Can using a dashcam in parking mode kill your alternator?

Nigel

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Just wondering what people's experience is with dead alternators, how long do they last with and without parking mode in use?

My alternator failed a few days ago, first time ever, so I did a bit of reading, don't believe most of what is written, but some things do make some sense, such as:
Most alternators are designed to produce the maximum rated power for only short periods. The system design is for the alternator to charge the battery for less than five minutes and then drop to a charge rate of less than 10% of its maximum rated power.
A battery with a short in it, (or a half empty battery caused by dashcam parking mode use) 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, tapering back as the current used to start the vehicle is replenished. Constant running at full output simply overheats them and the rectifiers fail, the insulation on the rotor windings can be damaged, the grease in the bearings can be overheated, etc.
Using an additional battery such as the Cellink Neo is not going to help much with this due to the high charge rate of these batteries, in fact the initial load on the alternator may be higher since the alternator is having to charge two batteries flat out!

If running parking mode results in alternators lasting for minimal instead of maximal time then parking mode could work out expensive:
Generally speaking, you can expect your car alternator to last anywhere between 40,000 and 100,000 miles.
...
The total repair cost for an alternator bought at an aftermarket is $400 to $800, having a labor cost of $50 to $120 per hour. – If it is an OEM part repaired at a car dealership, then the total repair cost is around $500 to $1,800 with the same labor cost.
Not sure why repair costs should be that expensive, I fixed my 14 year old alternator before reading any of the guides, diagnosed it as worn brushes (which none of the alternator fault diagnosis guides seem to mention as a possibility!), it cost me £18 for a new pair of brushes, 6 screws to remove the cables and cover, replace the brushes, put it back together, and it is working perfectly again :happy:
 

kamkar1

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I have yet to have that happen to me, and its only after 2006 i have been buying brand new cars.
The Opel i drove in the start of the 90ties saw a pretty severe load i assume on the alternator due to the car being crammed with car hifi, cranking it up and not having the car running i think it would have emptied the 2 batteries pretty fast.
3 X 500 watt + one 4 X 120 watts amplifier.
 

rzvmad

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A dash cam will not shorten the life of the alternator, but a poorly maintain battery will. Driving short and often trips does not give enough time for the alternator to charge the battery properly. In this case is best to charge the battery once a week with a smart battery charger. It is also recommended to change the battery every 3 to 4(for premium) years as most battery will start failing at this point and put a bigger stress on the alternator. Life of the battery is also impacted by the climate. Hot summers and cold winters will shorten the life spam.
Other cars have a "smart charge" option meaning that the alternator will charge only if the battery needs to be charged. That is a different story but still a poorly maintain battery will stress the alternator shorting its life spam.
Old alternators are "easy" to fix, just change the brushes but new ones require a bit more like bearings and brush ring. On an "by the book" repair this need to be changed.
 

WeedeaterDM

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Just chatted with a WAI Global engineer, here is his response. If the draw vs AH rating results in a drop in the battery capacity to around 80-ish percent, and it is then driven for 20+ minutes at highway RPM, then it's basically a non-issue.... However if the load drops the battery below 80% and / or it's puttered around in town, the system won't recover and / or the alternator will be 'overloaded'."
 
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Nigel

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Just chatted with a WAI Global engineer, here is his response. If the draw vs AH rating results in a drop in the battery capacity to around 80-ish percent, and it is then driven for 20+ minutes at highway RPM, then it's basically a non-issue.... However if the load drops the battery below 80% and / or it's puttered around in town, the system won't recover and / or the alternator will be 'overloaded'."
So parking mode with a voltage cutoff at 12.2 volts (50% full) is sure to result in "the alternator will be 'overloaded'." whenever the cutoff operates.

So the question then is, what is the result of overloading your alternator daily due to the use of parking mode, it's fairly obvious that the alternator doesn't explode the first time you do it...

Old alternators are "easy" to fix, just change the brushes but new ones require a bit more like bearings and brush ring. On an "by the book" repair this need to be changed.
I don't understand why bearings and rings on newer alternators should fail any more than on older ones, the alternators still work the same way. But I also don't understand why all the guides to alternator issues only suggest that you replace the faulty alternator with a new or reconditioned one instead of just changing the brushes/regulator. Maybe they are written for the purposes of making lots of money for the parts business.
 

kamkar1

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I was of the understanding a car would charge full speed as soon as it got the chance, but it have always wondered me how charging are handled and how it is lowered as it near full charge.
Maybe in normal use the car will never charge full speed, and so just trickle charge in normal use,,,,, but then how about modern stop/start cars, if you drive in a town traffic maybe a bot congested i could see a car needing to be cranked a lot more than in a normal situation.
But if a alternator in a modern car put out 50 - 100 AMPS, then you do get a fast charge if it jump strait to full power charging, and so the few 100 amps you use for a split second to start the car would be replenished pretty darn fast.
I am just wondering cuz i have never seen a charge controller in a car, and thinking about that now confuse me a little.
Maybe that stuff are all in the alternator ?
 

jeez123

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The charge controller you were looking for is called a Current regulator, and is the thing that prevents the alternator from running 100% capacity all the time, during running engine.

Found this danish article about the thing >> https://viaretro.dk/2015/09/laderelae-saadan-virker-det/
 
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Nigel

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I was of the understanding a car would charge full speed as soon as it got the chance, but it have always wondered me how charging are handled and how it is lowered as it near full charge.
Maybe in normal use the car will never charge full speed, and so just trickle charge in normal use,,,,, but then how about modern stop/start cars, if you drive in a town traffic maybe a bot congested i could see a car needing to be cranked a lot more than in a normal situation.
But if a alternator in a modern car put out 50 - 100 AMPS, then you do get a fast charge if it jump strait to full power charging, and so the few 100 amps you use for a split second to start the car would be replenished pretty darn fast.
I am just wondering cuz i have never seen a charge controller in a car, and thinking about that now confuse me a little.
Maybe that stuff are all in the alternator ?
Yes, the charge controller is in the alternator. The alternator has no magnets, instead the rotor has coils which work as an electromagnet and there is a voltage regulator which controls the amount of current flowing through the rotor coils and so controls the amount of magnetism so that the correct voltage is generated in the stationary coils on the outside of the alternator. So it will always try to keep the voltage at around 14 volts, however there is a limit to the amount of current it can put into the rotor coils so there is a maximum current that can be generated, thus my battery should be charged at 80 amps until it reaches 14 volts, after that the charge current will start to drop until it reaches 0 when the battery is full. Normally it reaches 14 volts almost immediately, I guess that it needs to be less than 50% full to not reach 14 volts when 80 amps is flowing into it.

Starting the car engine requires very little power, a little 20,000mAh powerbank can start an engine about 100 times if it the LiFePo4 type that can produce enough amps for the 1 second required. It does need a lot of amps, but for a very short amount of time, so not much power overall.
 

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New cars have a tremendous amount of computers and sensors that use a lot of power. Anything that uses power will reduce the life of an alternator. The question is how much life it can take.
 

rzvmad

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Bearings and slip rings fail on the new ones because "they don't build them like they used to". Bosh used to build good alternators, now they are design to fail after a good number of km. 250k to 300k. Yes, alternators work the same way, but try to change the brushes on a old one and then try to open a new one and you will see that is required special tools just to put the brushes in.
You will not be able to buy a "new" alternator if the old one is broken. That is because they will not build a new one for an old car, instead you will be able to buy a refurbished one. As a notice the old alternator is used as a core meaning that you will get some money back. The old unit is send out for refurbishing after that is waiting for the new customer.
 

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Bearings and slip rings fail on the new ones because "they don't build them like they used to".
This is a large part of the equation; nobody builds a vehicle today expecting for it to still be in daily service ten years hence. They know that by then the original owner has dumped it so why should the manufacturer care? :mad: The under-hood environment in hotter today than ever before which doesn't help the alternator's lifespan. That and attempts at weight-saving makes for a bad base to start from. And the same goes for car batteries being just enough for the job and no more. But enough ranting.

It is true that car alternators are not designed for continuous full output and that this will have an adverse effect on them. The real question is "how much is excessive?" and to that I feel that if the battery is good, the effects will not be large for the alternator unless you try to stretch the battery's life as far as possible, which most of us do since it's only when the car doesn't start that we replace the battery, which by then is totally shot and not just worn. As a lead-acid battery ages in use, it builds up an increasing resistance to being charged and this is the real culprit here, becuase that makes the alternator work harder to bring it up to a fully-charged level each time. And car starting batteries don't like long low-current draws line dashcams while parked- that accelerates the increasing resistance to charging. It's a "perfect storm" for the entire charging system.

There's no free lunch with anything. If you use your cam when the car isn't running you pay in shorter battery life and shorter alternator life. With the battery I think you'll see between 5% and 20% shorter service life based on which cam and how it's used. It would seem the alternator's service life would follow that. We all know to use premium batteries when we use dashcams while parked- they are not a great expense compared to cheap batteries. But there are no premium alternators to be had since the computers which run toady's cars aren't designed for anything other than the one the car is built with. The bet you can do is to acquire an entirely new alternator from the dealership (expensive!) as almost everything else will be rebuilt which will wear out sooner. But rebuilt is often good enough, especially if you do the install yourself since with many cars the labor charge is higher than the part cost when you have someone else do the job.

So in conclusion I don't think alternator life is a significant factor nor dashcam use, provided that you don't wait till the very end to replace the car battery. And given that most car alternators should last 7+ years, only those driving older cars or ones known for short alternator life might be concerned about this. For the "DIY" types among us I recommend joining a specialty forum for your car to learn it's quirks and possible solutions to known issues, and also looking for repair vids on YouTube which will give you an idea of whether you want to DIY or not.

Phil
 

kamkar1

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Planned obsolescence are indeed a travesty, so are a lot of other things today.
Got a program on TV running about the kids medicine industry, apparently parents just cram pills down the throat of their kids, i cant recall getting a single pill when i was a kid and sick.
Actually when i was sick, the best part was the orange juice which i did not get when i was well, as well as comics to read in bed.
Actually i think i was way past 10 before i got my first pill for anything.
There is a story that in the old days Mercedes cars was so good, that they had to make them worse as people just got that one car, and as it rusted slowly and pretty much had no mechanical problems people just kept pushing back the purchase of a new car.
And IMO that's the way it should be, cuz i see Planned obsolescence as a severe load on the environment, and in a ideal world you just had to buy 1 car, and ideal is what we should strive for and reward.
 
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Interesting, I just assumed alternators could handle constant use just fine.

Maybe AGM batteries would help because they have lower resistance and charge quicker. With some cars you can also use a bigger alternator
 

crabu2

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You guys are too worried over this. Based on my experience, alternators rarely fail. The last time I had one fail was on a 1993 Nissan Sentra. Before that it was on my '95 Jeep and a '87 Mustang. The Sentra had around 90K miles on it, the Jeep had 150K miles on it when it failed. The Mustang had around 190K miles on it. To be honest, I'm a bit surprised the Jeep's alternator didn't fail sooner or since because it's got some hard miles on it from offroading. Lots of river crossings and I've had mud cakes throughout the engine bay.

My current daily driver is a 2007 Camry, it's got 290K miles on it. Alternator is still fine. I had a 2004 Dodge Ram (cummins) and that had over 500K miles on it and never needed an alternator.

It's a crap shoot.. You don't know what's going to cause it to one day die.
 
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Nigel

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You guys are too worried over this. Based on my experience, alternators rarely fail...
That seems to be most people's experience, but then you go on to list 3 failures and the internet guides to alternator failures seem sure that you should only expect between 40,000 and 100,000 miles from one!

The point of the thread was to find out if there is actually a problem, and given the lack of response of actual experience of failures, it seems that there is no problem, so no, we are not too worried!
 

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Lead acid batteries do not accept current very well compared to lithium batteries. A low battery could take around 50A for a few minutes then the charge rate drops quite a lot, if this overloads the alternator then they must be crap to begin with. My camper van has a 90A alternator in it, the manufacturer also offer 150A and 180A alternators. Running all the engine systems, lights, accessories could take around 40A. If you have the ability to monitor the voltage while driving you can tell if the alternator is overloaded or not. My voltage is normally 14.3V, now if there is more load on the alternator than it can handle that voltage will be lower as the voltage regulator in the alternator is putting the maximum current into the coils but it cant reach the voltage. This generally happens within a few seconds but longer if the battery is discharged.
 

country_hick

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I thought the new cars could use 100 amps or more based on all of the electrical needs of the sensors, computers, and everything else cars did not have in 1950.
 

scote

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Its possible. Diesels use less. No spark plugs. 40A was what i read was typical for my vw t5 van.
 

rzvmad

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If you are referring to old diesels than yes. A lot of new diesel engines have piezo injectors meaning that it requires a lot of volts and amps to activate the injectors. My 2006 Renault Clio has a 1.5 diesel engine with 68 bhp and the alternators maximum output is 100 amps. I think the petrol variant has around 70 to 90 amps.
 
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