Solar for Car

[myway_1]

What type of solar set-up is best for a car-dweller?

Each day I will be using a small laptop about 8 hours, a tablet about 1 hour, a smartphone a few minutes and an LED light a few hours. I will buy an extra internal battery for the laptop. I would like an electric cooler but it's not a necessity.

I wouldn't want to attach a rigid solar panel to the roof. I'm not sure how I could vent a deep cycle battery.

I'm assuming a roll-up or suitcase solar panel would be the way to go.

Could I replace the car's starter battery with a deep cycle battery, connect the solar panels to it and power / charge my electronics (including the cooler) via the cigarette lighter?

Or is there a better way?

 

[blars]

If you replace the starter battery with a FLA battery, you want a Marine one. (Compromise between starter and deep cycle.) Try to see if you can get a bigger one in.

 

[TMG51]

What type of solar set-up is best for a car-dweller?

Each day I will be using a small laptop about 8 hours, a tablet about 1 hour, a smartphone a few minutes and an LED light a few hours. I will buy an extra internal battery for the laptop. I would like an electric cooler but it's not a necessity.

I wouldn't want to attach a rigid solar panel to the roof. I'm not sure how I could vent a deep cycle battery.

I'm assuming a roll-up or suitcase solar panel would be the way to go.

Could I replace the car's starter battery with a deep cycle battery, connect the solar panels to it and power / charge my electronics (including the cooler) via the cigarette lighter?

Or is there a better way?

Deep cycle batteries are for long, slow use. Starter batteries are for immediate, high use. You need a starter battery for your engine. There should be some way for you to add a "house" deep cycle battery and solar, but, some people do make do with only an engine battery. Marine batteries attempt to be both "starter" and "deep cycle" batteries all at once. You could potentially replace your engine battery with a marine battery. If you have only an engine battery, be sure to add a cut-off that prevents you from draining it and leaving yourself stranded.

The idea about no permanent panels on the roof / lugging around a suitcase thing is one I don't see as a best solution. I see how you might be concerned about modifying the vehicle, or making it look unstealthy. But I would suggest that carrying a suitcase thing in and out of the car is not only going to be a more attention-drawing behavior, but also cumbersome and less opportune for recharging. You may be able to obscure solar panels in some kind of roof rack so that they are not obvious at a glance.

Get 12v cords for your laptop and any other device to run them off the ciggy plugs. Depending on what cooler you end up with, you may or may not power that off the ciggy plugs as well, but check the draw first and don't treat a ciggy plug as a "set it and forget it" method of installation - they should only be used for things you're going to plug and unplug regularly. Anything permanent or with a significant draw should be wired in.

 

[mayble]

How about one of these small solar USB chargers?
http://www.amazon.com/dp/B00M16KLM8?psc=1
Would that work?  Has anyone here tried something similar?  I'm curious how well it would keep up with normal phone/tablet use.
As far as lighting, I'm considering a few LED puck lights with rechargeable AAA batteries, something like this:
http://www.amazon.com/Fulcrum-30010...00R7PM36/ref=sr_1_3?ie=UTF8&qid=1450802981&sr
and
http://www.amazon.com/gp/product/B0...-201d-4322-b781-e6e300a44a83&pf_rd_i=13535441

 

[lonewolf2koc]

Roll up panels are super expensive. Suitcase panel at 100 W is simply too little power. 100W may sound big but in reality it's not in actual real-world environment. My rule of thumb is a 100 W panel is really only 50 W. So double up on the panels.

I'm using four 120W flexible solar panels and only getting 10-12 A from 10:00-15:00 hrs in Southern CA. The permanently mounted panels (2 of them) only output about 2.5-3A max. Semi flexible solar panels are very sensitive to proper placement. 5-10 degrees off is a difference between 3 A vs 10 A. The problem with placing it on your windshield and front hood is that it attracts attention and you'll be a suspicious target vs stealth.

I did a simple test with a VMAX Tank 170 Ah battery. I consume about 60 W for about 8 hours/day (thermoelectric cooler). Turn off at night and resume back. It took about 3-4 days of full sun to refill the AGM battery. I had to use shore/grid power and charge the 170 Ah AGM w/ the Noco Genius G26000 for about 12 hrs to fully top it off and prolong the life. What I can say about solar is that you'll need at least 4. 8-12 panels are more realistic to get the AGM batt filled. Unfortunately 8 panels will not fit most mini van let a lone a small car.

With some preliminary real world load tests already done, I'll have to get at least two 170 Ah AGM batts. When the 1st is 40-50% depleted, I'll go to the 2nd one. I'll let the 1st one fully charge by solar (if possible). Come to think of it, I think at least three 170 Ah AGM batts will be needed because it take 3-4 days to fully charge a 170 Ah and you'll likely use up a single 170 Ah every day or day and a half.

You'll have to use your car alternator and/or 3rd party generator to fully charge these AGM batts. Not giving them the well-deserved full charge cycles will shorten its service life. Utilizing electricity off-grid is quite costly and not cheap as most people think.

What type of solar set-up is best for a car-dweller?

Each day I will be using a small laptop about 8 hours, a tablet about 1 hour, a smartphone a few minutes and an LED light a few hours. I will buy an extra internal battery for the laptop. I would like an electric cooler but it's not a necessity.

I wouldn't want to attach a rigid solar panel to the roof. I'm not sure how I could vent a deep cycle battery.

I'm assuming a roll-up or suitcase solar panel would be the way to go.

Could I replace the car's starter battery with a deep cycle battery, connect the solar panels to it and power / charge my electronics (including the cooler) via the cigarette lighter?

Or is there a better way?

 

[myway_1]

" I'm not sure how I could vent a deep cycle battery."

If it is true that AGM batteries don't need to be vented, then I would get one of those for a house battery.

 

[Suanne]

Last winter was my first time using a small 7w Goal Zero solar panel. I was really impressed with how quickly it recharged. With fully charged devices and batteries, I could go 3 sunny days without having to use my car to recharge.

I used my smart phone more than my laptop because it uses less electricity, and had two lithium polymer batteries (16.8 and 13 Ah). On average, I would say I used my smartphone about 9 hrs and laptop about 2 hrs each day. I turned them off between use. (If interested in more info, go to http://suanneonline.blogspot.com/2015/06/product-reviews-for-power-snowbirding.html.)

My goal this winter is to go 10 days on solar only. So, I just got two 14w Renogy panels. I was so impressed with the Goal Zero panel, I hope these perform as well.

Suanne

 

[Oberneldon]

Myway_1,

Suanne is on the right track for solar in a small vehicle. I have the 7 watt goal zero too but mostly use it for backpacking as I use ,pay iphone for tracking my routes and need to recharge on long hikes. The unit has the feature of charging from USB as well and the batteries are swappable so you could charge 4 batteries at a time and have some spares when one set is drained. It is not going to power even a small laptop for any time.

I just got rid of my power hungry laptop this year for a notepad to reduce power consumption. The point is correct to charge your devices with a 12 volt cord. Since you need 8 hours on a laptop this is your focal point so I don't see any way to do this without a small suitcase panel setup that will give you the watts you need. You need to figure the wattage you need and size appropriately.

As for AGM batteries not having vents, I do know my Prius AGM has a side vent that is vented through the floor with a tube. I use lead acid gel cells for my storage (no vent) but charge off them off my Prius as you know. Gel cells are relatively in expensive for the 12v/7 -9 ah size. I run 3 in parallel to run my compressor fridge at night. Suanne is using Li batteries and although expensive they are less eager to be pleased to a specific charge.

Brent

 

[myway_1]

Suann, I have read quite a few of your blog entries. Lots of helpful information there. Thanks for setting down your experience so others can benefit!

I would like to use a phone or tablet as my primary internet / video device but my eyesight just isn't good enough and my thumbs are too pudgy. I'm hoping that a very small laptop won't use too much electricity. How do you charge your laptop?

 

[myway_1]

Brent, I have read quite a few of your blog entries too. Again, lots of helpful information. And thank you too for making the effort so others can benefit from your experience.

What was your reasoning in going with the 3 gel cells as opposed to a second AGM battery? Can the gel cells be charged by solar panels?

The notebook you bought is what I had in mind for a laptop. When I say small, I don't mean a 13",  I mean even smaller.

 

[Oberneldon]

Myway_1,

I chose gel cells as I have design experience with them. I get 12v with 8 ah for about $15. I lived with 2 last year at 7ah each but I pushed the limit of the batteries once it got 90 deg outside keeping my compressor fridge running from 8 p to 6 a, so upgraded to 8 ah and 3 batteries.

I actually could have run a second AGM matched battery for my Prius but at $200 for the battery and no good space for the second battery the gel cells fit the space better. If your vehicle is not set up for charging an AGM battery and you want to charge off the alternator you need one of these to get the voltage up there to fulfill the AGM battery needs. At $165 more $$$

http://www.powerstream.com/DCC.htm

I decided on the 400 watt PSW inverter $150 (that I needed anyway) and multi Chemistry charger that I can condition my gel cells from the Prius 12 v battery and Prius AGM when on shore power.

I consider my gel cells a throw-away deal at the price point if I happen to kill one.

Yes gel cells are lead acid and can be charged from solar.

I didn't measure my RCA notepad but it charges off the 2.1 amp USB like my iPhone and iPad not a power brick like my old laptop.

I have not tried Li power packs for jump starting vehicles to run my devices like Suanne. I did look at Li batteries to replace the gel cells but although the actual Li cells inside take up less space that the gel equivalent, they kept the battery packaging size the same so I gained no space, that is important to me.

Let's say you are running the notepad at 2 amps per hour you will need 16 amp hours. My 3 gel cells at 24 ah will handle this, but how would you replace what you use. For me it's my Prius as a generator or solar. Suanne's two 14 watt solar panels giving less than 28 watts will make up for the notepad but you still have other needs. A suitcase with more wattage is what you need. Remember that solar on the label is not what you get unless you have a perfect setup.

So you need storage and you need to replace the storage you use every day. So add up your amps or wattage and figure what you need to store and charge knowing you can't deplete your batteries and you don't get perfect solar conditions.

This is why I worked around using the Prius as a generator for my charging so I didn't need to take up space for solar. Remember the Prius only runs to charge the batteries the way we use it, so it is highly efficient.

Brent

 

[myway_1]

Brent,

Will your RCA notebook charge from 0 to 100% overnight?

Can your gel cells be fully discharged or do they have a threshold beyond which you shouldn't go?

Joe

 

[akrvbob]

Is stealth an issue? If not I'd get one of these 120 watt bendable solar panels for $240 and velcro it to your roof.
http://amzn.to/1YzBn8W

I'd spend the money and get a decent AGM deep cycle and sit it on the floorboard on the passenger side. Then I'd pick up a Renogy or Tracer solar controller, a MC4 extension, in-line fuse and you're done. Really not difficult at all. Figure $300 for panel and controller and $200 for battery.
Bob

 

[Oberneldon]

My_way1,

I just got the RCA notebook so I have not gone to 0 and I have yet to use it charging off the Prius. Since it charges like my iPad via 2 amp USB. I would charge it during the day off the Prius system in ready mode and not charge off the house battery setup as I use that for my compressor fridge and USB fan.

Good question on the gel cells. No they do not like being abused. If you need that depth of discharge its Li I guess. I have a dedicated volt meter on my house battery setup and don't let mine go below 12 volts, although a bit under is probably possible I just don't do it and why I added the third battery this year.

Brent

 

[Suanne]

Suann, I have read quite a few of your blog entries. Lots of helpful information there. Thanks for setting down your experience so others can benefit!

I would like to use a phone or tablet as my primary internet / video device but my eyesight just isn't good enough and my thumbs are too pudgy. I'm hoping that a very small laptop won't use too much electricity. How do you charge your laptop?

Although I called it a laptop, it's really a tablet that I use like a laptop. It's an ASUS Transformer. I got it because it uses less energy than a regular laptop (Atom processor and solid state drive), has a full-size keyboard, and a 500GB traditional drive in the keyboard. But, it still uses much more power than my smart phone, an old Nexus 4. But, like you, I don't "type" very well on my phone and so would crack open my laptop/tablet if I had any serious keyboarding to do.

I just got a bluetooth full size keyboard to use with my phone to see if that will help me use my phone more to save power. It seems to work fine, but I need to use it while living out of my car in order to give it a serious review.

I charge my laptop using the lithium polymer batteries which have been recharged using either solar, my Prius' 12v plug, or a regular 110 plug (with a USB cable). If I'm in a library, fast food place or coffee shop with 110 available, I'll recharge my laptop/tablet there as well.

Hope that helps. Suanne

 

[myway_1]

Is stealth an issue? If not I'd get one of these 120 watt bendable solar panels for $240 and velcro it to your roof.
http://amzn.to/1YzBn8W

I'd spend the money and get a decent AGM deep cycle and sit it on the floorboard on the passenger side. Then I'd pick up a Renogy or Tracer solar controller, a MC4 extension, in-line fuse and you're done. Really not difficult at all. Figure $300 for panel and controller and $200 for battery.
Bob

Would there be any way to attach the velcro in such a way that it could be removed without damaging the paint (thinking down the road to when I might need to sell the car)

Are these types of panels rugged enough that they could be placed on the ground (what if a strong gust of wind blows it over)

 

[B and C]

Would there be any way to attach the velcro in such a way that it could be removed without damaging the paint (thinking down the road to when I might need to sell the car)

Are these types of panels rugged enough that they could be placed on the ground (what if a strong gust of wind blows it over)

Velcro will come off a vehicle with a hair dryer, Goo Gone and some elbow grease.  Bendable solar panels will conform to the roof and should have a very negligible affect on gas mileage.  With the Velcro and panel together it would be less than a 1/2 inch tall.  If your are worried about the wind blowing them over if set up as a remote panel, they have grommets in them that you could use a long spike through to hold it down.  Bendable does not mean foldable.  You can't roll them up either.  You will have to store it flat.  I think it would be easily damaged if carried in a Prius and would consume a considerable amount of space.

 

[myway_1]

"I think it would be easily damaged if carried in a Prius and would consume a considerable amount of space. "

I would love to be able to drive with it attached but I'm afraid that over time the velcro will degrade and the panel will fly off as I'm driving down the road.

 

[B and C]

I already mounted mine with Velcro.  I will be doing an annual inspection.  If it is to the point where I don't think it will last another year it will be time for that hair dryer, Goo Gone and a case of elbow grease so I can put a on a fresh batch.  I have to use a tall ladder to check mine, yours could be done standing on the ground.

 

[myway_1]

I wonder if I got a bendable panel with the junction box on top so that it is completely smooth underneath, if I could use a self-adhesive magnetic sheet to attach it to the roof of my car. Like attaching a magnetic decal.