[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: (ET) charger
- Subject: RE: (ET) charger
- From: "Elie, Larry (L.D.)" <lelie ford com>
- Date: Wed, 30 Apr 2003 11:29:55 -0400
- Delivery-date: Wed, 30 Apr 2003 11:44:45 -0400
- Envelope-to: elec-trak-outgoing cosmos phy tufts edu
- Hop-count: 1
- Sender: owner-elec-trak cosmos phy tufts edu
My GUESS (as I wasn't there...)...
I think they feared that some people would be using the ET on a plug in
the garage or barn that had
other 'issues'. For example, voltage drop due to other loads, or droop
from a long cord. The
scenario would have gone like this...
Joe plugs in the ET at 6:00 in off a 50' extension cord. Although his
garage is 115V, the voltage
at the end of his cord under load is about 100V. He charges for 2 hours,
and then... he plugs
something in on the other leg of the 230V going into the garage. The
neutral shifts. The charge
rate changes a LOT. Then he plugs in his saw, same line, it changes
AGAIN. Yes, they wanted
constant (or more likely CONSISTENT) voltage. They knew the current
changes would change the
voltage, but they knew that Joe would be plenty mad when his batteries
that charged in 5 hours on
Tuesday didn't charge in 5 hours on Thursday. The customer is ALWAYS
right, and Joe now 'knows' he
needs new batteries before the warranty ends. I believe battery life (or
better... charging) was
what killed the ET. Dealers replacing things that weren't 'broke' to keep
their customers happy.
Next time the dealer sold them a John Deere or Bolens.
Again, that's just a guess; there may be other reasons to use the charger.
I work for a big company
(Ford) and sometimes we use a ridiculously expensive (more likely
ridiculously cheap...) part just
because of packaging, availability or some deal cut with a vendor. Those
are probably just as likely.
From: Bob Murcek [mailto:rmurcek geisinger edu]
Sent: Monday, April 28, 2003 5:09 PM
To: elec-trak cosmos phy tufts edu; lelie ford com; nagidog starband net
Subject: RE: (ET) charger
The transformer in the charger is ferroresonant for voltage stability,
right? What's your take on why GE went to that extra expense?
>>> "Elie, Larry (L.D.)" <lelie ford com> 4/28/2003 10:51:02 AM >>>
Engineering is basically the art of compromise.
GE knew that fast charging was a selling point. The charger they designed
was OVER 1000W (it varies with how low the batteries are) because most
people in 1970 had 15 Amp outlets. The timer is all there is... BUT...
remember, this is not a constant-current charger. Nor is it even really
constant voltage, because the load is a major part of the circuit. The
current is the limiting factor with low batteries, but eventually as the
voltage goes to 42 or 44V, the current going into each battery has
dropped, and the drain at the 120V outlet has gone down from 1000W. You
can check this with a Hall-Effect current meter at the batteries, and at
It isn't bad for the application, and very good for a 1970 'cheap fix'.
From: Jeremy [mailto:nagidog starband net]
Sent: Sunday, April 27, 2003 3:28 PM
To: elec trak yahoo group
Subject: (ET) charger
I finally got my e-12 in working order and just mowed about an acre of
hilly, very bumpy ground. It did great, really a tough machine. I have
noticed that the charger really sucks the juice, about a 1000 watts when
charging. This seems great if you just want a quick charge and get back
to mowing, but must be very hard on the batteries and is too much of a
load for my solar system. . . I can do it, but would bring down my
available solar power 20% for just one hour of charging. Spread over time
the load is not to big for my solar. I think a DC to DC converter putting
out 200 or 300 watts would charge more efficiently and put less strain on
my solar system. Also, my charging switch-dial has letters from a to G on
it, but I have not noticed a difference in amperage depending on where the
dial is set. Is this dial strictly a timer. What is the preferred method
of charging using the onboard charger. Short spurts over time, one big
long charge. Basically looking for the !
low down on charging technique.