Toyota Nation Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
29 Posts
Discussion Starter #1
I get confused when it comes to how the electrical and starting systems on cars work and yesterday when my car broke down was no exception. I did do a search here before making my post and the information I found confuses me more than ever so I am hoping for some clarification.

I have a 2001 Camry CE with the 2.2 Ltr 5S-FE engine. The former battery in the car was at least 2 1/2 years old when I bought the car and gave me good service. Yesterday after doing some shopping I tried to start my car and nothing. No starter clicking, no horn, nothing. I had a feeling it was the battery and I was able to jump start the car hoping to make it back to my Condo and my tools. About halfway back to my Condo the car just died and I barely made it off the road onto a service lane. I called my neighbor hoping he would get my tool box and bring it to me so I could replace battery onsight but all he wanted to do was argue so I blew that idea off. I had to call a tow truck to get my car back to the Condo where I did replace the battery and from what the car did to me when it broke down I thought sure the alternator was gone as well but possibly not.

When I put the new battery in I cleaned the terminals and after I started the car I used a volt metre to test the voltage the battery was getting. At idle with no load it is getting 14.3 volts and when I turn on the AC and headlights it is still getting 14.3 volts so at least for now I think (and hope) I am good but this is where my extreme confusion comes in. I had always thought that the alternator ran the car and the battery was just for starting? This is why I tried to make it back to my Condo yesterday because I was under the impression that the alternator powered the car but maybe not. My car is running and OK for now but could someone please explain to me the relationship between the alternator and the battery and what they do for the car? This is driving me absolutely nuts.

Thanks.
 

·
Moderator
Joined
·
4,031 Posts
If the alternator is bad, a new battery will keep the engine running until the battery power is depleted. I think you have a faulty alternator. Just because it's pumping out volts, doesn't mean it's pumping out amperage. My advice is to have the alternator tested. Most major auto parts stores will do this for free. They can test it with the alternator still in the engine while it's running, however I prefer to remove the alternator and have them bench test it. That's just me, though, and if you want you can just drive it there and have them test it.
 

·
'00 4 Cyl. Auto Camry LE
Joined
·
795 Posts
I'll try to help.

"All things electrical, start at the battery." The battery provides initial starting, and supplies power to the various electrical systems in the vehicle to keep it in operation while running.

The battery itself consists of multiple individual cells inside, connected in series, to provide the voltage / amperage needed sized to the electrical requirements of the vehicle.

If one of those cells is compromised, it will affect vehicle operation. Typically referred to as a "bad cell" in the Battery.

The typical lead-acid automotive battery is filled with electrolyte, a mixture of acid and Distilled water, which reacts with the plates in each battery cell and provides -> the electrical current within the Battery. If the level of the electrolyte is low inside the Battery, it will affect the holding capacity of Battery - in turn affecting vehicle operation.

--

The Battery, in itself, cannot sustain continuous operation of the vehicle, while the vehicle is running - the electrical load demands of the vehicle would drain the Battery quickly.

A charging system is needed, to continuously recharge the Battery, while in operation.

The charging system typically consists of an Alternator ( commonly referred to as a Generator ), connected to the Battery through a high amperage fuse, in the main engine compartment fuse box.

While the vehicle is running, the Alternator generates A/C electrical current, which is passed through a Diode Rectifier bridge circuit, to convert the raw A/C current generated, to vehicle compatible DC voltage.

A voltage Regulator circuit inside the Alternator further limits that current / voltage, which is output from the Alternator -> to the Battery.

--

A typical automotive lead-acid Battery must be able to handle electrical demands, while the vehicle is not running / in operation. It also must be able to start the vehicle in adverse conditions which may affect the voltage / current output of the Battery, e.g.: cold winter weather.

The measurement of the ability of the Battery to start the vehicle in cold weather conditions is referred to as the Cold Cranking Amps, or CCA capacity of the battery.

The battery must also be able to handle some measure of electrical system demands while the vehicle is not running / in operation. Electric radiator cooling fans, lighting, alarm system, keyless entry, etc. all need power to operate.

The measurement of the ability of the Battery to provide power to various electrical systems, while not running, is referred to as the Reserve Capacity of the battery.

--
With the above said ..

Typical Battery Voltage, measured at the Battery posts, is 12.2 - 13.6 volts, depending on Battery condition, age, and capacity.

Typical Charging Voltage, measured at the Battery Terminals/Posts, while the vehicle is running, is 13.9 - 14.6 volts, again depending on Battery age/condition, -and- electrical load of the vehicle @ time of measurement.

--

These ranges are -general indicators- of the condition of the Battery, and charging system health. They do not measure current output of the Alternator, or show the current holding capacity of the Battery though.

If any doubt / concern as to the condition of the Battery or Alternator / charging system, recommend taking the Battery and/or Alternator in to have a more comprehensive Battery or Alternator load test done.

Most national chain Auto Part stores have the testing equipment, and will test for free / or a few dollars, depending on whether or not you purchase from them. *Tip: call the store, and confirm they have the equipment / connectors needed to test -your- Battery / Alternator, before heading over.

--

To summarize / answer your questions above:

The Battery powers the vehicle electrical systems. "All things electrical, start at the Battery."
The Battery is the electrical storage container responsible for supplying power to the vehicle.

The Alternator / charging system -keeps- the Battery charged, while the vehicle is in operation. * If it didn't, the battery would drain / and die quickly.

The charging system is responsible for maintaining charge/current in the Battery: it is an equally important part of the vehicle's electrical system.

Hope the info helps.
 

·
Registered
Joined
·
2,460 Posts
CamryFL provided some very useful information. But let me summarize.

Most likely, your battery suffered from sudden failure due to physical internal damage that compromised the chemical separation of cells. This is a common problem, especially in the summer time. The battery case is made of plastic (including cell dividers) and when the battery gets hot (due to engine heat or ambient temperatures), coupled with vibrations, bumps in the road, etc, the plastic gets weaker and physical failure can occur.

The other type of battery problem is a slow degradation of the battery's ability to hold a charge, which happens when a battery is discharged too often or is just too old.

When a battery suffers sudden failure due to cells being compromised, sometimes it can work for if jump-started and the alternator supplies enough voltage to run the car, but the battery (in addition to acting as starter) also acts as a "buffer" to make sure the voltage is continuous. In all your electrical appliances and gadgets, they use capacitors to provide the same function by buffering the power if a short term power drop-out occurs (which occurs more often than you realize).

So everything you describe seems to be consistent with a dead battery (due to internal physical failure) and a good alternator. Obviously, there is no way I can be 100% sure if that is true in your particular case.
 

·
500,000 + Miles
Joined
·
411 Posts
I gotta add my two-cents here. I think you have been given some really good details but sometimes too many details muddies the waters.

Your car sounds like is about to the age where it will have racked up some miles. You didn't say how many miles you have but I think our alternators begin to fail at around 200,000 - 300,000 miles.

1. First, your car usually has both a working alternator and a working battery but it can run for a little while on just your battery if the alternator is dead. Your car can also run (but won't start of course) for hours on just your alternator and no battery at all.

2. If your alternator quits, you should see the battery symbol light up on your instrument panel to show you have a charging problem. I don't think that light will come on if your alternator is working....even if you disconnect and remove your battery while the car is running.

3. Your car can run with the battery removed from the car because the alternator is providing current for the ignition system, i.e., the coils and such that are needed to provide a spark for your plugs. Newer cars have all sorts of other essential electrical needs for computer junk.

4. If your alternator light should ever come on while you are driving, be sure to turn off any non-essential electrical devices, such as climate control, radio, headlights, turn signals, hazard lights, etc., so as to preserve the electrical supply in your battery for your engine's needs. It very much depends on the age and condition of your battery but you can drive maybe 15-30 miles with a dead alternator. I had a VW Rabbit diesel that went further than that one time because about the only electrical need an old ("old" being a key word) diesel needed was to keep the fuel cutoff valve open.

5. Last point is that if your alternator light does come on, indicating your alternator is no longer putting out power, you can sometimes cripple in by pulling over as soon as the alternator light comes on, leave the car running of course, pop the hood, and carefully give a few good raps with a hammer (or other suitable substitute you have with you) on the metal housing of your alternator. THIS CAN BE VERY DANGEROUS IF YOU CONTACT THE SPINNING PARTS OF THE ALTERNATOR/BELT! Tapping on the alternator in this way can cause worn parts inside the alternator (the brushes) jiggle back in contact with the armature and thus keep generating electricity for a little longer...perhaps a couple hundred miles so you can get back home. There are some other electrical parts that may go out that will not respond to this trick but, if it works, your alternator light will go off for at least a little while.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #8
Hi Everyone, thanks so much for all of your information, advice, and tips. I was able to get my car to Advance Auto to have the alternator looked at and everything is fine. The salesguy gave me a copy of the printout so I feel better. The battery I took out of the car was a Duracell car battery (yes, you read that right, Duracell) and it was in the car when I bought it. There was no date sticker of any kind on the battery so I have no idea when it was made or how long it had been in the car but I know I got 2 1/2 years out of it.

Last night When the car died I replaced it with an EverStart Maxx battery from Walmart. It was the least expensive I could find and I do not have a lot of money. I know several people who have this battery in their car and who say good things about the battery. The battery I got has a 5 year guarantee and I know Walmart is not tight in the way they treat their customers so I feel reasonably OK. When I was walking out with the salesguy to have him test my alternator there was a customer bringing in a Walmart battery as a core and I got a look at the date sticker on the battery and it said 5/14. If I get that kind of live from the battery I just bought I will be singing Walmart's praises from the housetops.

Thanks again for all the great responses and definitely thanks to everyone staying on topic and not de-railing this post. Have a good day everyone.
 

·
Registered
Joined
·
2,460 Posts
The battery I took out of the car was a Duracell car battery (yes, you read that right, Duracell) and it was in the car when I bought it.
Duracell is a brand, not a manufacturer of auto batteries. Almost all auto batteries sold in North America are made by Johnson Controls, East Penn, or Exide.

I believe that the Walmart Everstart MAXX is made by Johnson Controls. Not sure who makes the Duracell auto battery.
 

·
Registered
Joined
·
480 Posts
It depends on your location as to who will be the maker of the Walmart batteries. (Since batteries are very heavy Walmart may be sourcing the batteries from a nearby plant.) It used to be JC In my area of the SW, but now all of the batteries are made by Exide.
I was in Alabama last month and noted many of the same group size batteries that are made by Exide in my market where still being made by JC there.
 

·
Registered
Joined
·
2,460 Posts
It depends on your location as to who will be the maker of the Walmart batteries. (Since batteries are very heavy Walmart may be sourcing the batteries from a nearby plant.) It used to be JC In my area of the SW, but now all of the batteries are made by Exide.
I was in Alabama last month and noted many of the same group size batteries that are made by Exide in my market where still being made by JC there.
A lot of companies, including Toyota, like to do business with two suppliers for a given part, so they can squeeze them against each other. Plus it mitigates risk if one supplier has problems such as a labor strike or something.
 

·
Moderator
Joined
·
4,031 Posts
Glad to hear your alternator is OK, and hopefully it was just the battery. Let us know how things are going over the next few weeks.
 
1 - 12 of 12 Posts
Top