Road trip with solar panel between roof rack...

17037 Views 15 Replies 9 Participants Last post by MorganBrogan, Oct 31, 2014

eluo

Discussion Starter · Mar 7, 2013

Hello Forum! I'm planning a 8000+ miles cost to cost and back road trip this August. It is going to be Me, Wife and 2 preteen kids. I'm going to camp most of the nights and though about how I can make this trip as comfortable and convenient as I can for them. I had several ideas that came across my mind. One of them include mounting a 250 watt solar panel between the roof rack of my 04. I searched around the internet and didn't find any Sienna owner posting about mods with solar panel so I'm starting one here.

Why solar panel??? I was thinking that I can run a chest freezer and bring frozen food to the camp sites. I'm not sure if I will proceed. If I do, I will only need to get a few parts and the rest, I already have.

Parts:

250 watt solar panel - ~$400 Amazon
Solar MPPT Charge controller - ~$100 Amazon
12v Batteries - I have 4, 12v, 75ah but 2 is probably sufficient for my needs
Inverter - I have a Xantrex 1000W sine inverter
Cables - I have 50' roll of 4 gauge cable.
Chest Freezer - I have a 5 cf Kenmore. It may take up too much space. Considering the following smaller ones
- Danby 3.6 cf - ~$200
- Avanti 2.1 cf - ~$200
- Whynter 65 Quart - ~$500
- ARB 63 Quart (splurge ~$900)
Small Microwave - ~$100
Fan-Tastic Vent - Not sure of the cost and not sure if I want to punch a hole on the roof of my Sienna.

So my question to you Forum is, will this work? One issues that I can think of is charging the battery in the heat when parked under the sun. That is why I consider the vent fan. But I'm not sure if I can install that vent fan on the roof of the Sienna.

My other option is to wire the inverted to car's battery and run the chest freezer when driving. My concern is that there will be periods of time where I won't drive much for 2 to 3 days. Will stuff stay frozen in a unpowered chest freezer for 3 days in a sun heated car?

My other, other option is to run off 2 (or 4) of the 75 ah batteries that I have and charge those battery when driving. But is it safe to run a chest freezer off batteries in the heat of a closed car (probably up to ~115°f)?

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1 - 16 of 16 Posts

happycamper

· #2 · Mar 7, 2013

Not sure if you are open to alternate suggestions, but here is my idea:

Rent a smaller pop-up tent trailer.
This will have an indoor/oudoor grill and cook stove. It will also have a small 3-way fridge/freezer. It uses DC power (from the van) in transit, AC at campsites with hookups and propane at sites without hookups. You could probably rent one for less than the cost of purchasing all the items in your list. A smaller one means that you won't have to mess with trailer brake controllers and 7-wire trailer harness. You would have to run a wire for the fridge though.

eluo

Discussion Starter · #3 · Mar 8, 2013

happycamper, thanks for your suggestion but I have never tow and wouldn't want to start for an 8000+ mile trip that includes some unpaved roads. I can't disagree that comfort and convince is better but, cost is probably not less. I defiantly would consider it for shorter trip.

Quick cost breakdown.

Hitch ~$200
4 week rental for a popup tent trailer $xxxx
MPG penalty 5 mpg to 10 mpg of my usual 25 mpg is $320 - $850 in gas at $4/gal for 8000 miles

tcp

· #4 · Mar 8, 2013

i doubt a solar panel is going to come close to keeping any kind of chest fridge/freezer functioning. The 250 watt solar is in full sunshine maxed out. even the smallest compressor cooled chest is going to use a lot more than that and you have to consider clouds and night in the equation. the $$$ you are considering investing will buy a lot of bags of Ice along the route. Even a DC powered fridge will empty a regular size 24 RV battery down to nothing in a few hours. Some more reading on current requirements:

http://www.backwoodshome.com/articles2/yago102.html

eluo

Discussion Starter · #5 · Mar 8, 2013

tcp said:
i doubt a solar panel is going to come close to keeping any kind of chest fridge/freezer functioning. The 250 watt solar is in full sunshine maxed out. even the smallest compressor cooled chest is going to use a lot more than that and you have to consider clouds and night in the equation. the $$$ you are considering investing will buy a lot of bags of Ice along the route. Even a DC powered fridge will empty a regular size 24 RV battery down to nothing in a few hours. Some more reading on current requirements:

http://www.backwoodshome.com/articles2/yago102.html

Thanks for the link. The article is very interesting and informative. But nowhere does it indicate a compressor cooled fridge / freezer will drain a battery in a day. It does mention the solid state cooler draining the battery without running the engine. I am not looking to use the solid state coolers.

The article does strengthen my belief that the power from the solar is sufficient to power a chest freezer. The author used the following setup as his example.

100w panel (that cost $950 back then :0)
A highly efficient SunDanzer freezer rated at (~1000 current day price)
- 36.7 amp-hour/day load at 90° F (summer)
- 22.6 amp-hour/day load at 70° F (winter)

I am thinking of using a the following setup

250w panel ($400 shipped)
Not so efficient but a lot lest costly (under $200) chest freezer rated at
- 215Kwh / year (equivalent to 49 amp-hour/day)
- Adding an excessive 60% summer efficiency reduction will equate to 78 amp-hour/day

What I am concern about is the heat from the sun and freezer exhaust, trapped into an enclosed car. Heat is not good for electronics and battery. I guess this whole setup depends on if I want to take on the challenge of installing the roof vent. I have time to think about this...

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datsa noydb

· #6 · Mar 9, 2013

I thought you said you were going CAMPING? ???

Taking a chest freezer and a microwave were not even thoughts, let alone plans when we went camping with our kids. Yes, we did a LOT of camping, but we use a couple different pop-up campers. Our tow vehicles ranged from a Toyota pickup to a Camry to a Previa. We stopped camping before getting the Sienna, but still tow trailers occasionally, the Sienna is a MUCH more capable tow vehicle than any of our previous vehicles. In fact, my wife just returned from Arizona with a 5x8 U-Haul trailer in tow. She kept her speeds down to the 70-75 mph range and averaged about 15 mpg on the return trip.

I would seriously reconsider what constitutes "comfort" while camping and possibly reconsider about towing a trailer. The extra room inside the van will be worth it, if nothing else.

.

Reactions: 1

assc

· #7 · Mar 11, 2013

What kind of ridiculous unit is "amp-hour/day"? Use watts and make things much easier to understand.

I assume that usage is at 12 volts? If so, then 36.7 amp-hour/day * 12 V = 18.35 watts, which obviously is not a problem for a 250w solar panel, even if you can only run it part of the day (I think derating to 1/3 is reasonable).

And your second number of 78 amp-hour/day works out to 39 watts, which is also reasonable.

What is not reasonable is thinking that a chest freezer will work - at all - in the oven that is an enclosed car in summer. A car in summer can easily hit 140 degrees, and 180 is not unheard of. I doubt the freezer will work at temperatures like that.

To run your 78 amp-hour/day freezer, you'll need a battery with an RC of 125 http://www.wolframalpha.com/input/?i=78+amp-hour%2Fday+%2F+(25+A+*+1+minute)+*+16+Hour

I would double the RC to avoid draining the battery all the way, and make sure to use a deep cycle one. Also, avoid making yourself crazy, and use only a single battery and keep in mind that you won't be able to use the solar panel every day, so maybe triple it.

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eluo

Discussion Starter · #8 · Mar 12, 2013

Thanks to all that responded. I'm going to abandon the solar idea and just get one of the ARB 12V freezer. It is super-efficient. I will be able to run it off the Sienna's battery and set it to cut off at certain voltage to protect the battery. Here is a line taken form Amazon's product description

The 50-quart model is able to maintain sub-freezing temperatures in 90 degree heat while only drawing 0.87 amps per hour from a 12-volt power source

With this, everything is a lot simpler. No need for all the complicated setup that I mentioned before.

datsa noydb - This is more of a see the country trip and sleep at camp site to save money. I'm not planning to spend much time at the camp site other than shower and sleep.

assc

· #9 · Mar 12, 2013

eluo said:
0.87 amps per hour

BTW, It's not amps per hour (that doesn't mean anything useful). The power draw is simply 0.87 Amps. No per hour. An Amp is a continuous unit of measure. Watts is the same way. It's not Watts per hour, it's just Watts. 0.87 A at 12 V is 10.44 Watts.

If you multiply Watts and time, you get units like KwH - this is TOTAL energy, and does not specify draw, but how much energy exists in total - you can use that energy fast or slow KhW does not say.

oly

· #10 · Mar 13, 2013

OP, 8000 miles, wow that's more in line of an expedition! if you get a chance, please let us know how it goes before and after you head out on your adventure. I'm sure there are many of us here who would like to do some expedition travels with their family in their van. I'd like to know how your Sienna camping experience turns out. Dont forget the obvious necessities like a first aid kit, tire repair kit, lots of water, duct tape and spare oil/water hoses in case of any engine/transmission cracks/leaks.

Now if you've got unlimited funds, head over to the GTRV folks and just turn your Sienna into a GTRV Westy to fulfill all your family needs. ;D

brian_bp

· #11 · Mar 26, 2013

assc said:
What kind of ridiculous unit is "amp-hour/day"?

It is the unit which is almost universally used in the RV world, because deep-cycle battery capacity is given in amp-hours (not minutes of reserve capacity) and the energy budget with solar systems is worked out over a one-day average.

I agree that if you are tracking power sources and consumption and energy storage it makes sense to use the base units for power and energy, which are watts and joules (or watt-hours instead for convenience); however, it is easy to fall into the trap of assuming that the energy put into the battery equals the energy later taken out - it doesn't. If you charge a battery with (for example) 10 amps for an hour and it takes 14 volts to drive that current, that's 140 watt-hours; when you use that energy you're only going to get the same 10 amp-hours out at something like 12.4 volts (if the battery is roughly fully charged), which is 124 watt-hours. The lost power went to resistance in the battery.

brian_bp

· #12 · Mar 26, 2013

eluo said:
Here is a line taken form Amazon's product description
The 50-quart model is able to maintain sub-freezing temperatures in 90 degree heat while only drawing 0.87 amps per hour from a 12-volt power source

The description looks like it is from Amazon: ARB 10800472 Fridge Freezer- 50 Quart. ARB's page for this unit is ARB Fridge Freezer 50 QT (10800472)

As assc explained, the ARB description is sloppy; that should be 0.87 A average over the day. That spec seems very optimistic to me, since the current use while running is 7 amps, and so they are assuming that it needs to run only three hours a day in 90 degree F conditions.

breeves002

· #13 · Mar 26, 2013

I think this was a really cool idea. Quite a lot to take on if you ask me, but if done right ($$$) that would be pretty cool for future road trips. Not just for running a freezer! Having the vent would be a must. It would also help keep the car much, much cooler.

Enjoy your trip! Hopefully that freezer works out for you!

eluo

Discussion Starter · #14 · May 2, 2013

Quick update... bought lots of goodies for my van.

- ARB Fridge Freezer 50 Qt (10800472)
$677.48 shipped from Autoplicity

- CURT Receiver Hitches - Class 3
- WeatherTech Side Window Deflector - All 4 Windows
$225.61 shipped. Both from AutoAnything

- Airlift 1000
$63.63 after using a $40 off $100 form Advanceautoparts

- ScanGauge II Digital Trip Monitor
$115 after using coupon from Advanceautoparts

- Planning to get a hitch bike rack to carry 4 bikes

As for maintainance
- flushed the brake lines
- checked brake pads
- changed front rotors
- flusled trans oil and coolant about 10k miles ago
- Planning to change the oil (Mobile 1 extended performance 5w-20) and used oversize oil (Purolator PureONE PL20195) filter right before leaving for the 8k miles tirp
- Debating if I should change the timing belt... 04 with ~65k miles on it. What do you guys think?

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eluo

Discussion Starter · #15 · Sep 6, 2013

I'm back from my trip. Traveled a bit over 9200 miles from Coast to Coast and reach over 12,000 ft at Rocky Mountains. Overall, my Sienna did a great job. I managed to average 26 MPG as per ScanGuage, traveling mostly at the speed limit. I did manage to scrape a hole in the front exhaust pipe when pulling off to the side of the road. Other than that, the ATF temp reached 240F on a ~100F outdoor temp climb up Yosamite National Park. I got worried and pulled over for it to cool a bit. It was quite common to see ATF temp reach up to 230 on a long hill climb even when the air temp was in the 80's.

As for my ARB frig, I was able to keep it running all through out the trip without any issues. Having a icy drink after seeing the hoover dam at 100F was nice

MorganBrogan

· #16 · Oct 31, 2014

Hello Forum! I'm planning a 8000+ miles cost to cost and back road trip this August. It is going to be Me, Wife and 2 preteen kids. I'm going to camp most of the nights and though about how I can make this trip as comfortable and convenient as I can for them. I had several ideas that came across my mind. One of them include mounting a 250 watt solar power system between the roof rack of my 04. I searched around the internet and didn't find any Sienna owner posting about mods with solar panel so I'm starting one here.

Why solar panel??? I was thinking that I can run a chest freezer and bring frozen food to the camp sites. I'm not sure if I will proceed. If I do, I will only need to get a few parts and the rest, I already have.

Parts:

250 watt solar panel - ~$400 Amazon

Solar MPPT Charge controller - ~$100 Amazon

12v Batteries - I have 4, 12v, 75ah but 2 is probably sufficient for my needs

Inverter - I have a Xantrex 1000W sine inverter

Cables - I have 50' roll of 4 gauge cable.

Chest Freezer - I have a 5 cf Kenmore. It may take up too much space. Considering the following smaller ones

Danby 3.6 cf - ~$200

Avanti 2.1 cf - ~$200

Whynter 65 Quart - ~$500

ARB 63 Quart (splurge ~$900)

Small Microwave - ~$100

Fan-Tastic Vent - Not sure of the cost and not sure if I want to punch a hole on the roof of my Sienna.

So my question to you Forum is, will this work? One issues that I can think of is charging the battery in the heat when parked under the sun. That is why I consider the vent fan. But I'm not sure if I can install that vent fan on the roof of the Sienna.

My other option is to wire the inverted to car's battery and run the chest freezer when driving. My concern is that there will be periods of time where I won't drive much for 2 to 3 days. Will stuff stay frozen in a unpowered chest freezer for 3 days in a sun heated car?

My other, other option is to run off 2 (or 4) of the 75 ah batteries that I have and charge those battery when driving. But is it safe to run a chest freezer off batteries in the heat of a closed car (probably up to ~115°f)?

It is pretty good way to keep your batteries charged..Even I am planning road trip so there is plenty to learn for me..

Got similar charging system for my car and I am really excited to get some positive results now..

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