Ok, so I'm tearing into the 2017 Classic 30' and figured it was a good time to take some real data. I've seen a lot of numbers tossed around for this and that here on the forum. I make no claim that every trailer is set up the same....
Inverter back feed current 100 ma
House line ( propane det.) 73 ma
Rest of world ( in store mode). 41 ma
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Total parasitic current. 214 ma
All numbers at 12.6v with a good meter.
So what's that mean?
In 24 hours, you will dump 5.14 amp hours out of your batteries. In a week, you dump 35.95. In a month you would burn of 154.08 AH.
Depending on what you read, your lead acid batteries might dump 10% of capacity in a month. Some manufacturers claim more, others less. On a 200 AH pair of AGM's that would be 20 AH. Net would be a loss of 174 AH.
Since you ... errr .... may have 100 AH to use out of your AGM's storage for a month is a really bad idea. Since this *is* in the store mode there's not much you can do about it on a stock trailer.
If you re-wire and take out all but the house line ( = propane detector +?? ) you get: 1.87 AH / day , 13.01 AH / week , and 56.16 AH / mo. Add the 56 per month to the 20 self discharge and you are at 76 AH per month. That's inside the 100 AH number, but not comfortably so. Your battery may or may not be fully charged.... Even with just LP detect hooked up, a month in storage is a bit of a risk. Hooking up so things work this way does require a bit of effort.
One *could* observe that parked in the back of a storage lot with nobody closer than 10 miles away ... the propane detect can go off and it will do no good at all. Working that out is up to you. I have walked past beeping trailers on the storage lot multiple times ... who knows what that beep means on that trailer ....
The "rest of the world" number is a bit of a mystery at this point. You get 29 AH per month loss down that line. I may investigate that further.
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So what about other batteries? I'd bet that the current at 14V will be the same as at 12V. The gizmos likely are running on the other side of linear regulators. You will dump the same amp hours into the loads with any battery system. Your "time to destruction" will improve with bigger batteries, but you still will dump a lot of energy.
One could also note that the factory solar package will put in 80AH a day on a good day. Even if you only get 10% of that, you are doing fine.
The data above is all done with the factory solar gizmo stored in a round bin along with a bunch of empty beer cans . If it has a back feed current, that's not in the numbers. Also the converter on the trailer is not stock. I don't believe that throws things off much at all.
A bit later I'll get to some real numbers on the Classic ( and it's FireFly panels ) pulls once it's out of the store mode.... I'm quite sure they will make any of the stuff above look very trivial.
Quick answer to the propane question - not everybody is as careful as they should be about turning off propane ... Also, if you are going to use an automatic cutoff, putting the propane detector on the auto gizmo may not be a real good idea.
Some more numbers:
Part of the parasitic numbers will be the "back feed" into your solar charge converter. The Victron unit I'm putting it measures about 28 ma. That comes out to 0.67 AH / day, 4.7 AH / week, and 20 AH per month. I have no idea how that compares to the stock unit.
I also have a DC/DC converter to charge off of the truck. It has a back feed current of < 0.5 ma. The BMV 712 is in the same vicinity. Neither one is worth worrying about.
Now I turn on the trailer and take some more data. Again, this is a Classic with all the FireFly stuff.
Use switch on and everything off = 1A ( it bobbles a bit )
Turn off the LED's on the control panels and it drops *maybe* 0.1 A
Fan running on low is 1.3A, medium is 1.8 and high is 2.8A
Main cabin lights come in at 1.2A. most of the smaller stuff is in the 0.25 to 0.35A range.
Fridge at turn on pulls 0.8A
Bottom line seems to be that the FireFly does pull power and that's not ideal. It does not pull an insane amount. The 3A numbers that get tossed around are not correct. If you get 80AH a day off of the factory solar panels and never turn on the inverter .... you can go for quite a while, even in a Classic. ( yes, the internet is also missing .... shucks ....)
Regarding the propane detector, some I have seen claim that if power is removed, the detector accumulates dirt/dust, etc. that causes false alarms. Apparently there is some mechanism to keep the detector clean and maybe that is where the parasitic power goes. My trailer has the manual cutoff switch and everything is now on the trailer side - nothing on the battery side. When I cut it off, it is off! There is virtually no risk of my leaving the detector powered off, as the tongue jack, which is required to hook up, is also controlled by the switch.
I wired my Safari 25 the same way. I have never had a problem with detector false alarms after a month or more of power off. I have also tested the detector by wafting a little propane from a torch to it and it works. Boy does it work!
Al
__________________
“You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO WBCCI 1322
2002 Classic 30 Slideout -S/OS #004
2013 Dodge 2500 Laramie 4x4 Megacab Cummins
Was reconciling some numbers to go with my Zamp lite 120W panel to boondock...(attached) somewhat difficult to find all the device specs...on current draw; so guesstimated. The portable panel gives me some flexibility to orient to sun path...but sun needs to shine to be “sustainable”.. Did change out converter on 2017 23FB...and getting ready to add Group 27 batteries for a bit more capacity (and better storage solution with 5W solar maintainer)....bottom line - extra blanket better than furnace fan; turn pump switch off when not using water; open those big AS windows for nat vent ...rather than fans...lighting...use rheostat (maybe...)...to manage demand side....will see. Did find a DC clamp on ammeter $70 to check my guesses on those circuits at panel ...will see where this pilot study goes...
I very much understand the issue of "sort of guessing" at some of the numbers". That's one of the reasons I grabbed a good DVM to do the readings. That's not to say the numbers are perfect, just that I wanted the meter to not be the limiting part of the process.
One thing that gets left out of a lot of the solar -> battery stuff: There's this wonderful problem with lead acid batteries. You charge 20% more than you get back. It *before* you figure in wire loss and converter efficiency. If you take a look at the programming on a battery monitor you will find it under the "Peukert effect". It's been around since ... err ... the 1880's ( yikes ).
I very much understand the issue of "sort of guessing" at some of the numbers". That's one of the reasons I grabbed a good DVM to do the readings. That's not to say the numbers are perfect, just that I wanted the meter to not be the limiting part of the process.
One thing that gets left out of a lot of the solar -> battery stuff: There's this wonderful problem with lead acid batteries. You charge 20% more than you get back. It *before* you figure in wire loss and converter efficiency. If you take a look at the programming on a battery monitor you will find it under the "Peukert effect". It's been around since ... err ... the 1880's ( yikes ).
Agree to measure is to know; Ah yes with some help...Georg Ohm, Alessandro Volta...1830’s....Andre Ampere 1770’s ..with Georg’s help...R=V/I; a bit like a moving target...So for the AS electrical experts ...if R constant (device - exception LED) then as battery voltage drops - current drops - power drops...so my amp draw estimates are avg between 12.2-12.8V???? ...not to diminish James Watt....as he was in the same time frame to figure all this stuff out for us....
I very much understand the issue of "sort of guessing" at some of the numbers". That's one of the reasons I grabbed a good DVM to do the readings. That's not to say the numbers are perfect, just that I wanted the meter to not be the limiting part of the process.
One thing that gets left out of a lot of the solar -> battery stuff: There's this wonderful problem with lead acid batteries. You charge 20% more than you get back. It *before* you figure in wire loss and converter efficiency. If you take a look at the programming on a battery monitor you will find it under the "Peukert effect". It's been around since ... err ... the 1880's ( yikes ).
Agree to measure is to know; Ah yes with some help...Georg Ohm, Alessandro Volta...1830’s....Andre Ampere 1770’s ..with Georg’s help...R=V/I; a bit like a moving target...So for the AS electrical experts ...if R constant (device - exception LED) then as battery voltage drops - current drops - power drops...so my amp draw estimates are avg between 12.2-12.8V???? ...not to diminish James Watt....as he was in the same time frame to figure all this stuff out for us....
Hi
There is a lot of stuff on a modern trailer that behaves as a non-resistive load. Anything with a switching regulator in it ( control boards ...) will look like a negative resistance ( constant power load). The stuff with linear regulation will behave as a constant current load. About the only thing that will stay resistive are motors. Even there, the motor will run faster at the higher voltage. On a water pump that means time to pressure is less. ( = you are back to constant power). In the case of a thermostatic fan, you get the same thing *if* it is throttling. Even boiling a pot of water in the microwave is a constant power sort of thing.
So what's that all mean? It suggests that voltage variation isn't as big a deal as you might think at first ..... Of course with lithium's the voltage doesn't change much so it's even less of a variable.
There is a lot of stuff on a modern trailer that behaves as a non-resistive load. Anything with a switching regulator in it ( control boards ...) will look like a negative resistance ( constant power load). The stuff with linear regulation will behave as a constant current load. About the only thing that will stay resistive are motors. Even there, the motor will run faster at the higher voltage. On a water pump that means time to pressure is less. ( = you are back to constant power). In the case of a thermostatic fan, you get the same thing *if* it is throttling. Even boiling a pot of water in the microwave is a constant power sort of thing.
So what's that all mean? It suggests that voltage variation isn't as big a deal as you might think at first ..... Of course with lithium's the voltage doesn't change much so it's even less of a variable.
Bob
Thanks, got it.... make sense - fewer resistive loads... good points on what really are moving targets; if I just keep an eye on my demand habits... should be just fine.
Now I turn on the trailer and take some more data. Again, this is a Classic with all the FireFly stuff.
Use switch on and everything off = 1A ( it bobbles a bit )
Turn off the LED's on the control panels and it drops *maybe* 0.1 A
Fan running on low is 1.3A, medium is 1.8 and high is 2.8A
Main cabin lights come in at 1.2A. most of the smaller stuff is in the 0.25 to 0.35A range.
Fridge at turn on pulls 0.8A
Bob
Excellent data, Bob, thanks. Do you have any data on ALDE current consumption while off grid while in water and radiant heat mode? I’d assume that the loads would be the controller and circulating pumps, and in any case, a lot less than an Atwood furnace fan running 20 minutes per hour all night....
I’d pull my own DVM out and make the measurement if I weren’t on the road :-)
I *should* check the Alde while I have everything torn apart. Right now I still have anit-freeze in the system so ... not so much. If I get brave and flush everything I may give it a try. I would like to know how much the Alde control board pulls. The rest of it would be the pump and the fan on the propane burner. From what others have said, the draw there is pretty low. One note - the pump on the system is variable speed. My guess is that a proper test would look at current vs speed setting .... hmmm ... more to do
Something like the "ESI 301M Fuse Buddy Mini DMM Adapter" (on Amazon) makes this all pretty easy, as then you can just measure every circuit at the fuse box. Swap the fuse with it and your multimeter hooked up, and then go around switching things on/off and putting them into a sheet.
In my case I found that my LED ceiling bulbs use 0.24amp each, so if I have 4 on it is 1amp. My Fantastic fan uses 0.9A/1.2A/1.6A, the TV booster seems to draw 1.3mA. I didn't get a chance to try to measure the water pump or other pieces, as those are less elective. My setup is '11 Sport 22, so its all very basic and no fancy digital anything. I am putting kill switches on the radio and any 12V powered USB ports that I add will also have them, or I may just stick with 12V power sockets that can just be unplugged.
I have read that switching to a PWM controller for the Fantastic fan reduces power draw, which is intriguing along with more speed options.
Insane as it may seem, the Classic really doesn't have any fuses. It's all thermal breakers.
I should have run the math for the LED lights. I know how many are on each switch .... why would anybody else ... The small LED fixtures pull about 80 ma each. Since they are dimmable, that's at whatever setting the dimmer defaults to. ( Yes another thing to investigate )
Was reconciling some numbers to go with my Zamp lite 120W panel to boondock...(attached) somewhat difficult to find all the device specs...on current draw; so guesstimated. The portable panel gives me some flexibility to orient to sun path...but sun needs to shine to be “sustainable”.. Did change out converter on 2017 23FB...and getting ready to add Group 27 batteries for a bit more capacity (and better storage solution with 5W solar maintainer)....bottom line - extra blanket better than furnace fan; turn pump switch off when not using water; open those big AS windows for nat vent ...rather than fans...lighting...use rheostat (maybe...)...to manage demand side....will see. Did find a DC clamp on ammeter $70 to check my guesses on those circuits at panel ...will see where this pilot study goes...
I make some measurement of parasitic loads on my 2011 23FB.
Each day there is 6.8 Ah-Hre load on the batteries.
When I purchase my travel trailer, the dealer (CanAm) install a 95 watts solar panel with a 4 stages controller.
For boondocking autonomy I purchase a portable 90 watts panel and with these panel and the OEM original Group 24 Interstate batteries and additional portable 100Ah AGM battery, I am OK for 7 days without restriction consumption. Including TV watching, DVD reading for my grand children and even a hair blower for my wife hook up to the 600w pure sine wave inverter.
See my calculation attached.
Michel
Insane as it may seem, the Classic really doesn't have any fuses. It's all thermal breakers.
Is this part of their infinite conquest to make things less predictable, harder to diagnose and ultimately less reliable? Wow, that sounds like it could really make for some interesting diagnosing "intermittent" electrical issues. Are they auto-resetting or manual resetting?
Is this part of their infinite conquest to make things less predictable, harder to diagnose and ultimately less reliable? Wow, that sounds like it could really make for some interesting diagnosing "intermittent" electrical issues. Are they auto-resetting or manual resetting?
Hi
Umm.... errr .... yes.
The ones that are buried where you can't get it without disassembly of the trailer are SAE Type II self reseting ( self welding ) units. They have no indication of what is going on at all. It actually took a while before I even realized they were buried down under the couch.
The more accessible ones are manual reset breakers with ( in some cases ) LED's on them.
The 120V power is set up with breakers ... except for a fuse that you disassemble half the kitchen to get to.
I did some parasitic and typical usage current numbers on my 2017 FC25FB.
With nothing "on", I get .12 AH on the inverter negative cable and 0.27 AH on the coach negative cable for a total of .39 AH of parasitic current draw. 0.39 AH x 24 hours = 9.36 AH per day times 30 days equals 280 AH. No wonder my original batteries were murdered while sitting in an unpowered storage lot for weeks at a time in its first year.
I also ran some typical usage scenarios for boondocking:
(Inverter line + Coach line)
Refrigerator on propane .12 AH + 1.0 AH = 1.12 AH
One fantasitic fan 0.12 AH + 1.7 AH = 1.82 AH
Two fantastic fans 0.12 + 3.0 AH = 3.12 AH
Refrigerator on propane + two fantastic fans 0.12 AH + 3.6 AH = 3.72 AH
Living room lights 1/2 bright add 1.1 AH
Living room light full bright add 2.0 AH
Inverter only 2.6 AH + 0.3 AH = 2.9 AH (no 120v load on inverter)
Inverter, TV, Cellphone and ScreenBeam Mini2 = 4.2AH plus 4.1AH = 8.3 AH
Furnace add 7.5 AH
My baseload while boondocking is typically refrigerator on propane with two fantastic fans running at 3.72 AH x 24 hours = 89 AH per day.
Once day per week I watch four hours of television at 8.3A which adds 33 AH to my baseload for a total of 122 AH per day.
And when it gets cold at night I find the furnace may run four times each night for 30 minutes consuming a total of 15 AH.
So my worst case scenario is 137 AH per day with baseload, four hours of TV and 2 hours of furnace.
Like UncleBob said, these results were measured on my Airstream and your results may vary.
__________________
2021 Northern-Lite 10-2 & F350 DRW PSD, 600W Solar/Victron/600A BattleBorn
146 nights 31,000 miles (first 10 months!)
Sold: 2018 GT27Q, 74 nights 12,777 miles
Sold: 2017 FC25FB, 316 nights 40,150 miles
Sold: 2013 Casita SD17 89 nights 16,200 miles
I did some parasitic and typical usage current numbers on my 2017 FC25FB.
With nothing "on", I get .12 AH on the inverter negative cable and 0.27 AH on the coach negative cable for a total of .39 AH of parasitic current draw. 0.39 AH x 24 hours = 9.36 AH per day times 30 days equals 280 AH. No wonder my original batteries were murdered while sitting in an unpowered storage lot for weeks at a time in its first year.
I also ran some typical usage scenarios for boondocking:
(Inverter line + Coach line)
Refrigerator on propane .12 AH + 1.0 AH = 1.12 AH
One fantasitic fan 0.12 AH + 1.7 AH = 1.82 AH
Two fantastic fans 0.12 + 3.0 AH = 3.12 AH
Refrigerator on propane + two fantastic fans 0.12 AH + 3.6 AH = 3.72 AH
Living room lights 1/2 bright add 1.1 AH
Living room light full bright add 2.0 AH
Inverter only 2.6 AH + 0.3 AH = 2.9 AH (no 120v load on inverter)
Inverter, TV, Cellphone and ScreenBeam Mini2 = 4.2AH plus 4.1AH = 8.3 AH
Furnace add 7.5 AH
My baseload while boondocking is typically refrigerator on propane with two fantastic fans running at 3.72 AH x 24 hours = 89 AH per day.
Once day per week I watch four hours of television at 8.3A which adds 33 AH to my baseload for a total of 122 AH per day.
And when it gets cold at night I find the furnace may run four times each night for 30 minutes consuming a total of 15 AH.
So my worst case scenario is 137 AH per day with baseload, four hours of TV and 2 hours of furnace.
Like UncleBob said, these results were measured on my Airstream and your results may vary.
It is semantics, but what you are quoting in your consumption figures as AH (Amp-Hours) is actually A (amps). A device draws n amps. It runs for h hours. That results in n x h Amp-Hours.
Are you watching television with a 120V AC television operating from an inverter? Your power consumption is quite high. My LR television is 120V, but my bedroom television operates from 12V and draws 3 amps.
Al
__________________
“You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO WBCCI 1322
2002 Classic 30 Slideout -S/OS #004
2013 Dodge 2500 Laramie 4x4 Megacab Cummins
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