22

A rounded bolt is not a reason to junk a car. The numbers you're quoting sound fine for an alternator; if it was below 12V, I'd be worried. If you're still concerned, take the car to a spares store and ask them to check the battery and alternator. When it does come time to change the alternator, getting the bolt off would not take a lot of extra time; there ...


21

It's because of a couple things: The battery is very dead and the alternator cannot put out enough power at idle RPMs to run the whole system and charge a battery. This leads to a lack of power which may kill one or more systems most likely the spark "ignition" system since this takes the most power and is necessary to run the car. In Fact you can remove ...


19

Your question is difficult to answer without you knowing the inner workings of an alternator. The basics. If you move a magnetic field near a coil of wire the electrons in the wire get excited and electricity will be made. The amount of electricity made depends on the size of the magnetic field and its speed. The bigger the field and the faster it's moving ...


18

I can't give you numbers or calculations without some work, but I can tell you than energy is never free. Cars have an A/C compressor that is mechanically driven by the engine because this is the easiest way to get the job done in a typical consumer car. An A/C compressor actually takes a huge amount of energy to operate. In fact a central A/C unit for a ...


18

Cost is the main reason. An alternator that can provide full charging current would be far larger requiring bigger rotor and stator windings. This would make it more expensive and heavier. The manufacturers are using the fact that you only spend a small amount of time idling compared to driving to their advantage. Most cars are designed to cruise at ...


14

Great question! Taking a few minutes to think through this logically should come up with something. First of all, realise that a larger battery with a higher amperage (CCA) will not cause any problems on the drawing end. In other words, you're not sending too much electricity to some component or something. The higher amperage simply means that more ...


13

Well, Teslas (and presumably other all-electric cars) have A/C so it's not impossible, but A/C takes a fair amount of power. On the other hand, Teslas store a lot of energy. The A/C is something like 2.4kW which is about 8,000 BTU/h or about 3HP. So using an electric motor on a conventional car might give you a few more HP briefly, but the alternator has ...


12

Given all the inefficiencies, is it "free" to plug in, say, a smartphone into a car to charge while I am driving? Short answer: no (but it's so hard to measure the impact that it be hard for you to tell). Remember, the alternator has to power everything connected to the electrical system. Charging the battery is a big load at first but drops off as the ...


11

Most of the time a ground loop is the cause of this problem. This problem is common especially if your stereos speakers are amplified, and can be fixed my making sure that your stereo unit and/or amplifier have a good ground connection. This can be done by either finding a more direct ground connection to the cars frame, sanding the area around your ground ...


11

Absolutely yes. I sell alternators all day every day - and a poor battery is often the root cause of alternator failure. A battery with a short in it will cause the alternator to run at full output for extended periods of time, if not continuously - and they are not built to do this. Alternators the world over are built to supply an initial high current, ...


11

To directly answer this question, no it won't work and you run the risk of damaging your alternator if it is good while doing so. The test you are asking about was used quite successfully with generators, but should not be used with alternators. Alternators are internally regulated. When you pull the battery lead, you run the risk of killing the regulator. ...


9

Yes for the most part an AGM is a drop in replacement for your standard Lead Acid Battery. The charging voltages are almost identical. You are correct that they have a lower internal resistance and can be charged at a much faster rate. This shouldn't cause a problem on the majority of vehicles as the wiring in the car is designed to handle the maximum rated ...


9

Since you have a battery which isn't that old (most batteries have about a five year life span), I'd suggest you put it on a charger and try to recharge it. This will allow the battery to come back to full charge without putting an undue stress on your alternator. You have to decide if the time spent in recharging the battery is worth your time. To me, ...


9

Lead sulfate crystals form on the battery plates as the battery discharges. As the battery becomes more discharged the crystals go from being soft and fluffy to much harder. Recharged in time, the lead sulfate is converted back into sulfuric acid and lead. A month is entirely too long for a battery to remain discharged. Reversing a serious sulfation ...


9

The short answer to your question is no. As @JPhi1618 noted, the compressor is mechanically driven. Without the compressor you don't have any cooling. The AC runs by changing the state and pressure of a liquid, and compressing the liquid is a big part of that cycle. If you bolted an electric compressor onto the car you would have to find a way to switch ...


9

For most of the time, the battery doesn't provide any electrical power to the car. All the power is coming from the alternator. Think about it this way: the alternator probably has a maximum current rating of say 90 amps. For a typical "standard size" 40AH battery, that amount of current would flatten the battery completely in less than half an hour, so it's ...


8

So, bear with me on this and maybe I can help. Mind you, none of what I'm going to say is going to be easy to do, but that is because your issue is not an easy one to solve. The main problems I see here with any solution is alignment and distance from any mounting point I can discern. My main thought here is you need to get the alternator connected back to ...


8

An insufficiently-charged battery would explain what you're seeing: the unresponsive throttle is because the throttle is electronically-actuated (at least that's what eBay reckons) Not sure about the Sentra, but airbag and engine oil lights can turn on due to insufficient voltage the engine will stall because the fuel injectors need electricity to correctly ...


8

In an alternator there are two major components; the stator and the rotor. The rotor has a coil wound on it. By applying a current to that coil a magnetic field is formed and then spinning the rotor electricity is excited in the stator. Because the rotor needs to spin while mainaining electrical contact for the coil slip rings are used. There are normally ...


8

A battery that has an internal electrical short, usually one of the plates has come loose and is touching its neighboring plate will cause the alternator to work much harder than normal. This can shorten the life of the alternator. This condition is usually discovered quickly as the battery will not function well in this case. When alternators or motors ...


8

Yes, this is possible. Several companies (VAG, BMW) have switched to AC units that are driven by electric motors. For BMW, this is part of their Efficient Dynamics strategy, where they'll switch the compressor on/off depending on engine load to optimize fuel consumption. When the weather's not too hot, you can run the compressor intermittently without the ...


8

That wire will have been the main power connection from the alternator to the battery it is used for powering the car and charging the battery while the engine is running. By forcing this onto the chassis you will have shorted out your battery and hopefully you have blown a fuse-able link. Needless to say, this was very dangerous to do. If a fuse-able link ...


7

You should not incur any issues using a secondary battery with a battery isolator. It will not cause any damage to your alternator. For your edification, it won't be using wasted energy, but your engine will probably using a tad more gas to operate the alternator, which will have to do more work. On a side note, you might want to rethink exactly what you ...


7

No. Your 12V socket is designed to deliver 12V, at a current described in your car manual. Most of my 12V sockets in the car can deliver up to 5A apparently (haven't tested this though, but I run a 200W invertor when I go car-camping. It is handy for everything) The worst that can happen is if your invertor tries to draw more than the 12V socket is fused ...


7

Noise from an alternator can be early symptoms of it going bad. It's generally the bearing inside the alternator. You have a couple. With most modern vehicles the alternator bearings are located on the outside shaft and one for the rotor inside the alternator. When the shaft bearing starts to breakdown you'll notice a squealing noise or screeching when the ...


7

The voltage being a little low (13.75 is not low enough to be considered a problem in any case) is not going to affect their RPM reading - as it's the frequency of voltage variations that is measured to get your RPMs. I'd be tempted to say your tach is out slightly. You could ask them about that. There is a smartphone app that you can use to gauge RPMs - ...


7

The one tool you will need to purchase / borrow is a Volt Ohm Meter (sometimes called a Multimeter). Then you need to use it to read voltage AT THE BATTERY, before the car is started and after the car is started. My guess is you won't see any voltage difference. Before the car is started, I would guess you'd see voltages like 12.6v or so. After the car ...


7

To differentiate between the starter and the alternator you can check the battery voltage – should be about 12.6 with the engine off and 13.5-14.2 with the engine running if the alternator is doing its job. You may have a failing starter. You can get a good take on this by taking a current reading while trying to start. Usually this is done with a ...


7

I'm not going to tell you to try and utilize a battery charger to fix the issue as @MoveMoreCommentsLinkToTop has suggested in the comments, but it has been my experience when a battery has sat for an extended period of time with a constant power draw on it, the lead plates get sulfide crystallized over and will no longer take a charge. If it does take a ...


7

The alternator's drag on the engine varies with the electrical load on the alternator. So, yes, as you increase the electrical load, the alternator consumes more power from the engine, and the fuel economy drops. Except for the cooler, your hypothetical load is pretty small, so you might not notice the loss of fuel economy, but it will be there. You'll ...


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