Travel Forum / Travel Types / RV Travel / August 2008

Yes.  I've tested two.  One is the Battery Minder (or Tender, I can't recall
which is which, anyway, the one with the pushbutton in the center) and one
built from plans from this website that is now deceased.  

http://shaka.com/~kalepa/desulf.htm (still available at the Wayback Machine)

This page is still live and has some of his work on it.
http://www.dallas.net/~jvpoll/Battery/PerformanceDoc23/PerformanceDocumentation_
Units23.html

Both worked as advertised.

The one that I built is much more powerful than the Battery Minder but the BM
(heheh) does work.  In the test I applied it to an old Group 27 battery that
had been sitting around for a couple of years.  Some folks allege that merely
doing a long term charge will bring 'em back.  After several weeks of sitting
on a dumb charger adjusted to equalize voltage, it tested out at 20 amp-hours
and didn't improve over several cycles.

I put the BM on and left it for a couple of days.  The improvement, if any,
was statistically insignificant.  As I do more often than I should, when I get
an adverse result from an experiment, I tend to walk away, at least for
awhile.  That's what I did in this case.  I shoved the battery with the BM
attached under the bench and forgot about it.  

About 3 weeks later I thought about the battery and hooked it to my discharge
tester.  Amazingly enough, it now registered right at 80 amp-hours.
Essentially new.  Most batteries that I've actually discharge-tested have
their capacity over-stated.

I did some more experimenting with the battery and found something curious. As
long as a maintenance charger remained attached, the battery maintained its
capacity.  It could be discharged and recharged as normal.  But if allowed to
sit idle for awhile, it lost much of its recovered capacity.  Not stored
energy but the ability to store energy.  I have no idea why, though I
speculate that maybe the pores in the hard sulfate that pulsing is supposed to
open closed shut again.

In any event, that battery and the one just like it that I tested the
home-made unit on are still powering my UPS as part of a large string of
series-paralleled 24 volt batteries.

Pulse power matters.  The one that I built from plans is much more powerful
than the BM and it did its thing in days.  It's self-powered from the target
battery.

You might want to look around and see if you can find a kit based on the
Alastair Couper design.  Most anyone can solder that small of a kit together.
Or heck, have it sent to me and I'll assemble it and send it back.

I've had a BM attached to my house batteries continuously since I ran the
test.  It is not plugged in.  The pulser part works without AC power.  I've
made so many other changes that I can't say if it made any difference or not
but it sure hasn't hurt anything.

John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
What do you call a blonde's cranial cavity?  Vacuum chamber?