The seller may want to consider placing an additional ad in the
EVtrandinpost charger section
http://www.evtradinpost.com/list/29

Our evdl sys admin has placed a K&W BC-20 manual pdf up on the evdl.org
site
http://www.evdl.org/docs/bc-20.pdf

K&W BC-20 was a fairly common charger in the early 1990's (what I mostly
saw EAA members had when I was just starting to learn EVs). A good but
manual charger, that needed to be set to the correct voltage. That
voltage would change over the life of the pack and when pack
temperatures changed because of the outside seasonal weather (slight
adjustments, no biggie, adjust the slotted pot in the top of the K&W box
and use a Volt meter). 

As stated in the ad below, the design would charge to a set pack
voltage, and then hold that voltage letting the current slowly
reduce/drop/taper off (in the morning after a 10+ hour overnight charge,
when you look at the on-board TMS meter, you see the current has dropped
off to nil, thus the pack for all intent and purposes, was 'recharged'.
http://ecomodder.com/forum/showthread.php/open-source-6kw-charger-who-whats-what-features-13013.html#post171414

Note: if a daily driver wanted to do a weekly maintenance overcharge (4A
for 4hours, like the third stage of a Zivan charging algorithm), you
have set the voltage higher, and then afterward, return the setting back
the way it was (its a manual charger, you are the smarts).

The built-in meter does not read RMS instead it reads (according to what
K&W emailed me years ago) TMS. So, to get an average 10A DC charging
current, the built-in meter would read 7A, and you needed a healthy 20A
120VAC breaker-ed circuit (no cheap China breakers please, they trip/pop
too easily). 

The manual mentions using 14 gauge wiring (i.e. the extension cords
feeding AC power to the charger). But I found 12 gauge is a minimum. The
charger's AC current draw is spiky, so you need a larger breaker than
the amount of average current you are pumping into the pack (a 20A AC
breaker to give 10A DC in). That spiky charging can cause RFI which will
mess up AM/SW radio reception.

Placement of the K&W BC-20 can be under the hood (I had seen many
installed in the rear of the interior to avoid moisture). The Escort
Wagon EV I had for a short while had one mounted under the hood, and I
had no problems with it what so ever
http://brucedp.150m.com/escort/escort991221-12.jpg
http://brucedp.150m.com/escort/

Way in the past, there were posts on the evdl asking why the BC-20's
built in gfi kept tripping, thus the EV could not be charged. The BC-20
was not bad (there was nothing wrong with it). It was the way the
converter had laid out the wiring and the placement of the BC-20. A
build up of moisture can allow for leakage current that will trip the
gfi. Their short term resolve was to dry everything out. Later, the long
term fix was to rework the wiring and charger placement to minimize that
condition.

BTW there was another transformer that was also sold with the BC-20 to
be able to charge a 132 or 144V pack, the LB-20 is not that transformer
and is specifically good for up to a 120VDC pack. If you use the other
transformer, you need a different resistor that goes inside the BC-20
box. Also, the BC-20 box itself is fairly light. Its the power
transformer that is heavy.

There are several EVs on the evalbum that are happily using a K&W
charger, here are a couple
Jared Leverington's 1984 Pontiac Fiero SE
http://evalbum.com/1381

Jason Bloomberg's 1993 Eagle Summit Wagon
http://evalbum.com/1949


{brucedp.150m.com}



-
http://www.ebay.com/itm/K-W-BC-20-Battery-Charger-LB-20-Booster-48-120-VDC-Battery-Packs-EV-/200879219512
"I just removed this K&W Engineering BC-20 2 kW Charger and LB-20 Line
Booster from an Electric Vehicle (EV) in which it was being used to
charge a bank of ten 12V deep cycle lead-acid batteries.

The BC-20 charges battery packs that are from 48 VDC up to 108 VDC (four
nine 12 VDC batteries).  The LB-20 is a large (and heavy) transformer
that allows the BC-20 to charge up to ten 12 VDC battery packs (120
VDC).
It charges using constant current to bring the battery the gassing
voltage and then constant voltage to finish.

They both are in good operating condition.  They are both currently
mounted on a piece of plywood.  I will remove them from the plywood on
request.

Also on request, I will consider separating the two items and selling
them individually.
An instruction manual  and application/installation printout are
included.  You can see and download an instruction manual here.
May be picked up in northern NJ, near NYC"s GW Bridge.  It's heavy, so
shipping within the continental US will be $30 - more elsewhere."
-


-
On Mon, Jan 14, 2013, at 03:14 PM, Len Moskowitz wrote:
> I put my old charger up for auction on eBay:
> K&W BC-20 Battery Charger & LB-20 Booster, 48 to 120 VDC
> [ http://www.ebay.com/itm/200879219512 ]
-

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