Re: Those days when nothing works
- From: Lawrence Glickman <Lawrence_Glickman@xxxxxxxxxxx>
- Date: Fri, 16 Jun 2006 11:04:18 -0500
On Fri, 16 Jun 2006 13:54:38 GMT, <HLS@xxxxxxxxxx> wrote:
Was planning to go out of town the other day, and my battery in the 97
Dodge Custom Van was dead
as hell. In my haste, I checked all the interior lights, etc, and put the
charger on it overnight.
The next morning, the charge indicator on the charger indicated low, but I
took a reading with a newish
DVM and decided to go with it. Drove 8 hours and no trouble.
I checked the voltage on the battery, at rest, with the same DVM and got a
whopping 13.8 volts. Whoa!
Dug out my old dependable DVM, and got 11.72.
Tried both meters on a fresh AAA battery, the old one gave me 1.56 volts,
the new one gave me 1.76 volts.
No doubt which one was right, I guess.
Well now you have it. A known *good* reference, like a fresh AA
alkaline battery, and you can check your meter to see if it is funky
in that low voltage *range*
Mine is crapola. Big pile of steaming crapola, which I bought for $20
at Harbor Freight. What would you expect? Lab Quality for $20?
Fired up the van and took the voltage reading running. In the high 13 volt
range...
Took off the negative terminal and measured resting (parasitic)
current...Next to nothing. Just a few milliamperes.
My parasitic drain is ELEVEN ( 11 ) MILLIAMPERES after the GEM Module
turns off ( about 3 hours ). Can I believe it just cause the meter
says so? Only my hairdresser knows for sure.
This tells me that it is time to change the battery-
How do you figure that !?!????!!!
But it also reinforces something else very basic... don't assume that your
voltmeters, etc, are correct just
because they are new. You can lose a lot of time and money following leads
from uncalibrated and inaccurate
equipment.
Nuf said...
The cost difference between cheap and expensive meter is the
tolerances of the components used in assembly ( IOW quality of
components ). I get 1.611 VDC on my cheapo meter reading a New in the
Box 1.5 volt AA alkaline. That can't be right. Cheapo meter sucks
rocks. What is it good for? I DON'T KNOW.
Now I measure this same battery with my clamp meter which has a
voltmeter function, and -that- says 1.595 VDC. This meter is $100. 5
times more expensive ( but it does tricks like measure current also ).
Is it possible this battery is somewhere between 1.595 and 1.611 VDC
in Reality? Who knows? Maybe when it is under LOAD, like in an
active circuit, but sitting here by itself doing nothing, with a 10
Megohm impedence meter connected to it...one is left to wonder.
Who wants to do the $300 experiment? Who wants to go out and spend
$300 just to find out the battery REALLY IS 1.6 VOLTS DC?!!!!!!??????
Nobody.
So...let's move along, and draw no hard and fast conclusions about
your having to replace your battery, because we have to know it's
specific gravity for each cell if it is not a sealed battery, but
rather a *wet* one with caps. And that SG has to be adjusted with a
temperature table, which you can easily find on the web.
Just going by the meter(s) isn't good enough justification, unless
your battery is OLD and/or your alternator/regulator is fubar, in
which case, you're looking at some money sonny.
Lg
.
- Follow-Ups:
- Re: Those days when nothing works
- From: HLS
- Re: Those days when nothing works
- References:
- Those days when nothing works
- From: HLS
- Those days when nothing works
- Prev by Date: Re: HELP!!!!
- Next by Date: Why do car manufacturers charge so much for replacement parts?
- Previous by thread: Those days when nothing works
- Next by thread: Re: Those days when nothing works
- Index(es):
Relevant Pages
|
Loading
