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[Shop-talk] [Roadsters] Slightly OT--car won't start

Subject: [Shop-talk] [Roadsters] Slightly OT--car won't start
From: jblair1948 at cox.net (John T. Blair)
Date: Thu, 22 Dec 2011 10:09:10 -0500
References: <4cd656b.75bff.1346627229a.Webtop.47@charter.net> <4EF3411F.5010005@comcast.net>
At 09:39 AM 12/22/2011, Bob Spidell wrote:

 >>re: "I didn't know that a battery can show fully charged and still 
be bad (a new thing learned!!!). "

 >'Fully charged' usually just means the battery shows nominal 
voltage (around 12.7V, IIRC).  You can
 >charge a battery to this level--I believe it's called 'flash 
charge' or similar--but a dying battery will
 >discharge and the voltage will drop immediately when any load is applied.

 >I sprung for a battery load tester the other day.....

Having a true battery load tester is great!!  But I also suggest that 
everyone pick up a cheap multimeter from
Harbor Freight, especially when they go on sale, less than $5 and 
carry it in your car.  I have one in every
car and every tool box, on the garage bench, and a couple in the house.

To test a car battery, place the leads across the battery you should 
see 12V or more.  Then have some one
try and start the car.  If the voltage goes below about 11 V then the 
battery is dead.

A volt meter will show a battery is charged even though it's dead 
because the meter doesn't draw any
current.  So you have to put a load on the battery, like trying to 
start the engine or turn on the headlights.

A quick easy test.

Then when the engine is running over 1500 rpm the voltage should read 
14 - 14.7 V.  If not then you
probably have a bad alternator and it can't charge the battery, or 
the battery could be bad.  But most of the
time is the alternator or a bad electrical connection.

For more info. check out the article "The Starting System"

http://www.team.net/www/morgan/tech/electrical/starting/art026.html

on my Morgan web page.

John



John T. Blair  WA4OHZ     email:  jblair1948 at cox.net
Va. Beach, Va
Phone:  (757) 495-8229

           48 TR1800    48 #4 Midget    65 Morgan 4/4 Series V (B1106)
      75 Bricklin SV1 (#0887)    77 Spitfire    71 Saab Sonett III
                        65 Rambler Classic

Morgan:    www.team.net/www/morgan
Bricklin:  www.bricklin.org

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