nuckolls.bob(at)cox.net Guest
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Posted: Tue Mar 25, 2008 3:48 am Post subject: [!! SPAM] Re: Rotax 582 Starter Problem? |
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At 10:58 PM 3/24/2008 -0700, you wrote:
Quote: | At 03:00 PM 3/24/2008, you wrote:
>In all likelihood, your battery is simply gone south
> with loose connections or bad switching running in
> second place. The foregoing suggests that with some
> measurements, it's pretty easy to tell what needs to
> be done before you get out the wrenches or go into
> the swaptronics mode of troubleshooting.
Bob,
You were right, the battery had suddenly and inexplicably gone
south. When jumped with an enormous RV battery the 582 still had a
difficult time starting, but it started. The dead battery wouldn't accept
a charge, (measured by the load meter,) so I guess it was well and truly
dead. I tried jumping from various locations, eliminating various wires,
and the engine started slowly every time. I was unable to eliminate one
wire, though because of access, so that will have to wait until I can
pull the engine. I'll then be able to check the starter too. I'll check
cranking voltage against your recommended numbers first, though.
As an aside, how do the "low amp" testers work? (E.g.
DHC BT002 Battery Tester, Auto Meter BVA-350 Battery Tester)
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I've seen these kinds of things in the repair shops.
These are obviously NOT load testers in the usual sense.
There's no way these little fellers can accept that much
energy and dump the heat through those little leads and
small hand-held cases.
My guess is that they're internal impedance testers
of some variety. Hit the battery with 100A for a few
milliseconds, get a quick reading, compute internal
resistance by dividing delta-E by delta-I. Obviously,
they have many other features too. It would be
interesting to get my hands on one and watch it do
the full bag of tricks.
I did a design for a client some years ago for a
cranking system tester. It was nothing more than a
processor driven data acquisition system that took
6 readings of voltage around the system referenced to
battery(-) terminal. It filtered the short term
perturbations and offered a digital display of
minimums and averages for the 6 measurement points.
With one setup and one short cranking interval, it
would map the system's voltage drops. I don't know if
that ever went to production. Haven't heard from them
in years. It was the first time I was able to take
advantage of the agility offered by microelectronics
to make measurements that even the most skilled
observer with a multimeter would not be able to duplicate.
That design had a lot of components that are now
contained in a single micro-controller. It would be
VERY easy to do the same product today with a bill of
materials of less than $30! It could even offer 8 to
12 channels of monitoring capability.
Bob . . .
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( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
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