[TenTec] emergency back up power

[Gary Hoffman]

I'll bet that the battery voltage, as delivered to the actual radio, is a
little low.

Going to a sine converter and 115 VAC power fixes this issue totally.

Gary

----- Original Message ----- 
From: "Denton" <denton at oregontrail.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Monday, March 05, 2007 12:14 PM
Subject: Re: [TenTec] emergency back up power


> I have been running 8-38 amp hour Powersafe (Hawker) gas absorption mat
> connected in parallel that also have each battery's B+ outlet fused, going
> to a MFJ power block for distribution to two vhf/uhf rigs and two hf
> rigs...a TT Paragon II and Omni VI.
> For some reason the hf rigs do not like this particular power setup and
will
> tend to draw too much collector current going into a flat antenna load
even
> when the rf power output is set at minimum....if I run the hf rigs on
> individual TT 961 power supplies, the condition does not exist. the
Paragon
> is more stable running off of my battery setup than the Omni.
> I am now wondering if I would be better off using the existing batteries
to
> feed a ups, such as an APC 2200,  and hooking up the individual power
> supplies to the ups.
> The batteries voltage range is from 13.02 to 14.16 vdc, with optimum
voltage
> of 2.27 vdc per cell, or 13.62 vdc per battery.
> ----- Original Message ----- 
> From: "Eric F. Richards" <efricha at dim.com>
> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
> Sent: Monday, March 05, 2007 1:44 AM
> Subject: Re: [TenTec] emergency back up power
>
>
> > At 12:20 AM 3/5/2007 -0500, Gary Hoffman wrote:
> >>Paul,
> >>
> >>My array of batteries can provide about 1500 amp hours, provided that
the
> >>discharge rate is kept reasonable.
> >>
> >>No discount sources that I know of.  That's because most batteries that
> >>have
> >>seen use have been handled so poorly that they have been significantly
> >>impaired.
> >
> > May I throw in a contrary opinion?
> >
> > I'm running on 800 AH (24 VDC) of hospital pulls.  They saw one year of
> > service and were yanked.  80 AH gel-cells.
> >
> > The inverter is an Exeltech XP-1100 (1.1 kVA) -- too small for a
> > legal-limit amp, but a fine sine wave inverter with less than 2% THD.  A
> > battery balancer lets me pull 12 volts directly for the various radios
> > that
> > use it.  A West Mountain Radio RigRunner distributes the 12 V through
> > Anderson PowerPoles.
> >
> > It goes without saying that I fuse the crap out of everything.  The
> > inverter has a separate 200 A Class-T fuse.
> >
> > The XP series from Exeltech is their "low cost" inverter line, and the
> > 1100
> > is as big as that series gets.  If you want more power, you need a rack
> > mount module with 1 kVA modules stacked with controllers,  with the
option
> > of redundant power, etc.... and the cost goes sky high.
> >
> > ...oh, those batteries?  Well, they're getting old.  I've gotten almost
10
> > years out of them, and need to replace them.   But then, they only have
> > done two deep/complete discharge cycles.  I'll have no problem with
using
> > hospital pulls or NOS again.
> >
> > For those still reading, the charging system is 400 W of solar panels
> > through a PWM charger with sense lines and temperature compensation.
> > About
> > $100 back in the day, and there are much better ones out there today.
> >
> >
> >>Special electronics are not especially hard to work up yourself.  You
must
> >>avoid over or undercharge, which is pretty much a matter of voltage
> >>regulation.  And every so often you must apply an equalizing charge to
> >>make
> >>sure that all batteries are properly topped up.  You can Google that
> >>phrase
> >>and come up with lots of stuff.  Or look at Home Power Magazine.
> >
> > That's fine for wet-cells, but I prefer the safety of gel cells at the
> > cost
> > of energy density and $$$.  I'd go with a commercial circuit if you
> > haven't
> > done a charge circuit before.  (You only equalize a gel-cell once, and
> > then
> > you throw it away. :-))
> >
> >
> >
> >>Overspend on the batteries and make savings elsewhere if you can.
> >
> > Again, I think you can get away with certain things with the
> > batteries.  New-old stock is fine, as long as they aren't more than 18
> > months old, as are hospital pulls.  Wet cell types that have never seen
> > electrolyte should be fine as long as they weren't physically damaged
> > (dropped, etc.).  However, UPS pulls from non-life-critical systems
aren't
> > worth it.  Pulls from repeater sites are a no-no.
> >
> > It helps if you know people who've been through this before in your
local
> > area.  At local hamfests here in Colorado, there are dealers who work in
> > good faith and there are the rest.  Find out from someone who's been
> > through it all before.
> >
> > Regards,
> >
> > Eric F. Richards, KB0YDN
> >
> > --
> > Eric F. Richards
> > efricha at dim.com
> > "The weird part is that I can feel productive even when I'm doomed."
> >  - Dilbert
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec at contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
>
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