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ZL3AI > APRDIG 13.12.06 23:21l 256 Lines 10008 Bytes #999 (0) @ WW
BID : 9219-ZL3AI
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Subj: [APRSSIG] Vol 30 #9, 1/2
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Sent: 061213/2214Z @:ZL2BAU.#79.NZL.OC #:20407 [Waimate] $:9219-ZL3AI
From: ZL3AI@ZL2BAU.#79.NZL.OC
To : APRDIG@WW
Today's Topics:
1. Re: backup pwr systems (Charles Doughtie)
2. Re: backup pwr systems (VE7GDH)
3. House Temperature Probing (Drew Baxter)
4. RE: House Temperature Probing (Scott Miller)
5. Re: backup pwr systems (Charles Doughtie)
6. Re: backup pwr systems (A.J. Farmer (AJ3U))
7. Re: backup pwr systems (Chris Rose)
8. Re: backup pwr systems (Dale Blanchard)
9. Re: backup pwr systems (Tad Burnett)
10. Re: backup pwr systems (Joel Maslak)
11. RE: House Temperature Probing (Drew Baxter)
12. Receive Only APRS (M J)
13. Re: backup pwr systems (A.J. Farmer (AJ3U))
14. RE: Receive Only APRS (Robert Bruninga)
15. Re: Receive Only APRS (Jason Winningham)
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Message: 1
Date: Sat, 9 Dec 2006 10:47:01 -0800 (PST)
From: Charles Doughtie <n5exy_at_yahoo.com>
Subject: Re: [aprssig] backup pwr systems
FWIW I had two "smart" chargers (different brands) fail and boil two
relatively new deep cycle batteries dry. Even the smart ones need to be
monitored a bit.
73 de Charlie, N5EXY
South Suburban Greater Hutto
--- Dale Blanchard <wa7ixk_at_earthlink.net> wrote:
>Chris Rose wrote:
>>Leaving a battery constantly plugged in to a
>charger will cook and kill the battery. I have
>ruined more than one. I don't suggest that course
>of action. Having a battery available to connect to
>when mains go down is a better way to go. Some
>circuits are available to show how to do this. Some
>simple and some quite elaborate depending on how
>many raidos or scanners you have to take care of.
>>
>>Chris
>>KB8UIH
------------------------------
Message: 2
Date: Sat, 9 Dec 2006 11:15:17 -0800
From: "VE7GDH" <ve7gdh_at_rac.ca>
Subject: Re: [aprssig] backup pwr systems
Charles N5EXY wrote...
>FWIW I had two "smart" chargers (different brands)
>fail and boil two relatively new deep cycle batteries
>dry. Even the smart ones need to be monitored a bit.
What make and model were the "smart" chargers? Yes, if it isn't a
"maintenance free" battery such as AGM or gel, you do need to keep the
level up by topping it up with distilled water, but the levels shouldn't go
down much unless you are deeply discharging the battery and then charging
it a high rate all of the time. A true "3 stage charger" should charge the
battery at the (bulk) maximum rate, and then change to a fixed voltage at a
certain point, and then it should switch again to a lower voltage to
trickle charge the battery for maintenance. The charger type should match
the battery chemistry. Some batteries (flooded lead acid) should get the
occasional equalization charge at a higher rate to shake things up. With
the wrong charger, or one that isn't as "smart" as advertised, battery life
will be impacted. I've actually got a large battery bank that is down in
capacity right now. I'm playing around with a battery desulfator to see if
it can recover some capacity.
My backup power system is to keep computers (and other things) running.
Just to keep it on topic, it also powers a digi / IGate / IRLP node and
other things. Disasters like Katrina show how important it is to have a
backup power system. However, that was on such a massive scale that most
backup power systems would be severely taxed, but having some backup
capability is better than no capability. Most of my power outages are from
wind or snow in winter. Most are of short duration... less than 3 hours.
However, an outage of nearly a week is not unheard of. Here in southwest
BC, we had nearly two weeks of high winds and heavy rain, followed by a
week and a half of snow (OK, two days of snow, but it hung around a while)
and cool temperatures with some lengthy outages for some areas. Each
individual should decide how much of a "backup power system" they need and
go from there. Some will opt for none. Others will have a 60-100 Ah battery
and a smart charger and connect it when needed. Others will go for a lot
more capacity and automatic changeover. Some will have solar power and/or
generator backup as well. There are lots of options to choose from. Looking
at it from the APRS perspective, keeping digis and IGates running during
power failures could really make the difference between having no
communications and some communications. Of course, voice repeaters would
certainly benefit from backup power capability as well, as would HF
stations.
73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!"
------------------------------
Message: 3
Date: Sat, 09 Dec 2006 14:24:59 -0500
From: Drew Baxter <droobie_at_maine.rr.com>
Subject: [aprssig] House Temperature Probing
It's winter again in the Northeast and that means fun things like pipes
freezing and heaters going out.
I'd be interested to set up something that reported every hour to give me
an idea of what the temperature was inside a camp I don't often visit
throughout the season. If the heat fails, it could make a big mess of
things.
I see the Opentracker has an onboard temperature sensor. Does the OT get
hot in such a way that it could affect the readings from the onboard
sensor?
Has anyone tried anything like this? :)
Thanks.
--Droo, K1XVM
------------------------------
Message: 4
Date: Sat, 9 Dec 2006 11:50:12 -0800
From: "Scott Miller" <scott_at_opentrac.org>
Subject: RE: [aprssig] House Temperature Probing
It self-heats only if you're putting a significant load on the regulator.
You can also remote the sensor pretty easily. Or you can load the Dallas
1-wire weather firmware and connect a DS18S20 sensor. I've got one of
those in the garage - it runs about 20 feet from the tracker to my freezer
to make sure the defrost heater hasn't broken again. It's more accurate
than the on-board sensor and doesn't need any calibration. It also isn't
affected by voltage drop on a long cable since it's a digital sensor - it
generally either works or doesn't, with no degradation in accuracy.
If you load the weather firmware with no external sensor connected, it'll
just report the on-board temperature in APRS weather format. That lets you
get graphs on Findu. If you do have an external sensor connected, you'll
still get the on-board temperature in the status text. Check out
wx.findu.com/n1vg-3 for an example.
N1VG-3>APOT01:>Livin' in the fridge! 14.2V 23C
N1VG-3>APOT01:!3457.54N/12025.44W_.../...g...t-12OD1w
The board itself is at 23 degrees C, and the freezer is at -12 F. The
status text always reports in C, so if you want F from the on-board sensor
you've got to run it in weather mode. On the Tracker2 it's selectable.
As for calibration of the on-board sensor, it has a very linear response so
you only need a single-point calibration. Just check the real temperature,
see what the sensor reports, and enter the difference in the temp adjust
field.
Scott
N1VG
------------------------------
Message: 5
Date: Sat, 9 Dec 2006 13:58:59 -0800 (PST)
From: Charles Doughtie <n5exy_at_yahoo.com>
Subject: Re: [aprssig] backup pwr systems
One was a Wal-Mart (ugh) Everstart ((NEVERstart?)) Boating/RV Fully
automatic/manual for 12v marine/deep cycle model WM-51A-PE. I don't
remember the other. After aging a few years, it will no longer go into
maintenance mode, but is still good as a 10A charger.
------------------------------
Message: 6
Date: Sat, 9 Dec 2006 18:57:08 -0500
From: "A.J. Farmer (AJ3U)" <farmer.aj_at_gmail.com>
Subject: Re: [aprssig] backup pwr systems
Just some food for thought, if you have the battery hooked up to a load
while you are charging it, this prevents even a "smart" charger from
properly determining the state of the battery and that is why it boils over
the battery. It is not a problem with the charger - the charger is
designed to charge a battery under little or no load.
The best way to set things up is to isolate the battery from the load and
run the load from a power supply directly. The smart charger connected
24x7 to the battery under no load will charge and maintain the battery
properly. When the power fails, either manually switch the load over to
the battery or use some type of automatic transfer switch if you need
unattended operation.
Another solution is to use a solar charge controller and connect a power
supply to the voltage input where you would normally connect the solar
panels.
--
A.J. Farmer, AJ3U
http://www.aj3u.com
------------------------------
Message: 7
Date: Sat, 9 Dec 2006 16:10:24 -0800 (PST)
From: Chris Rose <kb8uih_at_sbcglobal.net>
Subject: Re: [aprssig] backup pwr systems
Untill the so called "smart" chargers lose their "smarts" and forget what
they are supposed to do.
Chris
KB8UIH
>With the proper smart charger it is ok to leave on all the time.
>Cheap trickle charger can kill batteries.
>Dale
------------------------------
Message: 8
Date: Sat, 09 Dec 2006 16:59:04 -0800
From: Dale Blanchard <wa7ixk_at_earthlink.net>
Subject: Re: [aprssig] backup pwr systems
A.J. Farmer (AJ3U) wrote:
>Just some food for thought, if you have the battery hooked up to a
>load while you are charging it, this prevents even a "smart" charger
>from properly determining the state of the battery and that is why it
>boils over the battery. It is not a problem with the charger - the
>charger is designed to charge a battery under little or no load.
I have a Marine charger that is designed to work with light loads or no
loads.
That is what the book says and why.
I have been using it in my Ham station with some radios on 24/7.
Keeps up OK. But it is a $150.00 charger.
It is difficult to find a proper charger due to the snake oil marketing.
If a company does not publish full specs. I will not buy one.
That is why I do not use a Deltran Battery Tender.
They publish the charge curves, but do not list the voltages.
A cheap charger normally has wide ranging manufacturing tolerence.
Some smart chargers are reverse engineered in China and do not meet the
origional makers specs.
Dale
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