should I get a cap...or another battery for the trunk? or both?

 

My car drains a brand-new or otherwise charged battery while driving.

I thought I had a parasitic drain problem, found a sticky trunk release switch, fixed it, and metered my turned-off current to only 3 ma.

But the car still drained a brand-new Optima from 12.6 volts to 8+ volts and left me stranded.

When the car is running the alternator tests at 14 volts (measured at the battery terminals). I still suspect the alternator, possibly because that would be easy to fix, but also because it's hard to see why there would be such a drastic drain on the battery if the alternator were functioning when the car is turned on.

Help would be appreciated.