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Solar Chargers

reliableflyer

Registered User
Seldovia, Alaska
Does anyone have any knowledge of, or experience with charging light weight batteries such as the Earth-X or Oddessy batteries with a solar charger?

I am primarily interested in maintaining these batteries while the aircraft is tied down after a flight where minimal power has been used for starting the aircraft.
 
Odysseys work just fine. Have not tried it with the EarthX, yet. But I see no reason it shouldn't work. They were made with a circuit card built in that allows the use of standard battery chargers and the power from most solar panels is pretty smooth (not many spikes or dips).

Web
 
With the Earth-X I can go at least a couple of months between flights with no noticeable drop in battery voltage.
 
Keep the solar panel sizing down to nhttp://www.backwoodssolar.com/morningstar-4-5-amp-controlo more then 10% of battery capacity charge rate: 100 amp battery, 10 amp charge, as an example. Get a good charge controller, MorningStar is a good brand, about 30 bucks for their smallest. Don't get PV panel made for charging smart phones etc., you want something with a 17 to 21 volt open circuit capacity to charge a 12 volt battery. For your described use, I'd get a 5 watt panel, multi or poly crystalline preferred over the amorphous type.

This Idaho outfit is great to deal with: http://www.backwoodssolar.com/products/solar-panels?cat=102 This panel will outlast you, unlike the Harbor Freight type crap. The controller:http://www.backwoodssolar.com/morningstar-4-5-amp-control. Take those pertinent #'s of the controllers output, and ask EarthX, they will respond, another good company. I love my EarthX, over 2 years now, amazing lightness and great performance.
 
Simple 5w panels with no controllers work great on my Odysseys in my boats to run bilge pumps while I'm away. Never a dead battery and no overcharge problems. I'd use one on the plane if I needed to.

Does your airplane have an alternator system? You shouldn't need a "maintainer" charger for an Odyssey battery. I have equipment that I leave unattended for 7-8 months at a time and the batteries are always good unless a ghost load (like Polaris EFI) wears them down.

Costco had Goal Zero solar panels, solar lights, etc a few weeks back. Wife bought me one of their fold and go solar charging panels. I went back and bought a couple of their lights. They must use the EarthX type of battery because their melt-your-cornea spotlight weighs nothing. Very cool stuff.
 
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Stu, you might want to call Earth X after they get back from Kosh. Their booth was real busy all week

Glenn
 
Thanks Glenn.

I didn't know you read this site.

I did called Earth X and they asked me to let them know if I found a good one. They didn't have a suggestion for me.

No charging system and with Li-Ion batteries causing problems in the Jets and it being charged only on the ground while not attended, I want to be sure I don't have a fire.

Stu
 
.... I have equipment that I leave unattended for 7-8 months at a time and the batteries are always good unless a ghost load (like Polaris EFI) wears them down.
I used to have low battery problems when I didn't use my 185 for a while until I smartened up and pulled the clock fuse between flights. After that the Sears Roebuck battery would last and last and last.
 
I used to have low battery problems when I didn't use my 185 for a while until I smartened up and pulled the clock fuse between flights. After that the Sears Roebuck battery would last and last and last.

Pete,

Youre retired......don't pull the clock breaker, pull the clock.

MTV
 
Really old thread, but looking to use a solar charger.

Two questions –
If I put a panel inside can I leave it attached while using the battery? Charge/discharge/electronics issues?

And, will the green skylight cut down the charging ability of the panel?

Thanks,
Pete


Transmitted from my FlightPhone
 
One way of electrically connecting them would be to use a double throw master switch. Connect the lead from the master relay to the common (C) terminal. When the switch is 'on', this terminal will be connected to one terminal with a ground wire, turning on the master relay. When the switch is placed in the 'off' position, the common terminal is now connected to the opposite, unused terminal. If you connect the positive wire from your solar panel to this terminal and the ground wire to airframe ground, the panel will connect to the battery through the master switch, through the master relay, to the positive post of the battery. And it will only be connected to the battery any time the master switch is in the 'off' position.

Be safe and install a fuse as close to the battery as possible, just in case....

Web
 
Web, I forgot to mention I have no starter or alternator
I like your simple method through a double throw, but do I need to have the solar panel disconnected during battery use?

Pb


Sent from my iPhone using SuperCub.Org
 
No. Just use a charge controller.

Web, I forgot to mention I have no starter or alternator
I like your simple method through a double throw, but do I need to have the solar panel disconnected during battery use?

Pb


Sent from my iPhone using SuperCub.Org
 
No, you don't need it disconnected during use.

How is your power distribution set up? If all battery power comes through a switch, set it up like I described above. Use a double throw switch and connect the battery lead to the common terminal. Connect your bus to one of the other terminals for normal use. Connect the panel positive to the opposite terminal. This will give you the normal operation with the power switch in the 'on' position and connect the panels to the battery, for recharge, when the power switch is 'off'.

Web
 
Battery --> Battery Switch --> Master --> bus (2 switches). If I can find the right size panel I'll test it wired direct with a charge controller. The thought is for something to "help" during long day activities, without going to a larger/heavier battery. And, if someplace without power it can recharge on its own.

Pb


Sent from my iPad using SuperCub.Org
 
Not sure how much 'help' it will be during operation. These panels put out a pretty small charge rate. Think of it as a top charger or battery maintainer. Try out what ever set up you have in mind. Just be sure to keep that fuse installed as close to the battery as possible.

Web
 
Battery --> Battery Switch --> Master --> bus (2 switches). If I can find the right size panel I'll test it wired direct with a charge controller. The thought is for something to "help" during long day activities, without going to a larger/heavier battery. And, if someplace without power it can recharge on its own.

Pb
Did you ever consider a small wind driven generator? I have one in mind using the dynamo from a Kubota tractor. It is small similar to the B&C units.
 
Funny you should mention that. I had originally but then dismissed it. But I just saw an original on a j4 and it reminded me, although they are pretty big.
Be interested to see what you come up with.


Sent from my iPhone using SuperCub.Org
 
So far it is just an idea in my head. I do have a Kubota tractor with one of these and it is more than adequate in keeping the battery charged. And the current battery is at least 20 years old. My idea is to make a prop out of wood and bolt it to the flange on the pulley. Those two lugs provide plenty of materiel for some sort of attaching device for the plane.

This is one. http://www.worthingtonagparts.com/Kubota-Alternator-AEP-Dynamo-Assembly-NEW-WN-15531-64017
KUB-A1-TO.gif

This is the regulator. https://www.dbelectrical.com/produc...e=&network=g&gclid=CNj6i9XGv9MCFUhXDQodI8YClA I must admit that the wiring has me confused, even though I have the tractor manual. My thought is to perhaps use a B&C regulator in the airplane.
There is lots of information on line about this Kubota system.
 
To "achieve full design cycle life" the Oddysey must be charged at a minimum of 40% of the AH of the batt. So a PC925 needs 10.8 amps unless charged periodically by something stronger. This information is apparently important enough to warrant being put at the top of page 1 of the manual. Mine is Feb 2013 As with any AGM 15.0000 is your absolute top voltage before the risk of venting.
 

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That looks interesting except for the speed limitation of 110 mph and only a 4 amp output. My Cub cruises at that speed with a VNE of 160 mph and my system draws as much as 5 amps. So in order to keep the battery charged I would need a higher output. Currently I just put the charger on it at the end of the day. This process has worked fine so far but it would be nice to be able to charge in flight.
 
Yup, mine will probably be fine too, but exploring options.

I cruise at 90 and a 4 amp charge would probably equal or be less than my total draw, so it's a consideration for me where as its a bolt-on. Be interesting if you could source a prop to fit yours. Maybe even a small outboard or trolling motor prop, which are typically plastic. Testing to get the right rpm may be the harder part to accomplish without building a wind tunnel. Might have to mount the unit and fly a dozen times measuring output in flight at cruise.

pb
 
My plan is to build a laminated wood prop. It is the math calculations to figure the diameter and pitch at the different stations which I haven't got my head around yet. I worry about regulating the maximum output at higher speed to prevent causing electrical over loads. That is why I'm thinking the proven B&C regulator. I've also considered a test rig to mount on my truck to test on the highway.
 
Truck mount test would be ideal.

Would you use just the B&C regulator, or regulator and controller?
 
Yup, mine will probably be fine too, but exploring options.

I cruise at 90 and a 4 amp charge would probably equal or be less than my total draw, so it's a consideration for me where as its a bolt-on. Be interesting if you could source a prop to fit yours. Maybe even a small outboard or trolling motor prop, which are typically plastic. Testing to get the right rpm may be the harder part to accomplish without building a wind tunnel. Might have to mount the unit and fly a dozen times measuring output in flight at cruise.

pb

If you throw the Ipad out you can go all month on one charge ;-)

Glenn
 
If you throw the Ipad out you can go all month on one charge ;-)

Glenn

ha! That's quite possible.

But I did notice the Garmin radio doesn't really want to be under 12 vdc. It starts displaying "reduced TX power low voltage". Doesn't seem to affect it, but just looking for the cleanest solution. I could keep using the dewalt battery for the iPad and just use the main battery for the radio, or build a bigger box for a different battery.

I'm sure I'll fly a bunch more before anything changes, so I'll get some time to see how it works as is. I started with a battery out of the box, so next time out it'll have been recharged and may have a bit more duration.

pb
 
This is what I'm thinking.
http://www.bandc.aero/alternatorcontrollerregulator14vhomebuilt.aspx
If you look at the wiring diagram there are only two wires which come from the alternator. One to the buss and the other to the regulator/controller in addition to grounding the case. There are two wires coming from the Kubota dynamo. I'm assuming that they serve the same purpose?

Perhaps Wireweinie can verify or poke holes in the idea?

I'd be interested in his comments, as I think the controller provides additional features, but the straight up regulator may be enough for my setup.

http://www.bandc.aero/regulator14vhomebuilt.aspx
 
A solar charge controller is there to control overvoltage from the panel. Solar panels usually produce higher than desired voltage so the panel will produce an adequate output during less than ideal sun exposure. In ideal exposure the panel would cook your batter at about 17v. If your device is limited to <14.5v you won't need a controller. More sophisticated controllers will convert excess voltage into increased amperage at a useful voltage to improve the array output.
 
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