Measured FWC power use

[Marco Cecala]

Marco, how big are your panels watts and size? Do you have any pictures.

Bill

Bill, I will get pictures for you in a couple days. They are 2- 100 watt panels. Here is the website; http://www.globalsolar.com

 

[Casa Escarlata Robles Too]

Photohc, I tried the series wiring but my controller isn't a 24v one. So I will keep them wired in parallel.
I did some more measurements with just one panel connected first the 45w got my reading a good output of about 90%.
Than disconnecting the 45w panel and connecting the 60w panel the most i can get is only 7 to 8 watts and that's with it directly pointed toward the sun.

Thanks for any help. I am in contact with the maker of the panel also to get some help.

Frank

 

[photohc]

Photohc, I tried the series wiring but my controller isn't a 24v one. So I will keep them wired in parallel.
I did some more measurements with just one panel connected first the 45w got my reading a good output of about 90%.
Than disconnecting the 45w panel and connecting the 60w panel the most i can get is only 7 to 8 watts and that's with it directly pointed toward the sun.

Thanks for any help. I am in contact with the maker of the panel also to get some help.

Frank

Frank, it sounds like a bad panel for the 60w.

 

[photohc]

I'm sitting in our 2013 Hawk on the Mogollon Rim outside of Payson, AZ while typing this. I will do a complete post regarding our Hawk and the power issues I have had but here are some initial thoughts;

We just had 4 gauge wire with an Anderson connector added to make vehicle charging better. With 2 days of rain it has really helped. I replaced the Exide group 27 batteries with Sun Extenders. People more knowledgeable than I can detail the reasons but these are meant to store more amperage for steady release. The Exide's and others are meant to push a lot of amps to start something.

I have 2 Global Solar flexible panels and like them. I also upgraded the IOTA charger to the IQ4. Changed the Global Solar charge controller to a Morningstar and it knows how to charge AGM cells.

We have an 85 liter 2 way Dometic. Adventure Trailers, (New Arizona FWC Dealer) is the best group of make it bullet proof and good looking did the battery to camper wire add and put 2 exterior grills and an additional fan to keep the fridge cool.

I cannot single out one fix that made things work well. We had hot fridge, poor charging issues, I just hit all problems at once. Stays charged well now.

I appreciate the usage and charge numbers shared. I'm getting similar results. No matter what you have, nothing beats being plugged in. I always connect to shore power 24 hours before leaving, fire up the fridge and load it with water bottles to get some mass cooling. We also have one of those little blue fans that circulates air. Reduces cold and hot spots and the thermostat can be set to a lower number.

Marco, thanks for your changes and observations. This is such a helpful forum and many ideas, for me, have come from here. I've done many of the same changes you have done and everything now seems to work much better. I'm curious on how big those Global Solar panels are?

 

[Casa Escarlata Robles Too]

Frank, it sounds like a bad panel for the 60w.

Thanks for your help.
I have contacted the maker and waiting for their reply.
Yes I feel that the panel is defective.
This shouldn't be such a complicated issue.
Just add a second "like" panel to the system and as long as I am under the controller's limit everything should work. "So he says".
Frank

 

[Marco Cecala]

I'll get some images of the panels as soon as it stops raining in Phoenix!! They measure 81.5” x 21.5” / 2,07m x 0,55m and weigh less than 2 pounds per square foot.

 

[Ethergore]

Ethergore - This might answer some of your questions:
I did notice a few things during my second trip studying truck charging of the camper battery.
On my trip back home, the camper battery bank was at around 94% to start the journey. I had used the solar to get my battery closer to full.
The truck charging setup actually did a nice job topping it off.
On my trip home, 2.5 hours later, my voltage was up to 14.2 volts and the amps were less than 1. The trimetric showed 100% of charge.
With the truck running still, I measured the truck battery and the truck's aux battery. They both tested 14.4 volts. Inside the camper we stayed at 14.2 volts. Only a 0.2 volt drop was significantly better than I would have guessed on my first trip (however this is at really low amps so you'd expect voltage drop not to be too much).
Once enough battery % had been recovered, the setup if given enough time can provide enough voltage to get to 100%.
I'm sure adding a higher gauge wire or dual alternators would really speed this up by letting more power being sent to the camper, but it's much better than I first thought.
There have been some good links here about battery charging. I'm certainly no expert but my understanding is that as batteries are heavily discharged they accept more amps at a lower voltage. As the approach full charge they need higher voltage as the amps decrease to complete the charge cycle. The truck charging setup does a decent job of doing just that.
Anyway, here's my summary of charging the camper by amps:
IOTA with 4 stage - up to 27-30 amps/hour
Truck with FWC setup - up to 14-17 amps/hour
Solar (depending on setup, sunlight, etc) - 4-6 amps/hour per 100 watts of solar
Hope that answers some questions so many of us have had with charging.

Thanks for the great info. Just to confirm you got the charge to 100% with just the alternator? The solar was disconnected?

Another interesting thing for me is how many volts you get from your alternator. No matter what I do I get 13.5 volts at my starting battery and less depending on the state of charge to my aux battery. I'm really jealous of this.

If your getting that much voltage to your aux battery there is no need to increase the size. I guess I got the small straw with alternators on my Tundra.

 

[DrJ]

Ethergore,
The truck had been charged up to about 94% before the journey by the solar. It was disconnected for the drive and still made 100% with just truck charging.
Reaching 14.2 volts was nice because it meant that we could float charge the last little bit.
There isn't a lot of power being transferred when the volts were at 14.2, because the amps were less than one.
It could be that the toyota alternator doesn't charge past 13.5 so it would never increase voltage enough to fully charge a camper battery. I'm just not sure in those models.
I've actually made a few phone calls to see what it would cost to add a dual alternator to my truck for more charging. It sounds pretty expensive.

I'm curious to know if anyone has had success with just increases the size of wire to the camper.

 

[Ethergore]

Ethergore,
The truck had been charged up to about 94% before the journey by the solar. It was disconnected for the drive and still made 100% with just truck charging.
Reaching 14.2 volts was nice because it meant that we could float charge the last little bit.
There isn't a lot of power being transferred when the volts were at 14.2, because the amps were less than one.
It could be that the toyota alternator doesn't charge past 13.5 so it would never increase voltage enough to fully charge a camper battery. I'm just not sure in those models.
I've actually made a few phone calls to see what it would cost to add a dual alternator to my truck for more charging. It sounds pretty expensive.
I'm curious to know if anyone has had success with just increases the size of wire to the camper.

Thanks again.

 

[RC Pilot Jim]

Global Solar website link

http://www.globalsolar.com/products/flexible-modules/rv

Calling them this morning

9/11/14 Update
Called them 3 times.....Never returned my call.

 

[RC Pilot Jim]

Turned on the Refer yesterday afternoon and recorded the following in last 24 hours:

Refer = 1.5 amps per hour net ****

Fant Fan = Low 1 amp, Medium 2 amps, High 3 amps

5 ea LED's in incandescent fixtures .(point) one amp per bulb - 5 bulbs = .(point) 5 amps. (half one amp)

12 volt outlets
charging a plane battery today, avg hourly current draw - point.75 amps net

Battery Doc 1.25 amp(spec rating) charger/maintainer (shell-shore power). Actually produces 1.1 charging amps Plugged this in last evening after the percent of full dropped to 95%. At 7 am "Bat Doc" had increased the percentage full to 98. Unplugged shell-shore power.

Drove truck to flying field this morning
Alternator voltage 13.6. Amperage 5.1 at idle 1,000 rpm.
Truck has been on and off all day - Refer still running.
Time now 5pm..refer still running...engine off 5 hours ...Percent of charge 95.

*** Lastly, this is the formula I used to determine avg amp draw per hour on the refer

Today Temp 87* Refer has been pre-cooled to 39*.

Temp maintaing begins. Refer cycles on - draws 3.0 amps. Within 30 seconds - draw drops to 2.5 amps for 2.5 to 3 minutes than turns off for 5-10 minutes. Then on/off cycle repeats. At 87* refer runs 6 min every 15 minutes. 6 x 4 = 24 minutes on (36 minutes off) - in a 60 minute period
60 min divided by 24 minutes running per hour Dividing 2.5 amps by 2.5 = 1.1 lets say 1.5 net amps per hour

I'm surprised the 110 liter Waecos are running 4.5 amps every hour as mine (Engle) cycles on and off. I would assume the Waecos do the same. Maybe they only draw 3 amps per hour net.

 

[Casa Escarlata Robles Too]

Thanks that's a lot on info to digest.
Frank

 

[RC Pilot Jim]

Yes that formula even has me scratching my head. That is how Engle got their avg running amps of "point 7" by testing to see the number of minutes per hour refer ran. If less than 30 minutes user divides amp reading by two to get a net average. .

The Waeco is probably less than 4.5 amps per hour because it cycles on and off.

 

[PaulT]

That which is of interest to the user rather than to the marketing person is the total amp-hours in a day. The artificially averaged current draw makes selling the refer easier as it looks like the power consumed is lower than it might really be. Typically, you have no real idea what the ambient temperature was or what the refer load was during the test.

Ambient temp usually starts at some low value early in the morning, rises during the day peaking in late afternoon and then falls to the morning low. Phoenix, Death Valley both would present a high ambient temp that makes the refer run more due to heat coming through the outside surfaces of the refer into the interior. Death Valley temps are harder for the refer to keep out than northern mountain high temps that may be much lower, especially if in some trees.

The refer load of which we usually have no information consists of how much and what types of food is being cooled, but more importantly, how many times and for how long the kid, (or Dad) stands there with the door open trying to see what might appeal to his hunger or thirst at the time or how many ice cubes get pulled from the freezer and replaced with liquid water at ambient temperature.Without this information, no average current value has any meaning.

If you know the current draw when the refer is running steady, and you know how many minutes the refer runs during the entire day, you can guesstimate the amp-hours the refer costs you to do its job. This value will change with seasons usage, etc.

Cut down on the door open losses by freezing some of the ice packs, when you have power available and in the morning, take your refreshments, lunches, etc out of the refer and place in a small cooler with a frozen ice pack or two. Refreeze the packs while underway, during the solar maximum of the day, or when on shore power. Your battery charge will thank you.

Manage the energy use that you can't overwhelm by covering the roof with panels. Orient your vehicle such that the refer side does not have direct sunlight on it during the heat of the day. Or just buy that Honda generator you really want anyway.

Paul

 

[RC Pilot Jim]

Good observation and advice Paul

 

[DrJ]

I'm surprised the 110 liter Waecos are running 4.5 amps every hour as mine (Engle) cycles on and off. I would assume the Waecos do the same. Maybe they only draw 3 amps per hour net.

The Waco 110 seems to run at 4.5 amps or not at all. I have not seen it run at a smaller amperage - although I could be wrong. When I read the information online it stated that it would run something like 70% of the time when the temperature is 85 degrees or higher. I think that would be pretty accurate.

I have noticed a great improvement with the usual things. Turning the fridge down, parking in the shade, running fans, etc...
I've actually installed 3 different fans to pull air away from the compressor fridge. This does seem to help a lot. I've noticed that I've used anywhere from 10-25 amps less a day by running the fans. They are all wired to a switch inside the camper. I'm still doing some testing on this, but so far it has seemed to help quite a bit. All 3 fans together take only 0.5-.0.6 amps per hour to use.

 

[DesertDave]

DrJ,

The online info I found (for the Waeco/Dometic 110L is this:
Current Consumption (12 volts DC): 2.2 Ah/h at +25°C ambient temperature,
2.5 Ah/h at +32°C ambient temperature,
both at +5°C interior temperature and -18°C in the freezer compartment

I think this is what you are referring to. Before I ordered my camper I asked FWC if they had any better info, and was told they did not. I used this info when I estimated my daily power usage for determining the size of battery bank I wanted (for my planned pattern).

Your fan installation is interesting to me. I was reluctant to remove the upper vent screen but your photo may give me the guts to try it. I already have the factory wiring in place to run the fan they offer on the absorbtion fridge, and there is a blank in the switch panel for a switch also.

Did your reduced amp consumption account for the additional draw of the fans? I am assuming they are only running when the compressor is running, correct? Thanks in advance for the info.

 

[billharr]

DesertDave, I have my fan wired to run with the compressor. I did put in a switch to turn it off, I just leave it on all the time. I might move the switch next to the fuse box just to get it out of the way. See my build for more information.


Bill


EDIT: DrJ how much noise does 3 fans make? I can hear mine outside but not inside the camper unless I am next to the fridge. I only have a top vent, do you have one or two vents?

 

[DrJ]

DrJ,

The online info I found (for the Waeco/Dometic 110L is this:
Current Consumption (12 volts DC): 2.2 Ah/h at +25°C ambient temperature,
2.5 Ah/h at +32°C ambient temperature,
both at +5°C interior temperature and -18°C in the freezer compartment

I think this is what you are referring to. Before I ordered my camper I asked FWC if they had any better info, and was told they did not. I used this info when I estimated my daily power usage for determining the size of battery bank I wanted (for my planned pattern).

Your fan installation is interesting to me. I was reluctant to remove the upper vent screen but your photo may give me the guts to try it. I already have the factory wiring in place to run the fan they offer on the absorbtion fridge, and there is a blank in the switch panel for a switch also.

Did your reduced amp consumption account for the additional draw of the fans? I am assuming they are only running when the compressor is running, correct? Thanks in advance for the info.

I did a trial about a week ago on this. Only 2 days of data so take it for what it's worth.
Truck parked in the sun all day - no shade - and vent on sunny side too. No one in camper all day - it was locked. So the fridge never opened. Nearly same day time temperatures 85-90 degrees. Fridge on 5.5-6 and stayed at around 35 degrees or colder.
No food it in.
1st 24 hours - I used 75 amp hours.
2nd 24 hrs - 3 fans running nonstop with fridge - 52 amp hours.

It's a pretty big difference but just from one day.

I'll keep watching, but for now I think I'll keep the fans turned on. At least during the day time hours.

The fan install is fairly easy. I looked at putting fans 2 and 3 next to the vent, but it was really easy to just attach them to the screen on the fridge.
If you already have the wiring and a switch - it's not too bad to add at all.

 

[DrJ]

DesertDave, I have my fan wired to run with the compressor. I did put in a switch to turn it off, I just leave it on all the time. I might move the switch next to the fuse box just to get it out of the way. See my build for more information.


Bill


EDIT: DrJ how much noise does 3 fans make? I can hear mine outside but not inside the camper unless I am next to the fridge. I only have a top vent, do you have one or two vents?

Bill,

Your build out is fantastic and the fan is a good idea. I had a similar setup because I took out a 3 way fridge. I have the upper and lower vent. The lower vent I just put a piece of foam over to insulate. The top vent is still open like yours.
I can hear the fans running from outside. Inside is barely audible. They are all computer fans and quiet.
I have slept just fine with them on before, but usually turn them off at night. I don't think the fridge runs as much then.

PS
I think we just hit 100 posts on this thread. I'm glad some of the information has been helpful and appreciate the ongoing discussion.