Cor van de Water via EV wrote:
Since this is used for charging - you might be able to cut the wire
from the contactor that feeds it from the aux battery and instead,
connect the power to the contactor coil from a small 12V supply powered
by the charging AC, so it only powers up when actually charging?
Yes; if Steve's problem is to power the contactor needed for charging,
then the most straightforward way to do it is to power the contactor
coil from AC power, one way or another.
The BMS itself is probably permanently connected to the pack. It will
draw some "vampire" current to run down the pack by itself, even without
this relay issue. I would guess your relay solution doesn't need to draw
"zero" current -- just a current that is as low as the BMS itself draws.
There are many low-power ways to drive the relay. A small sensitive reed
relay can be used to operate a much larger power relay to shut off the
charger. Or a very low power optocoupler can be used to drive a triac
that switches the charger.
If you truly need "zero power", then some form of latching relay can be
used.
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading
Or do these great deeds, worth repeating.
-- Ben Franklin, from Poor Richard's Almanac
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA
(http://groups.yahoo.com/group/NEDRA)
