On 02/13/2011 08:17 AM, Percival P. Cassidy wrote:
On 02/13/11 03:14 am, No Spam wrote:

I'm looking for charger/maintainer -- either an off-the-shelf unit or a
schematic so I can build my own -- suitable for a flooded deep-cycle
battery, either a pair of 6V "golf cart" batteries in series or a Group
31.

I don't want an RFI generator: I already have one.

I already have a few 13.8V 25A power supplies, one of which I would be
quite willing to "crank up" to a higher voltage to compensate for the
voltage drop in the control circuitry.

Something like the West Mountain Radio "Super PwrGate" (PG40S) would
work, although the automatic switch-over feature is not essential. That
device is intended for Gel-Cell and AGM batteries and not recommended
for flooded batteries -- absorption-charge voltage too low and
float-charge voltage too high, their tech support people tell me.

I am quite happy with my IOTA DLS-45 with the IQ Smart Controller

http://www.iotaengineering.com/iq.htm

Once a week it equalizes my batteries using 14v pulses. The batteries are
on their 14th year and can still run my shack for 5 days. (down from a
week when I initially purchased the batteries and charger)

I wish I'd known about that IQ unit before I bought an Astron RS-35A
just a month or two back.

I was hoping I could find something not too expensive to take power from
that P/S or from one of my RF-quiet "switchers" to look after the
batteries. Texas Instruments has battery-charging ICs, but I haven't
seen a practical circuit that uses one.

"Perce"



You do not need anything too fancy...
to "float" the batteries all you need to do is keep them at approx 2.25
volts / cell...so it's possible that your 13.8 v charger will do the job...

You can test it by checking the total voltage after a 24 hour period...

ideally, a 12v battery should float at about 13.5 volts.

If the float voltage is a little higher or lower it won't be too
critical...but make sure it's well below the 14.2 v gassing point.

I've been in the lead-acid battery business for 36 years...
so have quite a bit of long term empirical data