How Diodes & Battery Tender Work Re: <VV> Re: Battery Tender Problems

[FrankCB@aol.com]

Bob,
       You might consider a diode as a check valve that only permits the flow 
of electric current in one direction thereby rectifying AC from the 
transformer to the DC that the battery needs.  The AC, as its name states, alternates 
from positive to negative and the diode "check valve" allows only one of these 
(the positive OR the negative, depending on how its installed) to flow into 
the battery and charge it.
       A number of years ago I received a Battery Tender Plus from son Jim 
and have used it constantly to keep the original stock battery on my 1995 
Pontiac TransSport charged and ready.  That battery is now over 9 years old and 
still functions perfectly as long as I don't leave it disconnected from the 
Battery Tender Plus for a few weeks at a time. Modern cars have a small but steady 
drain on the battery that will, after some weeks without running the car, drain 
an older battery.  The Battery Tender works by initially providing a higher 
charging rate (more amps) until the battery voltage reaches about 14.2 to 14.5 
volts, thereby mimicking the charging system in the car.  But at that point, 
the sophisticated electronics switches the charging rate to a much lower value 
and thereafter continues to maintain the charging voltage at 13.5 volts.  At 
this voltage level the battery is maintained without overheating or decomposing 
the water in the electrolyte so the unit can be left connected indefinitely 
(like all winter) and still be ready to supply full starting capability for the 
spring "reawakening".  Continuous charging at 1 to 2 amps from a "trickle 
charger" is definitely NOT the way to go for a long period of time.
       Regards and see you at Lexington,
       Frank Burkhard

In a message dated 6/3/04 9:25:27 AM Eastern Daylight Time, 
nortechcorp@optonline.net writes:

> Phil asked:
> 
> Wanted to "poll" the group on experience with the "Battery Tender Plus"
> 
> JR replied:
> 
> Try a doorbell transformer.  I think they put out about 2amps.
> 
> Harry added:
> 
> Don't forget the diode.
> 
> Bob now asks:
> 
> And the diode does... what?
> 
> 
> Robert W. Marlow
> nortechcorp@optonline.net