Problem With Power Outlet

But earlier, you suggested willy-nilly replacing the battery without
determining where the problem is (by intelligent voltage tests). Except
for a shorted cell condition (which is obviously not the case here), for
all practical purposes (i.e., all but extreme system loading), a weak
battery will not show up with the alternator pumping out over 14 volts
which the inverter should run with handily - BARRING VOLTAGE DROPS
ELSEWHERE IN THE SYSTEM. I'm not following your logic.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Not at all, you obviously have me confused with someone else. I DID suggest
that if the battery was showing 12.8v just after it had been charging that
perhaps it ws time to look at replacement. But then, that was an
"intelligent voltage test", I simply suggested that the outcome wasn't used
properly.

My logic is very simple, unlike the rest of the thread.....


1) Load test battery
2) determine nominal voltage (not "just been charging" voltage)
3) determine voltage at power port
4) act accordingly

Sorta like I posted the first GD time.

WTF is wrong with you people? its a SIMPLE problem.

--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

no, it was me that suggested that, rather than over-analyze the situation,
just stick another battery in and see what happens

even at 5 bucks an hour, the time spent on this so far, far exceeds what a
battery costs

 

Sure it will.

Matt

 

Then so what? If the battery will provide enough power to crank the
car, it will provide enough power to charge a laptop for more than a few
seconds. Two seconds of cranking the engine would likely charge the
laptop battery several times over. So what do you think a load test is
going to prove?

If the voltage is dropping this much with an 8A draw then it would drop
so much with 200+A for the starter than the engine wouldn't crank. Yes,
a bunch of you have suggested to replace the battery before doing any
real troubleshooting and a bunch of you are likely wrong.

This is funny. If you have an electrical problem in your house, do you
start troubleshooting at the power generating plant of your electrical
untility?

Anyone who suggests changing a battery before performing even the most
basic checks and reviewing a schematic needs further training.


Matt

 

There is no logic to parts replacers. Folks that use logic -
troubleshoot. Those without logic replace parts until they get lucky.

Matt

 

How does one take a voltmeter and get the voltage at a car power outlet (or,
in this case, the auxiliary power outlet in the inverter)? I think that's
clear to everyone in this thread except me.

Thanks.

 

In my original post I noted that it's the original manufacturer battery
(with 45K miles on the vehicle). The dealer service manager that I spoke to
brushed off the problem and said to just replace the battery, that 45K miles
means the battery should be replaced, etc., etc. While I don't discount
that, it seems that I should have *some* trouble starting the car if the
battery was weak. As it is, the car starts easier than most cars I've
driven, with just a touch of the key to the starter position.

 

Revving the engine will do NOTHING to increase alternator output voltage;

NOPE. Why? A silly little thing known as a voltage regulator. Been on
vehicles for over half a century now.

Amperage, on the other hand, may be increased slightly if you rev the
engine, but it depends on the system and how much draw there is.

--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

Then so what? If the battery will provide enough power to crank the car,

More rubbish. Cranking the engine is not a computer monitored function.
Thus, you can crank the engine till the battery dies. The invertor OTOH,
monitors power draw to confirm that it will have constant voltage/amperage
so as to not mess with stuff like a laptop. If the invertor finds a drop,
it'll shut down.

A load test will prove that a battery is capable of handling any load on it,
as well as noting condition. Its a basic test, and is the FIRST (AGAIN
WTF??) test one should do in diagnosing an electrical system problem.

Bullshit. I defy you to find a post of mine where I said replace the battery
BEFORE testing it. Second, as I discussed above, the starter doesn't care
how much it draws on the battery, nor does the ECM until it hits 10.5v, at
which point the injectors will not fire. The invertor OTOH, WILL (at least
should) cut power it if finds an anomoly which threatens the delicate
electronics it is feeding.

No, I start at the load center on the wall, you know, the big grey box where
all the circuit breakers are. Same box has the big ass cable coming in from
the street that feeds the house. SO yes, I DO check the power source in
troubleshooting a home electrical problem as well. What part of this is so
hard to understand? Check the source to be sure you have acceptable power
coming into the system.

Well, since I didn't suggest changing the battery before tests, perhaps I
will suggest you learn to read what I've posted.

--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

Here is what you said: "Have a load test done elsewhere, or simply
replace the battery." I accept that you made that statement in the
context of the 12.8v reading (which I don't readily accept as indicative
of a bad battery, but I will take your word for it at this point).
Also, I don't accept that a weak battery (one without a shorted cell,
which is not indicated by the information that we have) will in any way
pull down a properly functioning alternator - so the fact that the OP is
having undervoltage issues at the socket *with* *the* *engine* *running*
says to me that this particular problem is *not* caused by the battery -
it is a voltage drop somewhere else in the system supplying power to the
socket.

Except I still take exception with you that a weak (non-shorted cell)
battery would explain an undervoltage condition with the engine running
and a working alternator. Not to say his battery isn't bad or weak, but
it ain't causing this particular problem with the engine running.

Also - let the record show that, well into this thread, I was the very
first person to make the obvious suggestion of actually using a
voltmeter to measure the voltage *at* *the* *socket* - not Gary (not
that it matters, but...).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

There are two terminals that you need to touch the voltmeter leads to
with it in at least the 20 volt range. The shell of the socket is one
terminal, the button deep in the center is the other terminal - don't
let the same single piece of metal (a voltmeter lead tip) touch both
terminals at the same time or you'll blow a fuse or over heat some wires.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

How does one take a voltmeter and get the voltage at a car power outlet

Two probes, one red, one black. Put the red on the positive contact, and the
black on the negative contact. If your meter reads negative numbers, simply
reverse the probes. Beyond that, I'm not sure what you are asking.

--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

Mopar batteries have been known to go bad at 3 years, or last as many as 6.

As I stated to another poster, its quite possible that the invertor is more
sensitive to voltage drop than the starter. A starter will crank as long as
you hold the key, since it does not monitor voltage.

Again, test the power port with a meter, and you'll know if the voltage is
enough to trip the invertor or not.

--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

Mopar batteries have been known to go bad at 3 years, or last as many as 6.

As I stated to another poster, its quite possible that the invertor is more
sensitive to voltage drop than the starter. A starter will crank as long as
you hold the key, since it does not monitor voltage.

Again, test the power port with a meter, and you'll know if the voltage is
enough to trip the invertor or not.

--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

Your battery may or may not be wearing out, but if your inverter is
having an undervoltage problem with the engine running (i.e., alternator
putting out 14+ volts), then the battery is *not* causing this problem
(that could only happen if the battery had one or more shorted cells and
were pulling the alternator down - we have no indication whatsoever that
your battery has a shorted cell).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Here is what you said: "Have a load test done elsewhere, or simply replace

12.8v just after charging indicates to me that nominal after a "cool down"
might be lower than the invertor wants to see. However, as you admit, I did
suggest another load test prior to simply replacing it, this predicated on
the difficulty/cost of getting a second, more accurate test.

This according to the original post:
inverter works fine; but when the engine is off (with key in accessory
position), the inverter will run for a few seconds, give an error beep, and
then shut down.<<

....Indicates to me that the problem is in engine OFF mode. As such, its a
BATTERY problem.

Engine is NOT running. WTF?

And you are the first person that seems to think that the engine runs while
its off..... please check the OP if you doubt my words above.


--
Max

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

 

A regulator cannot force an alternator to put out full regulated voltage
if the alternator is not turning fast enough - often the case at idle on
vehicles with typical loads turned on.

No - amperage will not be increased *if* the voltage is already at full
regulation before rev'ing it up (which in many/most vehicles at idle, it
is not). At full regulated voltage, amperage is whatever the loads are
that are on. For a given load, the *only* time amperage will increase
with rev'ing is if the voltage were low (i.e., not into full regulation)
before rev'ing. Reving it up (usually no more than 1000 0r 1200 rpm
with typical light loads) ensures that it is getting the regulator into
full regulation (i.e., max. regulated voltage).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Check your post of 10:27 this morning ("Have a load test done elsewhere,
or simply replace the battery."). What do I win!?

Nay nay. See above.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

The ignorance of a dealer principal who would hire anybody EXCEPT a
good mechanic as service manager. Too many hire salesmen instead of
mechanics - can't for the life of me figure out why (that from a
mechanic who spent 10 years as service manager)