Enough solar panel for telecommuting?

[tlcm]

Hi all,

I'm thinking about getting a late model Interstate and using it to take my small family to places while I telecommute for work.
My question is: Is there enough solar panel to power my laptop (my 4g device can run from laptop tho it may be drawing more power) and possibly the lcd tv as a 2nd monitor? what else MUST need to use the battery.. refrigerator?

We've only rented a RV a couple of times for vacation... but I really don't know a lot about staying long term in RVs...especially working from a RV.

Thanks!

[PSchw]

I worked out of my 2013 Interstate without any problem. Driving and the generator will keep the power up I only added a Wilson 4G signal booster which worked great with my ATT mifi unit.

[UKDUDE]

I have never really understood the need for MiFi when most smartphones can act as personal hotspots; and a MiFi is an additional charge.


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[switz]

Verizon charges more for a hotspot on my phone than the monthly fee for the MiFi. Plus the phone is free to be a phone.

[PSchw]

Usually you can not use the phone and have a laptop online in the same time. I also can use Skype on the phone and still be online with the laptop.
I think it only make sense if you work on the road and have more then 2 data system online.

[lewster]

Originally Posted by tlcm

Hi all,

I'm thinking about getting a late model Interstate and using it to take my small family to places while I telecommute for work.
My question is: Is there enough solar panel to power my laptop (my 4g device can run from laptop tho it may be drawing more power) and possibly the lcd tv as a 2nd monitor? what else MUST need to use the battery.. refrigerator?

We've only rented a RV a couple of times for vacation... but I really don't know a lot about staying long term in RVs...especially working from a RV.

Thanks!

200 watts of solar and a 200 amp/hour lithium battery will more than suit your DC electrical needs for extended use. Most of the AI-EXTs that I have done had 300 watts of solar, but the small, high efficiency panels GS-100 @ 20" X 40") that we used are no longer available.

2 of our new 100 watt units should fill the bill nicely though.

[UKDUDE]

Originally Posted by switz

Verizon charges more for a hotspot on my phone than the monthly fee for the MiFi. Plus the phone is free to be a phone.

Ah yes, I guess it depends on the Verizon plan; I have a share everything plan with my wife and that seems to include the hotspot.


Sent from my iPhone using Airstream Forums

[greghoro]

MiFi units have the capability to add an external antenna, many phones don't. Important when you are away from metropolitan areas.

The Aluminum body can act like a Faraday shield and block radio signals for any device located inside the trailer.


Greg

[Protagonist]

Originally Posted by greghoro

MiFi units have the capability to add an external antenna, many phones don't. Important when you are away from metropolitan areas.

Exactly. The main reason I still use a MiFi is the ability to use an external antenna with it.

[Al and Missy]

Going back to the original question, i.e. powering a laptop with the interstate solar panels, it appears to me that the question is not complete. I would think that the power consumed by a laptop is a relatively small fraction of the power required to live in the Interstate each 24 hours. With the need for lights, air conditioning, vent fans, or heat, cooking, water pump, etc., if there is enough power to do that, would adding a laptop have much effect? What am I missing?

Al

[Protagonist]

Originally Posted by Al and Missy

With the need for lights, air conditioning, vent fans, or heat, cooking, water pump, etc., if there is enough power to do that, would adding a laptop have much effect? What am I missing?

One thing you're missing is A/C. You can't run the air conditioner off the inverter, so you've got to have shore power or generator power to use it. Which means your solar panel makes no difference if you've got to run the A/C.

So assuming you're NOT running your A/C… A laptop would have exactly ZERO effect, in my opinion. Laptops have their own batteries and don't need to be plugged in to use them. If you carry a spare laptop battery just in case, all you have to do is recharge your laptop battery at the exact same time as you run your generator to charge your house batteries.

Your stock solar panel will not really recharge your house batteries, only stretch them a little farther than they'd go without the solar panel. You still need to run the generator every day or two to keep the batteries topped up. And worse in summer, because for the solar panel to do its job you've got to park in the sun, and that means your Interstate will heat up faster and hotter, so that you WILL need your A/C and your generator to run it. So plan on parking in the best afternoon shade you can find and not getting the benefit of the solar panel.

As an aside… It's even better if you have a 12vDC cigarette lighter plug for your laptop, too. If you DO operate your laptop while it's plugged in— as opposed to operating from the laptop's battery and only plugging in to recharge— it's kind of silly to take 12vDC power, invert it to 120vAC power, just to have your laptop's brick convert it right back to DC power. Much more efficient to go with a 12v power plug, so the brick only has to do the voltage change. Fewer amps wasted that way.

[idroba]

Originally Posted by Protagonist

As an aside… It's even better if you have a 12vDC cigarette lighter plug for your laptop, too. If you DO operate your laptop while it's plugged in— as opposed to operating from the laptop's battery and only plugging in to recharge— it's kind of silly to take 12vDC power, invert it to 120vAC power, just to have your laptop's brick convert it right back to DC power. Much more efficient to go with a 12v power plug, so the brick only has to do the voltage change. Fewer amps wasted that way.

Unless your laptop operates directly on 12 volts DC, and very few of them do, it matters not if you go from 12 volts DC to 120 AC and then through the computer power supply to whatever the computer needs (often 18 to 22 volts DC) or if your 12 volts DC is converted to AC to raise the voltage, then back to the 18 to 22 volts DC through a DC to DC converter unit. The same inefficiencies exist.

The worst inefficiency though, I will state, is a pure sine wave inverter which takes maybe 2 amps at 12 volts to simply sit there doing nothing. This is typical of the WFCO sine wave inverters Airstream has as original equipment and the same as the Magnum which others supply. All of those inverters are inefficient at low loads, and terrible if not shut off when not being actively used. They do not do cell phones well..... LOL. A cell phone load might be 3 to 5 watts to charge.

The inexpensive small modified sine wave inverters are usually much more efficient and will work your laptop power supply just fine. The only high efficiency sine wave inverter I have identified is a 300 watt Morningstar Pure Sine. It has a standby loss of about 0.4 amps, and in "search mode" far less than that.

[tlcm]

thank you all for the comments and answers... not sure if I'm more

re: mifi device, i'm planning to use my phone, which I know drains the battery fast, so may require more amps charging? also, I do have a mifi device as backup which is nice especially since it's a different carrier and also runs on WiMax vs 4G LTE.... not sure any phones have WiMax.

my thinking/plan for getting a sprinter is to kind of use it as a mobile office? drive to the beach, lake, park, etc... where wife, kid and dog can play all day while I work in the sprinter... and possibly dry camp there for a couple of nights?

I do not believe we need air conditioning... at least in California, we've never needed air conditioning in a single-story house or where there's shade or ocean breeze... so I think as long as the solar panel can power the frig (not a necessity), laptop (for 8 hours), 4G phone, lcd monitor (not a necessity either), some night lighting and someone said water pump. cooking can be done with propane on stove top if not enough electricity.

about the generator, does the Interstate use propane or gas? we hated the generator on the rental RV because it was sooooo loud! felt like we were bothering everyone around us. I'd prefer to be Net Zero with a motorhome (when not moving of course... or until there's a solar powered motorhome one day)

[73shark]

The generator uses propane and it is loud. You can add a muffler which quiets it down below the level of the A/C on High.

[dljosephson]

Lots of questions there. We have a Sprinter-based Roadtrek with about 150 watts of solar panels, and an Airstream 310 with 400 watts. You have to be very careful about budgeting power and monitoring battery condition but it is possible to work out of a Sprinter running on solar. You may need to add more panels than come with the stock installation. It also depends on how big a battery you have onboard.

There are phantom loads typically of 10-40 watts for relays, status lights, and the fridge, which runs on propane but requires a very little bit of electricity for its brain. Your laptop computer will use 30-80 watts, a phone or Mifi very little if you have an efficient charger. Say you have an office load of about 100 watts. 8 hours times 100 watts is 800 watt-hours of energy.

Protagonist's comments are spot on. You will need to manage some combination of solar, plug-in, generator and batteries and you'll learn to cope, you'll probably do OK if you have all available roof space covered in high efficiency solar panels. We haven't tried full 8 hour days but 150 watts of solar panels have been enough nearly every time. 400 (and a big battery) means we can stay in the shade for a day or so.

If you get into the arithmetic of figuring out how much energy you can store with the power and time you have available, realize that you lose about 50% charging and discharging the battery. In direct sun in California you can plan on 5 hours of full power charging (so, if 100 watts of panels, 500 watt-hours per day, of which you will actually be able to use about 250 if you store it in batteries.) Likewise your batteries hold about half their rated capacity -- a 220 amp-hour 12 volt battery actually holds about 1300 watt-hours, not the 2640 you get by multiplying 12 x 220. This is because you don't want to discharge your battery more than about 50% if you want it to live.

[Boxster1971]

Originally Posted by tlcm

Hi all,



I'm thinking about getting a late model Interstate and using it to take my small family to places while I telecommute for work.

My question is: Is there enough solar panel to power my laptop (my 4g device can run from laptop tho it may be drawing more power) and possibly the lcd tv as a 2nd monitor? what else MUST need to use the battery.. refrigerator?



We've only rented a RV a couple of times for vacation... but I really don't know a lot about staying long term in RVs...especially working from a RV.



Thanks!

Unless you plan to add more solar to the Interstate you are considering it may not be the vehicle for your intended use. The late model Interstates only came with 50 or 100 watt solar panels depending on the year since about 2010. I upgraded to 400 watts of solar on mine so we could dry camp without much problem. If I were buying today I'd get a Roadtrek E-Trek or a unit from Advanced RV that are total electric without that noises propane generator.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[dljosephson]

I was all set to be impressed by the E-Trek but its a cruel joke. It's really pretty and I really wanted to like it. You basically need to run the engine to cook breakfast. The optional fuel cell from Efoy is neat technology but the biggest one produces 90 watts and you have to buy the special methanol fuel from them at $193 for 31 kWh, or about 50x what power costs at home.

400 watts of solar and some large batteries go a long way toward making it practical, especially with newer solar panels that are getting more efficient. We carry an extra 100 watt one that we put out in the sun when we're parked in the shade, and that usually works for a long weekend if we are careful.

[lewster]

Originally Posted by dljosephson

Lots of questions there............


If you get into the arithmetic of figuring out how much energy you can store with the power and time you have available, realize that you lose about 50% charging and discharging the battery. In direct sun in California you can plan on 5 hours of full power charging (so, if 100 watts of panels, 500 watt-hours per day, of which you will actually be able to use about 250 if you store it in batteries.) Likewise your batteries hold about half their rated capacity -- a 220 amp-hour 12 volt battery actually holds about 1300 watt-hours, not the 2640 you get by multiplying 12 x 220. This is because you don't want to discharge your battery more than about 50% if you want it to live.

LiPo batteries are a very attractive energy storage alternative to lead acid based batteries.....even Lifelines!!!

[dljosephson]

LiPo and batteries are indeed very interesting and can be used to about 80% of capacity without chewing into their service life, but they are very intolerant of misuse, unlike lead-acid or even AGMs. If Elon Musk can get enough people on his bandwagon for smart, processor-managed battery systems it could be a major shift. I have a 20 AH Li-ion pack for radios and stuff, it's about 1/4 the size and weight, and 4x the price of an equivalent AGM.

[BoldAdventure]

Originally Posted by tlcm

Hi all,

I'm thinking about getting a late model Interstate and using it to take my small family to places while I telecommute for work.

How big is your small family and how comfortable can they be in an Interstate?