On 1/28/2013 4:44 PM, Lee Hart wrote:
On 1/28/2013 4:54 PM, Chuck Hursch wrote:
I think the Elcon gets set up with IUI for floodies, with perhaps even a
fourth-stage trickle charge.
The final xxI in an IUI charge cycle is generally for equalization.
After the battery is nominally "full", it keeps charging at some low
current until some cutoff condition is satisfied. It might be for a
fixed time (1-2 hours), or until a particular voltage is reached, or
some other condition. But this final xxI stage should in no case last
more than a couple hours.
A lead-acid battery should never be trickle charged. It is bound to
overcharge it. "Trickle charge" means continuing to charge at some low
current forever, regardless of what the battery voltage is.
I would have to wonder how one then would handle an old pack that's got
some shorts in some of the cells, along with the fact that some cells
just don't charge as fast as others. As I mentioned about a year ago,
last March I think it was, I watched the sg in a cell in a battery that
I pulled out of the pack go from 1260-ish to 1190-1200 just sitting
there on the deck for about a week. What I've gotten into doing over
the last year or so is just float charging the entire pack w/
variac/rectifier to the tune of an amp or two. I figure I can offset
the shorts as well as slowly equalize the pack. I'd likely be out of
the game with this pack by now if I hadn't done this.
The other thing I'd like to hear from the battery experts is how would
they handle a new pack. My new pack, once I get it before too many more
months, is probably going to sit a lot. During the dry season in the
summer, I will be biking to work four days of the week, and drive one
day of the week, folding all my errands and grocery shopping into that
one day if I can manage it that way. I've already been working into
this mode for the last two years since the CalPark Hill tunnel has
opened making it much easier to bike to work. My car hasn't moved for
this last week, since we've had a dry spell during the rainy season in
the winter. But we get some rainy stretches, the car will be going the
majority of the time, and the bike cools its heels (this is fair-weather
biking). I'm inclined to not have the car on charge while it is
sitting. A new pack has minimal self-discharge and shorts.
Equalization once every month or two should keep the flock together.
The thing that bugs me is that a pack that sits for awhile is almost
like a green new pack, you have to kinda break it back in and keep the
amps down to avoid blowing the active material off the grid (something
I've seen Roland and Cor mention). Is that because the paste tends to
lose its structure from gravity, and then there is some sulfation? From
what I've felt of the black stuff that gets on the bottom of the caps,
it's very thick and gooey - almost like cold molasses.
So that's kinda why I'm shooting for the fall to get a new pack. It
will be easier to swap in the new pack while it's dry outside and I
don't have to be carrying batteries up and down wet steps (after I've
processed them on the deck - grind the lifting tabs off of eight batts
to fit under those front racks, for one thing). And then shortly it
will be rainy season and I'll be using the car more. Let the old pack
sit during this summer.
[snip]
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