Re: [MV] Is my AMMETER hooked up backwards??

From: Buzzard (buzz@toast.net)
Date: Fri Sep 01 2000 - 05:59:58 PDT


Only one thing to add Gil...

If you are showing charging all of the time it's not good. You will boil
the electrolyte out of your battery.

-=-

----- Original Message -----
From: "Gil Huguley" <Gil@huguley.com>
To: "Military Vehicles List" <mil-veh@skylee.com>
Sent: Thursday, August 31, 2000 11:30 PM
Subject: Re: [MV] Is my AMMETER hooked up backwards??

> Come on guys! The ammeter reports on the health of your electrical
storage system. If it is "plus" or charging, you're ok. If it's "negative"
or discharging you are evenually going to be in the dark. I know many of
you are late to the technical side of life and I do not fault you for it,
but this is pretty basic. So, if I can help the "unwashed" (sorry, couldn't
resist), in all good faith, I will try to assist.
> Regards to all electrical incognitizito,
> Gil
>
> >>> <mblair1@home.net> 08/31/00 07:34AM >>>
>
> Well, I don't know, but *if* the correct convention for that ammeter
> is to measure current supplied by the bateries to the vehicle (i.e.,
> "+" means current flowing out of the battery), then your ammeter's
> behavior sounds reasonable to me. Here's my interpretation of your
> findings:
>
> "Kelly, Robert" <Robert_Kelly@FCEINC.COM> wrote:
> > With ignition OFF, main headlights ON, ammeter reads/moves to the
POSITIVE
> > range.
>
> Big load, current flowing out of battery.
>
> > With lights still on, engine running at low idle, ammeter reads a
> > steady "0".
>
> Charging at the same rate that the lights are discharging, so zero net
> current flow at the battery.
>
> > At anything over idle, ammeter needle goes to NEGATIVE.
>
> With the engine revving faster, the generator supplies more current
> than the lights draw, so the current starts to go negative at the
> battery.
>
> > The ammeter, when the vehicle is runing at anything over a low idle
> > without lights on, appears to behave correctly, that is, the needle
> > jumps to the far negative range for a moment then slowly settles
> > back to the halfway point between 0 and far neg. range. With the
> > lights on (under load) the needle settles back a little ways towards
> > 0.
>
> The charging current should reduce as the battery takes on charge.
> Turning on the lights reduces the effective charging current even more
> by robbing some of the charging current.
>
> So, it might be backwards; I don't know what they meant by "+",
> because I've only seen "C"/"D" meters in cars, but the behavior seems
> consistent with a functional charging system, and it's conventional
> in electrical engineering for power supplies with ammeters to indicate
> positive current when they're supplying power (i.e., when your battery
> is being discharged, if you think of it as a power supply), and to
> indicate negative current if power is being forced into the supply
> from an external source (often right before the magic smoke comes
> out and the supply stops working :-).
>
> --
> Mark J. Blair, KE6MYK <mblair1@home.net>
> PGP 2.6.2 public key available from http://pgp.ai.mit.edu/
> Web page: http://www.qsl.net/ke6myk/
> DO NOT SEND ANY UNSOLICITED COMMERCIAL EMAIL TO THIS SITE
>
> ===Mil-Veh is a member-supported mailing list===
> To unsubscribe, send e-mail to: <mil-veh-off@skylee.com>
> To switch to the DIGEST mode, send e-mail to <mil-veh-digest@skylee.com>
> To reach a human, contact <help@skylee.com>
>
>
> ===Mil-Veh is a member-supported mailing list===
> To unsubscribe, send e-mail to: <mil-veh-off@skylee.com>
> To switch to the DIGEST mode, send e-mail to <mil-veh-digest@skylee.com>
> To reach a human, contact <help@skylee.com>



This archive was generated by hypermail 2b29 : Tue Oct 24 2000 - 20:55:34 PDT