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RE: How long will it take to charge my battery?
"Why not invest in a nice 100A panel meter? Here's one for $20."
Sal,
I've installed these quite some time ago to monitor my coach batteries:
http://www.ecovantageenergy.com/catalog/items/item204.htm
http://store.solar-electric.com/mka-100-100.html
http://www.bestconverter.com/Voltminder_p_178.html
The meters are mounted right on the dash so I can also keep an eye on things while driving. The ammeter shows me when the alternator has the batteries topped up. The voltmeter tells me that A) I didn't forget to switch ON the coach battery switch so the refrig is operating, and B) that the boost relay that connects the coach and chassis batteries together is operating reliably. I recently had to change this to a silver alloy contact relay because Winnebago's stock relay was getting intermittent (probably corrosion on the contacts).
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pnichols
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11/03/09 11:42pm |
Tech Issues
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RE: What's the difference in a Heat Pump and an A/C?
There are also new state of the art air-to-air heat pumps for home installations that are effective under 30 degrees. Some of these can have electric heat strip boost or propane boost. At low outside temperatures their computerized controls choose pure heat pump mode, or pure propane mode, or pure electric heat strip mode, or a combination of two of the three - depending upon which mode is the most energy efficient.
They're probably using variable speed rotary compressors with perhaps two stages in series to accomplish this and their efficiency rating numbers are way superior to my 30 year old Carrier's. There's no reason other than "money" that RV air-to-air roof top heat pumps couldn't be offered in scaled down versions of these very efficient home units - with either heat strip or propane boost to deal with outside temperatures below 30 degrees.
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pnichols
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11/03/09 05:48pm |
Tech Issues
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RE: How long will it take to charge my battery?
"I have about 23 feet of 8 awg cable going from converter to the battery."
Sal,
As you probably know, the Parallax 7345 output lugs are specified to fit up to and including 2 awg cable. I'm really curious as to what current my 7345 would pump into my 200 AH AGM coach battery bank with the batteries down to 50% SOC and 8 feet of 2 awg cable between the 7345 and the batteries. I think I have it written down somewhere what cable drop I measured with the Winnebago stock 8 awg cable in place (about 8 feet) in parallel with a large battery jumper cable strand I ran in parallel to the stock 8 awg. I'll have to look it up. I'd prefer to have real data along with the equation's prediction.
I'm on somewhat of a mission to force/show/prove my 7345 to be "just fine" with my 200 AH AGM batteries. I'm reluctant to modify it's output feedback so as to rule out cable resistance cuz I prefer not to mess with the 7345 internals. Currently, with about 30 minutes of V10 idling alternator charging time through 7 feet of 6 awg cabling plus 2 hours of converter charging through 8 feet of 8 awg cabling I think I'm getting up to 90% SOC from around 50% SOC with the fast AGMs.
I can of course pick up another expensive 3-stage charger it I ever need it - but I want proof it's cost effective to do so. I have a sophisticated and pricey solid state switching 3-stage trolling motor charger but it's only 15 amps, but I can't really see any way of using it along with the 7345 to emulate a 60 amp 3-stage charger.
P.S. Don't be so hard on your 7345. After all, don't they set one back $150 to $180 new? I think it's notorious "charging problem" is merely one of speed (charge time) with dinosaur-technology wet cell LA batteries and too-small cable sizes. I'll bet the 7345 would have a different reputation if manufacturers had been installing them with 2 awg cabling all along. ;)
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pnichols
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11/03/09 05:37pm |
Tech Issues
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RE: What's the difference in a Heat Pump and an A/C?
".. there is NO REASON to have a Heat Strip on a Heat Pump since they all have either Hydronic or Furnace system on board for sub freezing temps."
If you have hookups or have a dry camp generator running .... why use either your own propane or excessive generator fuel? If temperatures are 40 degrees on up, an RV heat pump is the least expensive electrical way to heat since you are not making new heat. If for some unfortunate/emergency reason when dry camping in 40 degrees on up temperatures you are forced to get some heat into your RV for awhile using a generator, it will use less fuel powering a heat pump then it would by creating new heat from only a standard electric heater to get the same BTU's.
For marginally lower temperatures - say 35 to 40 degrees - getting some heat out of an RV's heat pump plus installed heat strips in it will STILL take less hookup or generator power than through only use of standard electrical heaters.
"The reason for a Electric heat coil on Home heat Pump systems is for Heat when it stays below freezing and the Heat Pump cannot get the BTU's of heat out of the air."
As I said, my home system has two heat strip stages. On the first stage the home is getting heated some by the heat pump and some by the first stage electrical heating elements. This is less expensive than no heat pump at all.
This reasoning also applies to an RV heat pump being supplemented/helped in the 35 to 40 degree range by 5000+ BTU's coming from it's heat strip.
"The Heat Pump mode puts out more heat."
Not in the 35 to 40 degree range - in heat pump mode you would get SOME BTU"s but not enough. Heat strips would provide 5000+ BTU's additional.
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pnichols
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11/03/09 02:38pm |
Tech Issues
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RE: What's the difference in a Heat Pump and an A/C?
"Heat pumps units will not accomodate a heat strip."
This MAY be true for some or all RV air conditioner/heat pump combinations - I'm not sure. We've had an air conditioner/heat pump unit (AKA an "air conditioner that can run in reverse") in our residence - as our ONLY source of cooling and heating - for over 30 years and it has two stages of heat strips thermostatically controlled to kick in one or both stages for BTU boost depending upon how low outside temperatures get such that it's air-to-air heat pump mode no longer can work well.
I see no reason why an RV air conditioner/heat pump unit couldn't also include heat strips - other than it would require two separate 15 amp circuits feeding the unit so as to run both the compressor (for heat pump processing) and 1500W heat strip (for boost) at the same time.
By the way using a 110V, 15 amp, powered air conditioner/heat pump in an RV invalidates the axiom many quote to the affect that "1500 watts provides about 5000 BTU's of heat and there is no way around it". This statement is only true when using electrical power to create new heat. A heat pump can provide well beyond 5000 BTU's of heat to an RV's inderior from it's ~1500 watt 110V input .... because it merely transfers existing heat from the outside into the interior .... it does not create new heat. For situations where it's not super cold outside (below about ~35-40 degrees), it's a far more efficient use of (the Earth's) resources to heat your rig with a heat pump (and it's heat strips not on) instead of with a standard electric heater.
That's assuming you can get the warm air from the heat pump circulated down low in your rig - which is difficult with a ceiling mounted and ducted air conditioner/heat pump. If this problem is dealt with adequately, then it seems to me that an RV with an air conditioner/heat pump with heat strips - plus a conventional propane furnace - would indeed be a rig with a very versatile and flexible setup for interior temperature (and humidity) control.
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pnichols
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11/03/09 11:55am |
Tech Issues
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RE: 2008 E450 front hitch
Bill,
Thanks for those excellent links!
I've been looking for a front hitch to use for carrying a small scooter on our Itasca 24 foot Class C.
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pnichols
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11/03/09 11:22am |
Class C Motorhomes
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RE: How long will it take to charge my battery?
"Of couse can go much longer without running the 3.4A/40 watt/12v furnace fan."
I'm curious as to what kind of furnace you have. I thought most RV propane furnace blowers use more than 3.4A ... more like 6-7 amps. Or did you mean an average of 3.4A per hour because it's only ON an average of one half the time when heating your rig?
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pnichols
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11/02/09 08:02pm |
Tech Issues
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RE: Generator Question
"And I wish the Honda 650 was still on the market."
Floyd, they still are and here's an example:
http://phoenix.craigslist.org/evl/for/1446876930.html
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pnichols
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11/01/09 11:34pm |
Tech Issues
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RE: Time For New Batteries --> 12 volt vs 6 Volt ???
Paul,
RV batteries aren't rocket science if you keep the most important thing in mind:
Always buy a battery, whether it be 6V or 12V, that is labeled and advertised to be for only DEEP CYCLE use.
After this, pay as much as you can afford to get quality and then take care of it properly.
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pnichols
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11/01/09 04:31pm |
Tech Issues
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RE: onan sine wave?
"....but after the generator starts the UPS doesn't recognize the generator."
Now that is strange. I wonder if this is a grounding anamoly in a UPS with respect to where the ground pronge in a motorhome's 110V receptacle winds up with shore power versus generator power?
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pnichols
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11/01/09 04:24pm |
Tech Issues
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RE: dead outlets
Note that with some GFI outlets if they every trip from a fault they will never reset again so you have to replace them.
The Leviton GFI in my rig is this type. It will reset of course whenever you are "testing" it but if you, say, somehow get it wet so it trips .... you're out of luck and have to buy a new one. Leviton calls this a "new feature" of their GFI's. Very frustrating until you figure this out about your "supposedly good" GFI - I know from experience. (Can be expensive too at maybe $15 each - plus your time to install another one.)
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pnichols
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11/01/09 04:16pm |
Class C Motorhomes
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RE: Generator Question
"I would love to know what kind of special spark plug you have that quiets down the generator. What makes it special and where can I get one!"
Here's the special plug I switched to in both my portable Honda camping generator and my motorhome's 4KW built-in Onan generator:
http://www.e3sparkplugs.com/
Ater reading all about the research, engineering, and personal user testimonials concerning this plug, I decided to give them a try in our camping generators. Both generators seem to run smoother, quieter, and less burdened sounding. I have not made any precise gas consumption measurements yet, if ever ... but I figure that gas consumption just about has to be reduced a bit if the generators sound less burdened and smoother.
I just wrote down the numbers off the stock plugs that were in the two generators and took them into a automotive parts store that sold E3 spark plugs and then purchased the correct E3 plug as indicated on the E3 cross-reference chart.
Although these plugs are available for most automotive engine applications, they seem to be most popular for small engines such as ATV, motorcycle, snowmobile, etc..
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pnichols
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11/01/09 03:54pm |
Tech Issues
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RE: Voltage reading at charger/convertor and at battery
Sal, a few posts above you stated this: "I used that method to determine that my battery disconnect solenoid had very high resistance. I didn't activate the solenoid for over a year and the contacts corroded a little bit. After flipping the solenoid on/off a few times the contacts got a lot better. But still, I didn't like the voltage drop and removed the solenoid."
A bit off topic, but you might want to replace your battery disconnect solenoid with this rugged silver alloy contact solenoid:
http://shopping.murcal.com/Catalog/Bear-DC-Contactor-Family/114-1211-020;jsessionid=0a010c471f43e3c1a11ecc744d4b88c1f3921dcee21e.e3eSch4MaN4Re34Pa38Ta38Naxf0
I've put many hours of use on the solenoid above in the coach/chassis battery-combining "boost" application in my rig and it has performed very well ... reliable and ~no voltage drop because of the silver. I see no reason that this silver alloy contact solenoid couldn't also be used as the coach battery disconnect solenoid.
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pnichols
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10/31/09 11:56pm |
Tech Issues
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RE: Generator Question
"The 49db, on Eco-Throttle..."
That is the lowest dB noise spec I've seen on any portable generator, anywhere, at any time.
I think I've walked past/heard non-portable generators even quieter, but no portables quieter than the EU3000is.
Hats off to Honda on this one ... fantastic design/engineering job!
P.S. I own another model portable Honda (non-inverting) generator that runs at a constant 3600 RPM and has the quietest full speed noise spec that I've seen on any portable generator, anywhere, at any time. My Honda EX650 runs at a constant 3600 RPM at 54dB.
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pnichols
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10/31/09 02:10pm |
Tech Issues
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RE: White Rim Trail Drive Report
Pat,
Thanks for your great photo-documentary on this interesting trek!
From most of your photos it looks like our 24 foot Class C, driven very slowly, could do it too in dry weather. (I hear you laughing!!)
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pnichols
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10/31/09 12:18pm |
Public Lands, Boondocking and Dry Camping
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RE: How long will it take to charge my battery?
"V_bat + I_charge * (R_bat + R_line) < 13.2V"
Sal, this is a nice simple form of the equation and should help many in the forums to finally understand the importance of cabling resistance between charging equipment and batteries being made as low as possible.
P.S. #1: Your equation shows clearly that if I use AGM batteries ("R_bat" very low) and use about 8 feet of 2 guage cabling ("R_line" very low), I can probably save ~$200 or more by being able to continue using my stock Parallax 7345 converter for my 200 AH coach battery bank.
P.S. #2: Your equation also shows the importance of completing one's charging equipment's output feedback loop at the batteries (instead of on the equipment's PC board) so as to drive "R_line" to zero!
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pnichols
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10/31/09 12:07pm |
Tech Issues
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RE: Generator Question
I have a Classs C MH with a Onan 4KW Microquiet nicely installed by Winnebago in a compartment on the dinette side well away from the sleeping areas. The Onan sits well up inside the enclosure -> not with the bottom of it sticking 2-3 inches out under like on some rigs.
I use Mobil 1 Extended Performance synthetic in it and a special spark plug, which quiets it down even more over using the stock oil/plug. Even though it's spec is 67 dB, with Winnebago's install and the upgraded oil and plug, it's now quite acceptable on noise level, inside and out. We ran it all night recently in the hot/humid South, and we could not hear it inside over the air conditioner's fan. (We left a roof vent fan running on low, set on AIR IN, to ensure safety through use of positive interior air pressure.)
Of course it's louder than our little Honda portable we carry too, but the Onan is so powerful and ultra-convenient that we rarely mess with getting out and setting up the portable. We figure the Onan uses about 0.4 gallons of gasoline per hour out of the main chassis tank when runnning the A/C, so about 2 1/2 hours per gallon in this high power situation isn't too bad a tradeoff when needed for comfort. For charging our batteries/running hair dryers/etc., the Onan probably runs about 3 hours on one gallon. (The special spark plug we use also reduces fuel consumption on small engines.)
Note that even though inverter generators do throttle back and run slower at lower power loads thus using less fuel and making less noise ... an Onan, even though staying at 3600 rpm, does of course use less fuel and run quieter with lighter loading.
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pnichols
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10/31/09 11:36am |
Tech Issues
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RE: Motorhome Makers: Heads Up!
As far as the dinnette area is concerned, it would be VERY EASY to improve:
1. Make the seat and back sections of each very comfortable ... like a couch for comfort but of course just not as long. Most dinette seats/backs are not this way (comfortable) now.
2. Leave the table design so it can still go down flat between the seats and and seats/backs lay flat on it for the rare time you need an additional sleeping area. Must dinettes in RV's do this now.
3. Now for the good part that would make the dinette area SO MUCH more useful - have the table split in the middle and fold up against the window wall and held up with some kind of clip or strap arrangement. You would now have an area with too small opposing and comfortable (see 1. above) mini-couches for a lounge area. 1/2 of one, or both, dinette seats could even be designed so as to slide and tilt to form one or two recliners. You could even set up a portable recliner (La Fuma, etc.) the long way between the seats so at least one person could enjoy a full size lounge chair in small RVs. Small children could even play games on the carpeted floor area between the dinette seats when the table top temporarily folded up and held out of the way. I don't think any RV dinette area is designed this way now.
The dinette area would then be at least 5-way: Eating/table game area set up as a standard dinette. Additional bed. Small mini-lounge with the table folded out of the way. Additional carpeted floor space for small children, pets, etc. with the table folded out of the way. Additional room for temporary use of at least one full size lounge chair with the table folded out of the way.
You folks with large rigs probably could care less about this. But for us less-is-more folks, we could sure use the added flexibility
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pnichols
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10/30/09 07:01pm |
Class C Motorhomes
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RE: New Tires for 24' 2007 Winnebago View
Are you guys with cracks developing in your tire sidewalls keeping the tires covered as much as possible when parked? The sun can damage tires a lot when sitting around camping or in storage. Cheap insurance against sidewall cracking.
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pnichols
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10/30/09 10:43am |
Class C Motorhomes
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RE: holding tank heating
"I am going with 120v tank heaters and some 120v pipe trace cables."
This approach must be due to the type rig you have - TT or 5'er?.
For Class A/B/C motorhomes with means for keeping coach batteries up when on hookups, 12V tank heaters are of course no problem when 110V power is available. For the rare/unexpected occasion when you must rely on coach battery power, with 12V heaters you still have them available without the efficiency losses you get from inverters powering 120V heaters. I would always use the 12V heaters for the additional flexibility.
BTW, I assume that these tank heaters cycle on and off. So for instance, my two heaters consume 6 to 8 amps each when operating. If they are operating on a 1/3 duty cycle during the cold hours, this means they would consume 40 to 50 amp hours. Of course I have to have some means of topping up the batteries periodically (the next day, etc.) when using the 12V heaters.
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pnichols
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10/28/09 08:02pm |
Tech Issues
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