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22 votes

Alternator dying so junk car?

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 ...
PeteCon's user avatar
  • 8,712
21 votes
Accepted

I charged my car battery with no water in it

The battery is toast. Save yourself potential serious injury. Buy a new one. If the battery has been dead for eight months...it is pretty much a goner.
Old_Fossil's user avatar
  • 3,962
19 votes
Accepted

Why can't alternators provide full current at idle?

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 ...
vini_i's user avatar
  • 16k
8 votes
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Will never charging the batteries of a hybrid electric plug-in vehicle damage it?

No, it won't get damaged. But you also shouldn't let the battery totally empty for long periods. Li-ion batteries are best stored with some charge (normally about 40% is recommended charge level for ...
Evren Yurtesen's user avatar
8 votes

Battery or what?

There are several possibilities: The bike's battery is bad. This is by far the least likely cause, as the previous battery behaved exactly the same way. The chances of having two batteries fail ...
DavidRecallsMonica's user avatar
7 votes

one wire alternator

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 ...
zipzit's user avatar
  • 6,569
7 votes
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Connecting to the Battery During Emissions Testing to Measure RPMs?

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 ...
Rory Alsop's user avatar
  • 18.6k
7 votes

Alternator dying so junk car?

I have seen somebody spot-weld a short bolt to the rounded nut they are having trouble removing. It's cheap and quick if the equipment is on hand.
Les Ferguson's user avatar
7 votes

Alternator squeal

That year of RAV 4 uses the alternator to tighten the belt. It may not be adjusted properly and the belt is slipping. . .
Moab's user avatar
  • 7,990
6 votes
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Car Battery Flat After Sitting for 9 months - BMW e87

Yes, a standard trickle charger will be fine. You need to make sure you give it plenty of time on charge, circa 16 hours; cranking a diesel engine takes around 700 Cold Cranking Amps. You may also ...
Steve Matthews's user avatar
6 votes

Car Battery Flat After Sitting for 9 months - BMW e87

A lead acid battery will self discharge about 5% every month. Assuming your battery was 100% charged, and there is no parasitic draw, that gives us a charge of ~55% after 9 months. Realistically, ...
Nick's user avatar
  • 1,945
6 votes

Why can't alternators provide full current at idle?

If an alternator could provide its full output capacity at idle, what would it output at red line? Output amperage is proportional to rotational speed of the alternator. Via gearing, an alternator ...
justinm410's user avatar
  • 1,742
6 votes

Will never charging the batteries of a hybrid electric plug-in vehicle damage it?

The car will charge its battery while driving, e.g. when you brake. This allows the electric motor to augment the diesel engine, reducing overall fuel usage. The result is that the charge state of the ...
Hobbes's user avatar
  • 4,412
6 votes

Alternator squeal

More than likely the problem is either your serpentine belt is worn out, or the tensioner pulley isn't providing enough tension to keep the belt in place. Belt slippage accounts for the low amount of ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
5 votes

Charging Battery

Charging a dead battery using the alternator is hard on the alternator, it is best to use a Battery charger. Alternator manufacturers know the same things about alternators that we do- they are ...
Moab's user avatar
  • 7,990
5 votes
Accepted

Cigarette lighter socket no longer charges phone

You could have voltage at the socket with only one strand of copper connected so simply testing for voltage doesn't mean there isn't a fault. How to check for a bad Ground: Connect a load to the ...
Newbie Noob's user avatar
  • 2,781
5 votes

Battery only charges with parallel load - why? recoverable, or replace?

Given how complicated this seems from both posts, I would suggest that you fit a known good battery and run the complete set of tests on the charging system. I would include the tests for voltage ...
Solar Mike's user avatar
  • 34.6k
4 votes

Why can't alternators provide full current at idle?

Your premise is backwards. Max output and sufficient output aren't the same thing. Your own numbers show that alternators provide sufficient output to keep the battery fully charged at idle. If they ...
tlhIngan's user avatar
  • 12.2k
4 votes
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Motorcycle Lithium Battery - Potential Parasitic Drain

Just like with a car. Remove the negative battery cable. Get your multimeter, set it to DCA (DC Amps). Use 10A mode if its available. Connect it between the negative post and the cable. Reading ...
rpmerf's user avatar
  • 8,403
4 votes

unique alternator issue

My first thought is your ground wire to the trailer is not large enough causing a voltage drop to the rear battery. However after some research turns out your alternator is controlled by the PCM and ...
Move More Comments Link To Top's user avatar
4 votes

Cigarette lighter socket no longer charges phone

You could perform a voltage drop test. If the voltage is reduced by the time it hits the phone, it might be high enough to trigger the charging indicator, but not actually be able to charge. ...
Mobius's user avatar
  • 1,318
4 votes

Why is my car not charging?

Check the oil level!! Most important; do not run the engine until you replace the oil and get a new oil cap. The oil warning light is there to let you know of a dangerous condition; there is not ...
CharlieRB's user avatar
  • 9,015
4 votes

Bad ground cause alternator to output low volts?

Run the engine at 2k RPM. Turn on all the loads (blower on high, headlights on, rear defrost on, and so forth). Measure the voltage across the battery and the big bat alternator terminal to ...
vini_i's user avatar
  • 16k
4 votes

Can I trickle charge battery through OBD2 port 2007 civic

The 12v pin on the OBDII should be constant on regardless of the key position. Here is the pin out: You can test it with a multimeter to ensure it is this way in your vehicle. Whether it will work ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes
Accepted

Charging car battery with charger without disconnecting from car

If you are using your charger on "float mode", you shouldn't have a problem leaving your vehicle battery charging indefinitely. The purpose of the float mode is not to charge the battery, ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
3 votes

I charged my car battery with no water in it

The "strong smell, like sulfuric acid" is in fact sulfuric acid, which is the acid component in a lead-acid battery. If it's coming out strongly enough for you to smell, the battery is dangerous. ...
Mason Wheeler's user avatar
3 votes

Can a conventional car be used to charge an electric car?

Old post but I want to leave my experience since I did this in real life. I have a fiat 500e (well, my wife does). Same, some day she was so close to run out of battery. Nowadays there is an app ...
DefToneR's user avatar
  • 131
3 votes

Jumping car with too many amps?

Think of electricity as water, where voltage is the pressure that exists due to height of the water column above the point where you are taking it (known as "head" in fluid dynamics), and current is ...
davea0511's user avatar
  • 131
3 votes

Is any power from the alternator 'free'?

No, it's not free. It's just that compared to everything else going on in the car, the power to charge your phone is insignificant. You could ask a similar question: "where does the power come from to ...
Anthony X's user avatar
  • 872
3 votes

Cigarette lighter socket no longer charges phone

Just because you are getting voltage does not mean you are getting current. You may have a frayed connection or corrosion somewhere between the car battery and the cigarette lighter that reduces the ...
tlhIngan's user avatar
  • 12.2k

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