27 replies to this topic

[iowahiker]

roverjohn,  I went over the math in the truckcamperadventure link article and I can not find a math error.  The author does ramble in his discussion.  Just curious, what is the authors math error?  Thanks.

[roverjohn]

I didn't say he had any math errors.

Problems with the article I see after a quick read.

1. He ignores the fact that 12 volt swing motor fridges have been around since the 60's so making a brushless version of their previous AC compressors is not like a moon launch.

2. He ignores the fact that absorption fridges are actually more efficient than they are given credit for especially when using propane.

3. He recommends insulating the fridge compartment when any additional insulation should be directly applied to the fridge itself. It makes no sense at all to prevent the compressor coil from shedding heat. It would be one thing to try to lower solar gain between the fridge and an outside wall but to say installers are 'doing it wrong' if they don't insulate the fridge compartment is just wrong. Unless I'm reading it incorrectly which I may be.

 

That whole article seems to be a commercial for Danfoss which would be Ok if he had stated that.

Edited by roverjohn, 18 February 2019 - 08:50 PM.

[roverjohn]

Rando,

If the OP can't use the integral BMS as a charge controller he needs one of those too so I amend my first post.

Is it hidden in the Xantrex maybe?

[iowahiker]

roverjohn,  The purpose of the link was to show a third-party, real world example of the limitations of a 200 watt solar panel system with a reasonable amount of numeric data.  The link author also drives routinely as the OP plans to travel.  

 

The Danfoss motor is also variable speed per their web site (moon launch?  ) and so a very nice "state of the art" 12 volt compressor system used across a very wide range of refrig sizes.  Most folks combine the max amps of around 4.4 with a duty factor but the variable speed capability makes for a more interesting calculation of battery load.  The link author's addition of auxiliary components of the refrig and power demand was the first documentation of this in my research.

[LosAngeles]

Hi there. 

 

Hallmark is willing to make a 9.5' Everest by using the side walls of the Cuchara.

 

A Cuchara is a very different build - a lot more stuff in it. We dont want a Cuchara.

 

fair question tho. :-)

 

and.... thanks to you and everyone else I am realizing that I should have at least 300 W and ideally more on the roof. 

 

I have a portable, and will have a Zamp port added to the build... but the way we travel I dislike using the portable. Yes I am lazy, and we are often on the move.... but yes campsites can sometimes be shady.   ;-)

 

ideally maybe 2 x 190 watt hard panels on roof would rock.  :-)

 

thanks to all for all the great info. Now I need time to digest it. ;-)

 

J.

 

 

LA-
A couple of comments.

Isn’t the Everest a 8.5’ camper? The Cuchara is their 9.5’ camper last time I checked. (I have an Everest).

In my build with their standard fridge we went with 2, 100 amp flexible solar panels and 2, 220AH 6 volt batteries. Through my negligence in not monitoring my fridge (which had been mistakingly turned up to the max on a long trip) I overused the batteries and am now in the process of replacing them with one 100 AH Battleborn battery which is equivalent to what I had. Prior to that episode the set up provided a good balance and never left us without charged batteries.

Since you are installing a much larger fridge and will have the additional storage capacity of a second BB battery I would reccomend considering increasing your solar capacity at least another 100 amps if you have the space on the roof.

[LosAngeles]

Hi all again - 7 months later. :-)

 

So we are finally about to place our order for our 9.5 foot long Hallmark pop up truck camper. 

 

How is this for a (revised) power system? 

 

* * in terms of amount of solar panel WATTS specifically. * *  

 

I want to make sure i have enough solar panel power. The fridge will be the biggest draw, by far. (plus the Truma Combi running much of the night, in fall  / winter / spring / subzero…… midwest.

 

Plan below has 540 watts solar, but for an extra $400 or so I could have a 4th 180 watt panel added - so that would make it 720 watts solar total. Should I do the 4th 180 watt panel? Easier + cheaper now than later. (at the time of build)

 

Planned system:

 

200 amp-hours of  Battleborn Lithium batteries. (2 x 100 amp hour batteries)

 

Propane for stove…. and Truma Combi. (hot water and air.)
(of course 12v needed to run the Truma Combi too)

 

7.2 CU side by side. 2 way compressor. Novacool RFS7501 fridge.

 

Maxx fan.

 

Interior LED lights.

 

Solar System: 3 X 180 “Grape” solar panels on roof = 540 watts

 

(or maybe 4 panels? = 720 watts)

 

“(each panel) Produces on average 45 Amp-hours/540-Watt-hours per day, EACH” (so 135 amp-hours a day for 3, on average, when the sun is out i suppose)

 

Power Converter 60A Mini Lithium Ion Power Center Black PM4060LIK 

 

Victron 100/30  SmartSolar charge controller MPPT  Solar Charger w/ Bluetooth Lifepo4 Ready

 

Xantrex 817-2080 Freedom XC 2000, 2000 Watt Pure Sine Wave 12 Volt Inverter/Charger

 

Victron BMV 712 Battery Monitor w/ Bluetooth Lifepo4 Ready

 

2 (two) x Battleborn 100 amp hour (each) Lithium

 

Other occasional loads:
Small microwave. Blender. computer maybe.

 

4 season camping. Yes there will be some rain and short grey days…. sometimes below freezing. Sometimes higher altitudes. Sometimes in cloudy Pacific NorthWest.

 

 So the ability to discharge the Lithuim 90% with smaller bulk and weight has advantages.

 

We mostly boondock. We prefer the quiet.


Occasionally we stay someplace for 2 nights, but often drive around a bit, to explore, each day (so the F-350 would also help a bit charge up the batteries)

 

Thanks for any and all thoughts.

J.

Edited by LosAngeles, 28 September 2019 - 04:20 AM.

[rando]

I am not sure where you plan on using your camper and therefore how much sun you will get, but 540W of solar is already a LOT of solar.    For reference we get by with 160W and had 240W for a while and that was more than enough.   Admittedly we spend most of our time in the sunny rockies and south west.   Unless you have unusually high power demands, 360W would probably suffice and 540W would be sufficient overkill.   540W is already a little bit over the max panel watts for the 100/30, so you may need to go up to the 100/50.    720W is a little too much even for the 100/50. 

 

Why not switch to a Victron inverter or inverter charger instead of the Progressive Dynamics and Samlex, given that you will be using Victron for everything else?   The progressive dynamics power center looks like dodgy RV junk to me, and does not provide the right voltage for lithium anyway.

 

https://www.victrone...y.com/inverters

https://www.victrone...erters-chargers

[LosAngeles]

Good points... but keep in mind that we are in the midwest, with very short winter days, grey skies, cold weather so TrumaCombiPlus needs juice to run all night.... we will camp 4 seasons. 

 

also - a partially shady campsite (many trees here) will cripple solar gathering. 

 

My thought is... if I pay another $400 to get a 4th panel at build (to get 720 watts) then MAYBE we wont need to frequently bust out the generator... and for me that is worth $400... to worry less about power. 

 

 

the amount, duration and intensity of the sun is very different here (especially late fall, winter, spring) than where you are in  sunny rockies and south west.

 

 

I am not sure where you plan on using your camper and therefore how much sun you will get, but 540W of solar is already a LOT of solar.    For reference we get by with 160W and had 240W for a while and that was more than enough.   Admittedly we spend most of our time in the sunny rockies and south west.   Unless you have unusually high power demands, 360W would probably suffice and 540W would be sufficient overkill.   540W is already a little bit over the max panel watts for the 100/30, so you may need to go up to the 100/50.    720W is a little too much even for the 100/50. 

 

Why not switch to a Victron inverter or inverter charger instead of the Progressive Dynamics and Samlex, given that you will be using Victron for everything else?   The progressive dynamics power center looks like dodgy RV junk to me, and does not provide the right voltage for lithium anyway.

 

https://www.victrone...y.com/inverters

https://www.victrone...erters-chargers

[Stokeme]

I would respectfully suggest that you should give consideration to having a controller capable of handling that much W. You will need to be aware about shedding panels when you would experience full solar gathering. Frying something at capacity (720) would be a possibility.

[LosAngeles]

Yes indeed - I'll have to circle back with Hallmark - thanks. 

I would respectfully suggest that you should give consideration to having a controller capable of handling that much W. You will need to be aware about shedding panels when you would experience full solar gathering. Frying something at capacity (720) would be a possibility.