[aprssig] Quieting Honda Generator (was) Portable Ops from 12vvia115 VAC

Sat Jan 1 14:50:37 EST 2005

Well, this method works, and is also commonly done.
But you've gotta watch out for a few things.

1) If you use a regular old deep cycle or other style
car battery charger, they have very dirty outputs.  You
risk introducing these problems into your 12v side.
The batteries will "sink" this somewhat, but probably not
All of it.  This is the way most folks do it because it
Utilizes parts they already usually have on hand.

2) You can eliminate problem #1 by using a good quality
multi-stage charger.  But these are often as much or more
expensive than a decent battery.  These chargers will also
solve problem #2 which is "cooking" your batteries due to
overcharging, either too much charge current (usually not
the issue with small 10amp chargers), too much voltage 
(chargers that don't monitor battery voltage or charge rate),
or even undercharging which happens a lot.  It's fairly easy
to charge a bettery up to 90% or so, but the last 10% takes the
longest and is the most critical as far as overcharging etc.
Failing to fully recharge does as much harm to batteries to
Cause premature failure or reduced lifespan (not getting all
The charge cycles a battery should).  You see this in RV's a
Lot.  They usually have massive DC supplies like 30-50 amps
For powering all the 12v stuff when plugged into a power main.
These also include a charger or trickle/charger combo but
Seldom di any monitoring of battery health, so keeping the RV
Plugged in for long periods will just boil away the electrolyte.

3) The best way to determine battery charge state is by specific
gravity, which is a hassle, but actually easy to do.  Although
it really can't be automated or incorporated into the actual
charging system, it is very useful periodically when doing #4.

4) If you have a battery bank, each battery will tend to charge
a little faster or slower and even batteries of the same type and
size will exhibit slightly different charge and discharge rates.
So over time they begin to get all out of whack if they're merely
Charged as a bank all together.  So you should do a periodic
Equalization to bring them all back as close to 100% as possible.
This involves careful monitoring of voltage, current and specific
Gravity.  You nail em with around 17-18 volts and charge the heck
Out of them, then when you get close to 90% you back down and
Watch voltage and specific gravity to achieve 100%.  This also
Helps put back the electrolyte state and clean the plates by
Removing deposits that reduce charge capacity.  You MUST be careful
Not to get them too hot or you'll vent off the electrolyte.

5) The most dangerous thing about using batteries is health
related.  Unless they are gel cells, which most of us can't
afford large enough ones to be very useful anyway, they have the
potential to vent hydrogen when charged.  Of course hydrogen is
highly explosive, so you shouldn't charge any type of liquid 
electrolyte battery in an enclosed area, especially in a house.
Even sealed lead acids can vent if overcharged, but are the safest.
If the battery has any type of cap I'd never bring it indoors.
AGM batteries (absorbed gas matte, commonly mistaken for gell
Cells) are also fairly safe but can vent as well.  A huge mistake
Many people make is placing these in a room or even a closet with
A cheap auto type charger and leaving them on float.  The charger
Is very likely to cause enough spark from switches or relays etc
That could ignite the explosive vapors.

6) If you need high current, like for larger HF rigs or
big amps, don't use deep cycle batteries!  They aren't designed
for high current demands.  A plain old starting battery is.  Also,
beware of cheap deep cycle or combo batteries sold in places like
Wal-Mart, Costco or Sam's Club.  They usually don't last long because
They're mostly poorly designed and constructed and can't really
Do all things they promise, like being a starting battery AND being
Good at prolonged deep drain/charge cycles.  You'd be amazed at
How many folks replace batteries far more often than necessary
Because they just use the wrong type or in the wrong application.

7) Many people believe just using a few batteries will be less
costly, but probably not in the long run.  Most folks rarely get
a very long life out of a batt simply because it's too much hassle
to use and treat them properly.  So they end up replacing them 2-3
times more frequently than they're rated, and this cost adds up, 
especially environmentally.  Generators and power supplies last
for many years, and are usually easily repairable to extend their
life even further.  Given the cost of a decent deep cycle or AGM/gel
battery, and how frequently you usually replace them, the math just
don't add up.

Just some things to think about.
BTW - if you want probably the best battery
For extended use, look into the type used in golf carts.
Called tractor or traction batteries.  You might
Even be able to scam a few old ones from a golf course
That has their own cart repairman on site.  They
Won't be 100% but probably will work quite well
At reduced levels, which are plenty for our purposes,
For at least a few years.  They have to pay to dispose of them,
So might be glad to give a few away!  But take a friend along
These suckers are heavy!

-----Original Message-----
From: aprssig-bounces at lists.tapr.org [mailto:aprssig-bounces at lists.tapr.org]
On Behalf Of Chris Rose
Sent: Saturday, January 01, 2005 10:22
To: TAPR APRS Mailing List
Subject: RE: [aprssig] Quieting Honda Generator (was) Portable Ops from
12vvia115 VAC

Running the 12V out to a battery like is suggested
would probably do the trick for those who have that
option.

If not, how about setting up a battery or bank of
batts to provide the isolation needed by running the
120V out from the generator to a battery charger then
to the battery(ies) to run the radios?  Our club has
done this at Field Day with success.  When running
that way it also provides a power supply for 30 amps
for those who can't spend money for same but can get a
charger and a battery for the 24 hours.  

Chris 
KB8UIH

--- Ray McKnight <shortsheep at worldnet.att.net> wrote:

> I've been doing a lot of generator research myself.
> Something interesting you might not be aware of, is
> That almost all of these smaller generators do not
> Operate in the traditional manner, producing 120vAC
> Directly by turning a generating coil.  The
> generators
> You are talking about actually produce 12vDC, then
> feed
> This to a DC-AC inverter to get 120vAC.  So the
> noise
> You are experiencing on the AC output is most likely
> due
> To the inverter, and I would suspect most of these
> inverters
> Are not true sine-wave inverters (the Honda
> 2000-watt seems
> To be though because it is marketed for use with
> "sensitive
> Electronic equipment").  I would suspect that many
> produce
> A modified square wave, and are therefore very
> likely to
> Cause problems with some types of equipment
> (especially
> Things requiring a good sine wave for timing
> purposes, and
> Some laptop power supplies don't seem to like it
> much either).
> If your generator has a 12vDC outlet (and isn't
> electric start!)
> It probably falls into this category.
> 
> For my money, I never operate any electronics
> directly off
> Generator power, I always have a UPS to protect it. 
> One way
> You might eliminate your "noise" is by trying a good
> UPS with
> Isolation or preferably even an "inline" UPS like
> used on 
> Computer servers which always supply AC from the
> UPS's inverter
> (which is a high-quality sine wave output).  But be
> aware that
> most small, consumer-grade UPS's offer no line
> isolation or filtering.
> 
> If you've got a scope, take a look at the power
> produced by the generator
> and you'll probably be surprised.  If you actually
> need or can easily use
> 12vDC, maybe you can just pull that off your Honda
> and eliminate its
> inverter problems altogether.  Just a thought.
> 
> -----Original Message-----
> From: aprssig-bounces at lists.tapr.org
> [mailto:aprssig-bounces at lists.tapr.org]
> On Behalf Of J. Gary Bender, WS5N
> Sent: Friday, December 31, 2004 17:06
> To: TAPR APRS Mailing List
> Subject: Re: [aprssig] Quieting Honda Generator
> (was) Portable Ops from
> 12vvia 115 VAC
> 
> For those following this sub-thread, I got a direct
> reply from Jim, W6RMK, 
> pointing me to:
>
http://www.dellroy.com/W4EF's-Ham-Radio-Page/Portable_Operation/EU2000i_
> Filter.htm
> 
> The article describes a common mode filter for the
> AC output that did 
> the trick with the 2 KW Honda generator.  Looks like
> the same problem I 
> am having with the EU1000.  The noise seems to be on
> the AC line but not 
> radiating from the generator.  I.e., unplug the AC
> cord and the noise 
> goes away.
> 
> I will also try using the generator's 12 VDC output
> directly to the 
> battery when I am hamming rather than plugging the
> camper into the 120 
> VAC output.

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