From: John De Armond
Subject: Re: what set off my smoke detector?
Date: Sun, 31 Oct 1999 00:36:52 EDT
Newsgroups: rec.outdoors.rv-travel,alt.rv

Dan Valleskey wrote:
> 
> Used our new (2 yr  old) Tioga 22E for the first time last w/e.  We
> found out the coach batterey doesn't hold much of a charge.  Around 3
> a.m. the smoke alarm went off, I woke up, it was cold, the furnace fan
> was barely blowing.  And something smelled smoky.

You didn't tell us what brand of furnace so we have to guess.  I'm
going to guess it is quite similar to the one in my
Itasca/Winnebago.  The smokey smell was your furnace burning with
too little air because the draft fan was undervoltaged.  Smoke
likely backed up and leaked into the compartment (not supposed to)
and tripped your smoke detector.  Looking at the schematic in the
manual, I see that it is a very simple spark direct ignition furnace
with a sail switch to prove draft before ignition.  No apparent
provision for undervoltage trip.  As the draft fan undersped from
low voltage, the sail switch should have tripped the furnace off. 
Looks like you have two things you need to check out.  First, find
out where the fumes leaked into the cabin.  Second, find out if your
furnace has a draft switch and if so, why it didn't work.  If it
does not have a draft switch, I'd be figuring out some sort of
undervoltage shutdown for the furnace, for operating without
sufficient draft is dangerous.  You might also look at where the
furnace exhaust is relative to windows and other sources of inside
air.  Mine is right above a window.  I know not to open that window
if the furnace is to be used.

> Woke up at 6, when the rest of the CG started to stir, we started the
> generator.  It would not turn over, I started the truck (trying to get
> some heat), than just for grins tried the generator again.  This time,
> turned over and started fine.  

The cross-connect relay that parallels the batteries so that they'll
charge off the vehicle alternator was energized when you cranked the
engine.  That let the generator crank from the vehicle battery.

> I got home, put the battery on my big charger, a fancy regulated one.
> All week, it hardly ever stops accepting a charge.  I am new to deep
> cycle batteries, but a car battery doing this, I would say is trashed.

Can't say.  Don't know anything about your charger.  The Group 27
deep cycle marine batteries I use on my lab's UPS take a full day to
charge on the regulated 10 amp charger.



> Is it possible I should not expect a coach battery to run the furnace
> through one night?

Only way to answer that question is to measure the actual current
draw.  Look on your house battery and determine the amp-hour
capacity.  Divide that by the total amp draw and you have
approximately how many hours the battery will last.  If your current
draw in amps is greater than one tenth the  amp-hour capacity, then
the life will be shorter than what you calculate because of the rate
effect.

I suspect things are working properly in your MH.  The simple
solution is to add a second house battery. I don't know what size
your Tioga is but in my little Itasca (ready-to-roll weight 7800
lbs), finding a spot for a second house battery was a trick.  I
finally figured out how to mount one under the skirting next to the
built-in propane tank in a fabricated battrey box.

Watch out for some of the other advice I've seen in this thread. 
Slapping five or six hundred pounds of golf cart batteries onto a
light weight chassis might cause interesting handling problems.  Or
make it have a permanent lean.  Or both.  And unless you plan on
trying to run everything in the house from an inverter, it would be
gross overkill.  A couple of deep discharge marine batteries will do
just fine.  Incidentally, and despite what some say, the group 27
batteries can be almost completely discharged with little to no
effect on life.  I have a number of them in service powering
portable neon signs that I rent out.  The solid state neon power
supply cuts off at 10 volts to protect everything from that last
dying gasp from the battery :-)  By 10 volts, the battery is pretty
much completely discharged.  I have at least a couple of Delco
Voyagers still in service that were bought in 1993.

My solution to the house battery life situation, beyond having two
house batteries, is to carry a tiny extra generator.  A gallon of
gasoline contains more energy than a thousand pounds of batteries
can store.  I have a little Honda EX350.  Weighs oh, 12 pounds or
so.  Makes 350 watts.  I put a power cord on my converter so I can
plug just the converter into the generator.  It won't run the
converter at full power but it will run the lights and the furnace. 
The generator will run all night on a tank of gas and is so quiet
you can't hear it a few feet away.  I just chain it to the back
bumper and let 'er run.  I only use this when I know I'm going to be
in one spot for more than a day.  Any less and the dual house
batteries do the trick.  

This generator was the first of Honda's inverter generators.  That
is, the engine drives a car-like alternator which then feeds a
synthesized 60 hz inverter.  The great advantage is that the engine
no longer needs to run at sync speed (1800 or 3600).  It need only
run fast enough to supply the load.  The EX350 has a high and low
speed switch.  On low speed it will make just a little under 150
watts and can hardly be heard running.  The newer Honda EU series
inverter generators appear to be more sophisticated in that they
vary their speed automatically in response to load.  And they are 4
stroke.  The EX350 is a 2 stroke.  I run it at 80:1 oil mix using
Honda's synthetic 2-stroke oil.  Essentially no visible smoke and it
smells OK.  

John

From: John De Armond
Subject: Re: Amperage and batteries
Date: Sat, 03 Jun 2000 20:46:46 EDT
Newsgroups: rec.outdoors.rv-travel

Nick Simicich wrote:
> 
> I'd appreciate it if someone would help me check my math.
> 
> I use a CPAP.  This CPAP has an option for a 12-24 volt cord, but it
> uses various amounts of power and my prescription is just below the
> level where they don't recommend the cord because the draw is too high
> - they recommend an inverter in that case.  With the 12 volt input the
> claim is 80 watts (6.66 amps) while with AC it is 800 ma at 120 volts,
> 400ma at 240 volts.  96 watts, or the same 8 amps through the inverter
> (according to phred).  I'll just use a small inverter to power the
> CPAP so if my prescription goes up I won't need to switch.

My dad uses one of those machines and he's never heard of that sort
of limitation.  I would tend to go with other advice given in this
thread and try it on 12 volts and see how it does.  

 
> 2.  The two SRM29's will fit in the existing battery space under the
> step.  I won't have to convert a compartment to battery use as I would
> if I went with a 4D or pair of golf cart batteries.

This battery is only 87.5 amp-hour (computing back from the reserve
capacity)  Is this really the largest battery you can get in that
space?  If at all possible, I'd look at something other than a
cranking/marine battery.  With a true deep discharge battery, you
can discharge much farther than you can one of these.  You might be
better off with smaller deep discharge batteries.  You can safely
take such a battery down to 10 volts with little impact on life.  I
know wild figures like "no more than 50%" get tossed around this
group and even by some manufacturers but 10 volts is the industry
standard.  Some, such as trojan, quote 80% but 10 volts is an easy
figure to work with.  Even if you do hypothetically knock a year off
the life, big deal!  At least for me, it's not the end of the
financial world to go out every few years and pay oh, $140 for a
pair of marine batteries.

Something else to think about.  The two batteries don't have to be
next to each other!  When I point this out, many people get a really
surprised look as the mental light bulb comes on :-)  You didn't say
what kind of RV you have but it sounds like a motorhome.  In my MH,
I found a place to put the second RV battery between the radiator
and front grille.  I fabricated a little marine plywood platform for
the battery box to sit on and then bolted the box to the platform. 
The other battery resides in the stock position.  I now have almost
300 A-H on the house side and another 135 a-h in the cranking
battery.  I use the same deep discharge battery for cranking.
Perhaps finding some other place on your rig for another battery
would solve the problem.

I'm the kind of person who probably spends too much time figuring
out all possible ways things can go wrong and then trying to do
something about them.  If I had to use such a machine, I'd load my
rig up with enough power that there would be no chance of running
out of power.  Then I could worry about something else. :-)

A little of that philosophy might help here.  The possibility of
your machine failing during the night is obviously bothering you so
why not eliminate the possibility with a little overkill?  Overkill
your power situation a bit and then be able to go to sleep and not
have to worry about your machine running all night.

Might I make one other suggestion?  These new Honda inverter
generators are so quiet that they couldn't bother anyone except
those LOOKING to be bothered.  I have run my EX-350 inside a
cardboard box (with vent holes cut) at craft shows where generators
were banned and no one even realized it was there.  Mine's a
2-stroke.  The new EU generators are 4 stroke and even quieter. 
What's really nice is that with a small load such as your CPAP, the
engine is spooled down to slower speeds.  Even less noise.  Why
don't you consider one of the small EU generators, and just set it
under your rig at night with a chain around it to keep it from
growing legs?  Put it in a box if you need it to be even quieter. 
If you hook it up to a battery charger and run the CPAP on 12 volts,
you have a very nice UPS for your machine.

John

From: John De Armond
Subject: Re: Amperage and batteries
Date: Mon, 05 Jun 2000 21:59:27 EDT
Newsgroups: rec.outdoors.rv-travel

Nick Simicich wrote:
> 
> On Sat, 03 Jun 2000 20:46:45 -0400, Neon John
> <johngdNOSPAM@bellsouth.net> wrote:
> 
> >Nick Simicich wrote:
> 
> >> 2.  The two SRM29's will fit in the existing battery space under the
> >> step.  I won't have to convert a compartment to battery use as I would
> >> if I went with a 4D or pair of golf cart batteries.
> 
> >This battery is only 87.5 amp-hour (computing back from the reserve
> >capacity)
> 
> According to Interstate (in their deep cycle FAQ), you get AH from RC
> by multiplying by 0.6.
> 
> The SRM29s are 210 minutes RC. That means 126 AH, according to
> Interstate.  So I'll have 250 AH total.  Do you have a different
> formula?

Boy, I hope I'm not brain farting on this one.  I just used the
definition of reserve capacity - the number of minutes the battery
can supply a 25 amp load.  210 minutes * 25 amp = 5,250
amp-minutes.  Divid by 60 to get amp-hours = 87.5.  I don't know
where the difference is unless they're defining amp-hours at a C/20
discharge rate.  I've seen this value creep in lately instead of the
historical C/10 discharge rate.  C/20 will produce a bigger number
for amp-hours (perkut exponent at work again) but there will be no
more actual capacity for a given discharge rate. 

> 
> >  Is this really the largest battery you can get in that
> >space?  If at all possible, I'd look at something other than a
> >cranking/marine battery.
> 
> The next size up is a 4D, at least on the "Interstate" site.  The
> problem with a 4D is that it is a 120 LB battery, and it is 234 AH.
> 
> I don't know of any form factors between 29 and 4D.  I'm not that
> experienced here, though.

I'm not either really, at least not in knowing what the group
numbers means.  I took a kinda backwards approach.  I found the
largest batteries I could buy off the shelf and then figured out
where to mount 'em :-)  The Trojans and similar ilk are nice but I
wanted something that I could run down to the local wallyworld or
Autozone and replace rather than having to order and wait. 
Double-nice when you're on a trip and the batteries tube!

> I have back problems.  With careful bracing, thinking about position
> every second, I might be able to lift 61 lbs, I've done it.  I'd not
> be able to lift 120 lbs.  This means that I might be able to deal with
> a problem with the 29's, but I won't be able to deal with a problem
> with the 4D's.

Same boat here.  Bad back.  I just went in the restaurant, grabbed
the first stout employee I could find, dragged him by the ear out to
the RV and said "lift!".  Works every time :-)  I figured I'd only
have to have them lifted every couple of years or so, so I made the
tradeoff toward capacity.

IF I didn't have a  handy employee, I'd probably get out my engine
lift or a block and tackle or corral a friend :-).  

> 
> Now, I was wrong, I could probably fit two  6V golf cart batteries
> into this space.  Part of the issue here is that I already use the
> SRM29's in another application so this gives me some backup.  If I
> weren't, I'd probably go for the pair of U2400's for 240 AH with no
> cranking spec (and, most likely solid lead plates).
> 
> The suggestion about jumpers off of the cart is a good one.
> 
> I guess I really wonder, after all this, why motorhomes are 12V
> instead of 24V.  If they made them 24V, they could really screw us on
> the accessories, and wire them with lighter wire.  :-)

I like that idea.  I'm currently building a small 2 wheeled scooter
(like the Zappy, only more rugged) so that I can more comfortably
work large trade shows, hotrod shows and the like.  I'm using 2
12/20 ah gell cell batteries that I bought at the Daytona hotrod
show plus a 24 volt high efficiency servo motor.  quick charging is
going to be a pain in the ass since I'll have to carry a battery
charger.

For this and a lot of other reasons, I almost converted my MH's
house system to 24 volts.  The alternators are available, as are
inverters and converters.  Ditto lighting, though I was also
considering running the lighting off a small inverter.   I finally
chickened out - for this rig.

Since some big rigs and a lot of heavy equipment already use 24
volts, there's no hardware reason to not switch.  I suspect that
it's a market thing.  Your average Joe Dumbass would probably freak
when he heard that the electrical system used a different voltage
than his old pickemup truck!

 
> However, unless this Honda generator is less than 60 lbs, again, I
> don't want to move it every night.  I'm more likely to sit up and read
> with a itty bitty book light and sleep when I can plug in than move
> something heavy in and out of a MH compartment.

Honda lists the EU1000 at 29 lbs.  They make another inverter
generator that they for some reason don't list with the EUs.  It's
the EX700.  Appears to be the grown-up brother of my EX-350 and has
a 4 stroke instead of a 2 stroke engine.  Though they don't say so,
I suspect that this is a square wave inverter, as is on the EX-350. 
In any event, this unit is listed as weighing 26 lbs.

> 
> By the way, John, it has been years since we have exchanged posts.
> Good to see that you are still around, I enjoyed it then and I do now.
> 
> And I appreciate everyone's comments about this.

Hey, Nick.  I hadn't even noticed who I was replying to.  Long time,
no chat.  I went off the net in 93 or so and just came back up last
year.  Bought my first RV in a LONG time last year and have only
missed one weekend in it since.  Glad to see you're still kicking
around.

John

From: John De Armond
Subject: Re: Amperage and batteries
Date: Tue, 06 Jun 2000 04:00:38 EDT
Newsgroups: rec.outdoors.rv-travel

Nick Simicich wrote:

> Yep.  They have a bunch of numbers for discharge rates on their site
> and use C/20 for Amp hours.  It is also clear that it is not linear.
> 
> 21,4 hours at 5 amps = 107AH.
> 9.4 hours at 10 amps = 94 AH.
> 5.9 hours at 15 amps = 88.5 AH.
> 4.3 hours at 20 amps = 86 AH..
> 3.2 hours at 25 amps = 80 AH.
> 
> http://www.interstatebatteries.com/battery_care/mrv/ah.htm
> 
> Then again, these numbers match neither their claimed reserve capacity
> at 25 amps,  nor the multiply by .6 to get C/20 discharge.
> 
> My suspicions is that this is a more accurate statement of capacity
> than the optimistic numbers on the side of the battery.  So this means
> that if all I'm plugging in is the CPAP, I can get a night out of one
> battery, and if the heater draws no more than 5 amps, I'll get a night
> out of two batteries.  Or better since the draw is halved because I
> will parallel two batteries.

IF you wanted to actually measure the capacity of the battery of
interest, it can be easily done using a load (a 100 watt halogen
lamp draws about the same power as your CPAP), a 12 hour meter (the
one from your RV generator would do in a pinch) and a 12 volt coil
relay.

here's the drill.  Hook the hour meter and load in parallel.  Hook
these to the battery in series with a NO contact on the relay.  Hook
the relay coil in parallel with the loads through the NO contact. To
run the test, charge the battery, manually push the relay contacts
shut (the relay will latch) and let it run. Somewhere below 12 volts
the relay will drop out, the loads will be deenergized and the hour
meter will read the number of hours the load ran.  The relay's
dropout point isn't defined but since the voltage very quickly drops
at the end of the battery's life, this isn't a big deal for a
one-time test.  buy a candidate battery from a place with a
money-back guarantee and you won't even be out the cost of the
battery if it doesn't work.

You're going through the same thing I did when I had to size
batteries for unattended radio sites that we had to guarantee to
operate a set number of hours after power failure.  I found that the
rated AH is only approximate.  I used a similar test rig to
determine battery capacity, the only difference being a simple
transistor/zener voltage comparator.

> 
> On this table, the U2200's and larger look really good.    But, as I
> noted in the other post, I have to start the generator.
> 
>  >I'm not either really, at least not in knowing what the group
> >numbers means.  I took a kinda backwards approach.  I found the
> >largest batteries I could buy off the shelf and then figured out
> >where to mount 'em :-)  The Trojans and similar ilk are nice but I
> >wanted something that I could run down to the local wallyworld or
> >Autozone and replace rather than having to order and wait.
> >Double-nice when you're on a trip and the batteries tube!
> 
> Did this end you up with 4D's?

I got the biggest deep discharge battery Wallyworld was selling at
the time.  Don't remember the designation.

> >I like that idea.  I'm currently building a small 2 wheeled scooter
> >(like the Zappy, only more rugged) so that I can more comfortably
> >work large trade shows, hotrod shows and the like.  I'm using 2
> >12/20 ah gell cell batteries that I bought at the Daytona hotrod
> >show plus a 24 volt high efficiency servo motor.  quick charging is
> >going to be a pain in the ass since I'll have to carry a battery
> >charger.
> 
> I think that pretty much the lions share of mobility scooters use 24
> volt motors and two Gel or Wet cells (mostly gels), 24 volt lighting
> and headlamps if equipped, etc.  Then again, these are 3-4 wheeled
> scooters so they would probably be too stable for you. :-)  But you
> might be able to find parts if you do not have them handy.  Also, they
> usually have built in chargers, and they have a finite life.  If I was
> looking for a 24 volt charger, I'd talk to the local people who do
> mobility scooters in my area about junk parts, they might have a
> charger that will charge these gel cells without killing them.

Good to know.  Thanks.  I didn't realize that the smaller units were
also 24 volts.  That's a major failing of the Zappy scooter - it's
12 volt powered.  That and the fact that the frame dragged the
ground when I stepped on it :-)

> >Honda lists the EU1000 at 29 lbs.  They make another inverter
> >generator that they for some reason don't list with the EUs.  It's
> >the EX700.  Appears to be the grown-up brother of my EX-350 and has
> >a 4 stroke instead of a 2 stroke engine.  Though they don't say so,
> >I suspect that this is a square wave inverter, as is on the EX-350.
> >In any event, this unit is listed as weighing 26 lbs.
> 
> OK, I'm going to have to look at this.  Thanks.

I've ordered a GX-31 honda engine (1.5 hp, about 7 lbs 4-stroke) and
am going to revisit my cordless battery charger again.  I believe I
can design one that will weigh in under 15 lbs and put out at least
60 amps. I have some new ideas on this.  Meanwhile, you might
consider making a simple version.  The engine and a small alternator
from a compact car (I've tested alternators from toyotas and Geo
metros) plus either a welded frame or a wooden frame will make a
nice little generator to fast charge your batteries.

I offer this an alternative to running a 120 volt generator all the
time.   

From: John De Armond
Subject: Re: best batties
Date: Tue, 06 Jun 2000 03:40:22 EDT
Newsgroups: rec.outdoors.rv-travel

Peyerl Fritz wrote:
> 
> Dear William
> 
> Sorry to correct you but Deep Cycle batteries are designed for low currant
> discharge and NOT for starting batteries.

Shhhh.  don't tell 'em.  Then the deep discharge batteries in all my
vehicles might get some radical ideas and quit working.

As long as the secret doesn't get out, they work just fine as
cranking batteries.


John

From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: new batteries this spring.
Date: Sun, 28 Jan 2001 18:02:45 -0500

ben hogland wrote:

> "Ben Franklin VI" <f5anklin@aol.com> wrote in message
> news:20010128170424.22458.00002976@ng-mq1.aol.com...
>
> > A digital voltmeter is a good idea for keeping track of your batteries
> > condition.
>
> A Hydrometer is a better way to keep track of the batteries. A voltmeter can
> hide the true state of charge. An added plus? A hydrometer is much cheaper
> then a volt meter.

Let's see.  $8.50 for my nice temperature compensated hydrometer at
NAPA.  $10 for my universal chinese throwaway digital volt meter I
keep in the RV.  Decisions, decisions.  Do I eat or do I splurge....

Anyway, I suggest both.  The DVM is very useful when dry camping to
see when it's time to recharge.  The hygrometer lags too far behind
the actual state of charge to be useful.  OTOH, the hydrometer can
tell you when it time to equalize or if there's a charging system
problem.

I've discovered that when fast charging, the specific gravity lags
behind the actual charge by many hours.  Even after vigorous
bubbling, when the 3 stage charger is finished charging, the SG
still shows firmly in the "discharge" region.  Wait several hours
(usually overnight) with no further charging and the SG comes up to
where it should be.  I suspect that the really good acid that's
released by the charge cycle stays trapped in the plate area and
only slowly diffuses out.

To the original question,  I recommend Stowaway batteries (Sam's) if
you're on a budget or Trojan if you're not.  Trojan is making the
Stowaway batteries now according to the label. Whether they're of
the same quality, who knows.   I have decades of good experience
with Stowaways.  Just replaced a set on the computer room UPS last
year that I had installed in 92.

I also suggest that if it is at all possible, install two of the
largest batteries you can fit in.  Even though it took a LOT of
work, that's what I did on my rig.  I had to partially remove the
front grille and hood latch support and fabricate a platform to set
the second battery right behind the grill and in front of and a bit
below the radiator.  Worth every second of the effort.  Before, with
wifey's electric blanket and the gas furnace going and a reasonable
amount of other activities with the lights on, we could just barely
make it through a long night and only then by deeply discharging the
1 Group 27 battery the rig was originally equipped with.  Now we can
be lavish for a 1-nighter (TV on the inverter, etc) and can make it
through a 2-nighter with only a little care.

John

From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: new batteries this spring.
Date: Sun, 28 Jan 2001 23:58:22 -0500

ben hogland wrote:

> > Let's see.  $8.50 for my nice temperature compensated hydrometer at
> > NAPA.  $10 for my universal chinese throwaway digital volt meter I
> > keep in the RV.  Decisions, decisions.  Do I eat or do I splurge....
>
> Wow, you know where to shop.. I haven't seen a cheap "digital" volt meter
> for 10 bucks.. Then again, I haven't looked because I have an expensive
> Fluke DMM which has lasted for years way beyond what a cheap volt meter
> would last. Call me frugal. <g>

Well, after a recent selling frenzy on Ebay, I'm down to about 8 or
9 flukes including 3 8800A's (5.5 digit) and a Beckman (true RMS -
nice but slow).  However, to get beaten around in my RV, I don't
think so.  The $10 special works just fine.  Yeah, it came with
cheap lead and the contacts are brass instead of gold plated but my
Fluke meter calibrator says it's right on on volts and amps and my
L&N standard resistor says the ohmmeter is spot on too.  And let's
face it, at almost $400, I can buy, use and throw away 30 or 40 of
the chinese meters before I break even on another Fluke 88.

As to buying opportunities, I got mine at the local flea market.
You can get one anywhere you find those guys selling the cheap
chinese tools.  Northern, Harbor Freight and other such outfits also
sell 'em.

John