SOLAR PANEL CHARGING 3DR SOLO BATTERIES

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Hello fellow 3DR Solo pilots,

I've looked through the forum to find a thread that talks about charging Solo batteries off solar panels, but I was unable to find any content in regards to this topic specifically. Therefore, I would like to solicit fellow members for suggestions.

What solar device could be created to safely charge a 5200mAh 14.8V Solo battery?
 
Hello fellow 3DR Solo pilots,

I've looked through the forum to find a thread that talks about charging Solo batteries off solar panels, but I was unable to find any content in regards to this topic specifically. Therefore, I would like to solicit fellow members for suggestions.

What solar device could be created to safely charge a 5200mAh 14.8V Solo battery?

My whole house runs off solar. Including charging my Solo batts, but that's probably not what you meant.


All you need is a solar panel, rechargeable battery and an inverter (or inverter charger). This will allow you to charge using the standard 120vdc Solo charger. Just size the components to match your needs.

You can also drop the inverter and just charge DC to DC as long as your input voltage is ~16.77VDC. The amount of current you provide will determine how fast you can charge within the limits allowed by the 'Smart Battery'. I'll get you hard numbers if your really serious.:)

You will need to use appropriate circuit protection devices & wire gauges.

Have fun & let me know what you decide go with.
 
My whole house runs off solar. Including charging my Solo batts, but that's probably not what you meant.


All you need is a solar panel, rechargeable battery and an inverter (or inverter charger). This will allow you to charge using the standard 120vdc Solo charger. Just size the components to match your needs.

You can also drop the inverter and just charge DC to DC as long as your input voltage is ~16.77VDC. The amount of current you provide will determine how fast you can charge within the limits allowed by the 'Smart Battery'. I'll get you hard numbers if your really serious.:)

You will need to use appropriate circuit protection devices & wire gauges.

Have fun & let me know what you decide go with.

Thanks for the reply, I'd prefer to purchase something that is prebuilt. Would the Powerfilm Solar 120W foldable Solar charger meet the needs for the solo batteries?
 
Actually, that solar panel's specs are not too bad. Still it's questionable it will completely charge your Solo's battery(s) as the solar panel has a listed operating voltage of 15.4vdc and the Solo's 120vac charger has a measured no-load voltage of 16.77vdc.

Also keep in mind that the website recommends using a battery in place of direct charging (for laptops which use similar batteries to the LiPos for your Solo). For these reasons I cannot recommend the solar panel you listed, but if you do get one please post your results here. I'm sure others would benefit from your experience.

Best of luck to you & clear skies.
 
If I were to do this, I'd use a CC/CV DC-DC boost converter, which are about $7-15, and not use the 3dr charger.

Solar Panel (~15V) --> DC Converter (boost to 16.8V and limit CC to no more than 6A) --> Solo Battery.

The solo battery, when depleted, will draw 6A to start and rapidly decrease as it charges. It probably drops to 5A after about 5 minutes. So the power required to charge it drops rapidly with a pretty high load up front. You have to limit the charge to 6A though. Anything higher will cause the battery to turn itself off.

This panel, assuming OPTIMAL sunny conditions, can provide about [email protected] (~117 Watts), which is adequate for charging a solo battery. It would charge a totally depleted battery in about an hour (30 minutes faster than the stock charger). Again, assuming optimal conditions. Anything less (cloudy skies, etc) will still charge the battery, but just slower.

The best setup though, would be to use the solar panel to charge a 12V car battery, and then charge the solo off that battery, using the car battery as a buffer and also to store more energy. It could be charging all throughout the day while you're out and about. But I'm sure you don't want to lug one of those around :)
 
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If I were to do this, I'd use a CC/CV DC-DC boost converter, which are about $7-15, and not use the 3dr charger.

Solar Panel (~15V) --> DC Converter (boost to 16.8V and limit CC to no more than 6A) --> Solo Battery.

The solo battery, when depleted, will draw 6A to start and rapidly decrease as it charges. It probably drops to 5A after about 5 minutes. So the power required to charge it drops rapidly with a pretty high load up front. You have to limit the charge to 6A though. Anything higher will cause the battery to turn itself off.

This panel, assuming OPTIMAL sunny conditions, can provide about [email protected] (~117 Watts), which is adequate for charging a solo battery. It would charge a totally depleted battery in about an hour (30 minutes faster than the stock charger). Again, assuming optimal conditions. Anything less (cloudy skies, etc) will still charge the battery, but just slower.

The best setup though, would be to use the solar panel to charge a 12V car battery, and then charge the solo off that battery, using the car battery as a buffer and also to store more energy. It could be charging all throughout the day while you're out and about. But I'm sure you don't want to lug one of those around :)


Thanks for the input. The idea with using the solar panel is that I need it to be lightweight. Hiking 11 miles one way along the Kauai coast makes the car battery idea suggestion not feasible due to weight restrictions. The intent is to go ahead and purchase this solar panel and see if it works. In the following months I will post my progress.
 
Thanks for the input. The idea with using the solar panel is that I need it to be lightweight. Hiking 11 miles one way along the Kauai coast makes the car battery idea suggestion not feasible due to weight restrictions. The intent is to go ahead and purchase this solar panel and see if it works. In the following months I will post my progress.

Wow Kauai is absolutely gorgeous! Maui too! Did they ever build a road that goes around the entire island (Kauai)?
 
You should be able to use some Goal Zero solar gear with a DC-DC step-up converter as in this thread (DIY Multi Battery Charger) Their Sherpa 50 power pack can put enough juice at 12v to feed the converter (and Solo battery), just match it with one of their panels and some kind of case to protect the DC-DC converter (it gets HOT). This will probably be the lightest and most efficient option you can go with, it omits the 3dr 110v charger, an inverter, and the AC/DC conversion losses.

Oh, and enjoy the Kalalau Trail! I can't wait to see the pics and video you capture of the Na'Pali Coast! It is definitely one of the most beautiful places on earth! (Don't underestimate how much water you'll need for that hike, or how sketchy the trail can get if weather moves in)
 
Maloy,

Are you camping out during the hike , if so how many days ?
If one day hiking, carry more batteries and forget the solar panel.

Before you spend like US$1,200 + needing to do some electrical work, best to make a charging flow chart.

Your choosen brand :
http://www.amazon.com/PowerFilm-R-6...5430052&ref_=sr_1_22&s=merchant-items&sr=1-22

First and foremost, any solar cell loose its power rating above 25C solar panel temperature.
Ask the manufacturer its datasheet and its temperature coefficient
Solar Panel Temperature – Facts and Tips
Hawaii sunny sky, expect your solar panel temperature to hit easy 65C in 30-45 minutes, calculate the loss. The good news is 120 watts version even with reduction would be decent juice to charge the solo battery. Make sure no part of the panel get shadow. Shadow is not a tiny bit power loss matter, its a disaster.
Simple one :
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Technie one : http://www.nrel.gov/docs/fy09osti/46001.pdf

Because the solar panel you have in mind is flexible , its very expensive per watt. Today its about US$4 per watt for branded cell non flexible, approx.
Your choosen one cost like US$10/watt.

Check the Solar radiation map of Hawaii, the region you will be using it
Solar Radiation of Hawaii | Interactive Map
http://files.hawaii.gov/dbedt/op/gis/maps/solrad_kauai.pdf
Annual Days of Sunshine in Hawaii - Current Results

Test your battery from empty to fully charged, how many hours using Solo OEM charger ?
As Steve pointed out, you can not charge any faster than what the Solo's battery controller chip will alow, assuming you have sufficient power supply.
All this charging limitation is the battery chemistry actually, its given.

Do the math : how many batteries you can charge a day based on the sunny sky at your location , this is max charging as in perfect condition and you probably will not get that.

Your Solar panel weight + charging accessories , the 120 watts model, panel only is equal to 6 of Solo's battery because its 3kg and Solo bat is @500grams.
Unless you camp for a few days, forget the solar panel idea and buy more batteries :)

Safe hiking..........

.
 
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