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Ammeter on a really HOT day

Darthomas

Darthomas

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With all the recent discussion about voltage regulators and my own tuning of my mechanical regulator, I was intrigued by how I had been driving all day, and after getting stuck in slow traffic, when the temp gauge was "up", the ammeter went into the discharge zone, even with no lights, etc, ignition only.
I had wondered why the VR even HAD a discharge contact, now I know.
When the battery is baking hot, the increased temp raises the battery voltage, and the VR responds by making contact on the lower contact, thus not charging during this time. As soon as the traffic cleared, the temp gauge went back to the left end of "normal", and the battery cooled, the ammeter returned to center or only slight maintenance charging as we normally see. It's great to see proper engineering working the way it's supposed to.
Now I wonder if electronic voltage regulators are that smart, I don't think I've ever witnessed this in a car with an electronic regulator.
Anyone know if they can bleed off voltage to prevent battery damage this way?
 
Disconnect it before the car burns to the ground. Don't need it.
 
Ammeter, ampmeter, whatever it is called. If it doesn't start, it wasn't charging.
 
Sorry, but I am not having ANY problems or issues, I am an electronics engineer.
I was hoping someone else had noted this "feature" designed to keep from boiling away battery electrolyte.
I will never deprive myself of the valuable information the ammeter provides, no matter how many people choose to.
I visited the "Mad" webpage over 5 years ago, and became actually angry that some company wants to turn Chrysler Engineering into GM lowest common denominator disregard for what's going on, and sell people on the idea that less information is better.
I have no use for a voltmeter in my dash, when I am concerned with current flow and direction.
I have repaired and adjusted many a brand new mechanical voltage regulator that were poorly gapped and adjusted, on my cars and others'.
The ammeter is my friend.
Yes, I've seen cars toasted and in the junkyard from loose ammeter nuts.
Ain't skeered.
I was simply noting that I had never seen clearly the reason WHY a voltage regulator even had a "discharge" contact, now I see its usefulness in extreme heat.
And I wonder whether electronic VRs have the ability slightly discharge a battery when the voltage climbs too high due to underhood temps.
 
Darthomas said:
Sorry, but I am not having ANY problems or issues, I am an electronics engineer.
I was hoping someone else had noted this "feature" designed to keep from boiling away battery electrolyte.
I will never deprive myself of the valuable information the ammeter provides, no matter how many people choose to.
I visited the "Mad" webpage over 5 years ago, and became actually angry that some company wants to turn Chrysler Engineering into GM lowest common denominator disregard for what's going on, and sell people on the idea that less information is better.
I have no use for a voltmeter in my dash, when I am concerned with current flow and direction.
I have repaired and adjusted many a brand new mechanical voltage regulator that were poorly gapped and adjusted, on my cars and others'.
The ammeter is my friend.
Yes, I've seen cars toasted and in the junkyard from loose ammeter nuts.
Ain't skeered.
I was simply noting that I had never seen clearly the reason WHY a voltage regulator even had a "discharge" contact, now I see its usefulness in extreme heat.
And I wonder whether electronic VRs have the ability slightly discharge a battery when the voltage climbs too high due to underhood temps.
Click to expand...
So good to he here among the brave engineers. Still, I recommend a battery cut-off switch and the carry of 2 extinguishers. Grab the Halon first so powder residue won't be found for the next 5 years.
 
I guess I'm skeered then. My first Bee burnt up cause of this 30 yrs ago, so if there is a preventive measure, I'll take it!
 
I have always carried a fire extinguisher,
and I have regularly polished the ring terminals on the back of the ammeter,
checked to see that they haven't loosened, and checked them to see if they have gotten warm during use.
I also like seeing high charging current the moment after starting the engine, then watching to see the charge rate taper off within a minute or so.
I like leaving something like the parking lights on for half an hour, then seeing a medium charging rate and watching the charge rate taper off over a half hour of driving.
Like a passenger side rear view mirror, it's something I could live without, but I appreciate the information too much to ever think about eliminating it, then wonder what's going on.
 
I still have my ammeter and it's staying, this whole car burning thing is blown way out of proportion. Very rare and usually due to poor maintenance of electrical system (corroded connections) , no fusable link, or overpowered alternator and excessive load on the system.
 
Without an ammeter, how can you easily just bump the starter and know you've stopped the motor at a position where the points are open?
Add a lamp in parallel with the coil?
What?
How would you know when current leakage exists beyond instrument cluster usage, field on the alternator, etc?
 
440+6 said:
I still have my ammeter and it's staying, this whole car burning thing is blown way out of proportion. Very rare and usually due to poor maintenance of electrical system (corroded connections) , no fusable link, or overpowered alternator and excessive load on the system.
Click to expand...
People don't actually drive cars without a fusible link, do they?
You must be kidding.
 
Darthomas said:
People don't actually drive cars without a fusible link, do they?
You must be kidding.
Click to expand...
Only takes one fire to become a believer. I will miss out on the pleasure of watching the needle I guess.
 
I guess I worked on Jaguars for to long... No more tempting fate.. I can read a Voltmeter like a Ammeter, will install a digital readout of battery voltage in the center console for accuracy..
You remind me of my Father, a Physics Teacher that doesn't wear a seatbelt..
 
Dennis H said:
Only takes one fire to become a believer. I will miss out on the pleasure of watching the needle I guess.
Click to expand...
The fusible link is a very wise design feature, whether the ammeter stays or goes.
And it's not about "pleasure", watching the needle.
 
So is the question ,does heat effect the output of voltage reg. /Ampmeter . From my memory as the Mechanical reg coils warms up their will be more voltage, until it normilizes so if the engine compartment temperature is high this could effect the pull of the magnetic field.


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Well to answer your original question about electrical voltage regulators, I guess you have to ask another electrical engineer.
 
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