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
If you can read this - Thank a teacher!
If you are reading it in English - Thank a Vet!!
From Dennis Prager - The American Trilogy:
e pluribus Unum, "from many, one."
In God We Trust
Liberty - the power of choosing, thinking, and acting for
oneself; freedom from control or restriction