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 ...
  • 8,602
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.
  • 3,862
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 ...
  • 15.9k
12 votes
Accepted

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

No, you cannot. Well, you might be able to, but not in a feasible way in any likely manner. Electric Vehicles commonly have two separate electric circuits. One running at the normal 12V, which ties to ...
  • 464
11 votes

Jumping car with too many amps?

The starter circuit should only draw whatever current it needs so the excess shouldn't cause any problem.
10 votes
Accepted

Can I safely upgrade to an AGM battery?

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 ...
10 votes
Accepted

Jumping car with too many amps?

Those numbers are the max that they can supply. Your starter will "automatically" use as much as it needs up to the max. If the starter needs more than those units can supply, the jumper will only ...
9 votes

Jumping car with too many amps?

The amp count tells you the maximum amount of current that the equipment can supply. Eg. Your car needs 600 amps to start: The 1000 amp jumper can handle it. Your car needs 1200 amps: The 1000 amp ...
  • 340
9 votes
Accepted

How can you optimise the rate at which your electronic devices will charge in the car (fast in-car charging)?

The charging system of a car can deliver TONS of power, so small fluctuations in the alternator or battery are going to be meaningless to the comparatively small amount of power a phone charger needs, ...
  • 13.2k
8 votes
Accepted

Is it possible to charge car battery through cigar lighter socket?

Yes, it is possible to charge the battery through a cigarette lighter socket, but there is a couple of caveats: The car's circuitry must have the lighter socket "live". It may require setting the ...
  • 589
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 ...
7 votes

Will an auxiliary battery hurt a vehicle's alternator?

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 ...
7 votes

Charging circuit

The fastest, cheapest and easiest solution is to add a battery disconnect switch to the car. After placing the ignition switch into acc mode the open the hood and disconnect the switch. When you ...
  • 15.9k
7 votes
Accepted

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 ...
  • 18.5k
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 ...
  • 6,529
7 votes
Accepted

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 ...
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.
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. . .
  • 7,960
6 votes
Accepted

Radio and Charging Outlet Stopped Working

They are typically on the same fuse. Charging outlet should be listed as a cigarette lighter.
  • 8,413
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 ...
  • 1,722
6 votes
Accepted

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 ...
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, ...
  • 1,965
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 ...
  • 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 ...
5 votes
Accepted

Will an auxiliary battery hurt a vehicle's alternator?

So I thought I'd come here to explain some physics. There are two important equations: p=iv - power (watts) = amps * volts v=ir - volts = amps * resistance Note - an amp is a measure of how many ...
  • 221
5 votes

Weird charging issue

The PCM controls charge rate on this vehicle. It monitors battery voltage and amperage flows to decide when to charge and when to rest. This is done as a fuel saving strategy. Some systems use a ...
  • 11.5k
5 votes

Motorcycle won't turn over immediately after a pit stop

You may have a bad stator As @paulster2 stated, you should have your battery tested. You could have a lead plate the broke free inside the batter and grounding out that cel to another cel. Your ...
  • 32.8k
5 votes

Can you charge an electric motorcycle at an electric car charging station?

2015 and newer Zero Motorcycles have a "Charge Tank" option that allows you to use standard chargers: Zero Motorcycles Charging Options. For fast charging on the go, Zero offers the Charge Tank ...
  • 13.2k
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 ...
  • 7,960
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 ...
  • 2,762

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