Golf Cart/ Portable Power Plant

[Dualfuel]

Ha! Casey,
The cart is coming out of the snow and I am low on gas so....am definitely reviving this project. Still have not found a good 48volt charger or alternator. Still its worth going for it.

[LowGear]

Hi Dualfuel,     (Corrected Grammar)

I'm still here.  I'm still interested in your project.  I winnied out and went 36 volt because I'm sticking the batteries onto a Polaris ATV and a fourth battery would have to be much higher and mess with the center of gravity.  (the farm raises almost 300 feet in less than 800 lineal feet = serious slopes.)

Oh, we just cruised through equinox and the sun was still South of 90 degrees.  We're at 19 degrees latitude.  http://en.wikipedia.org/wiki/19th_parallel_north  and http://en.wikipedia.org/wiki/48th_parallel_north and https://www.google.com/?gws_rd=ssl#q=tropical+zone+definition[/url].

I wish the 36 to 120 inverters were as cheap as 48 to 120 inverters.

If you have an electronic voltage controller you should contact someone that is familiar with their power requirements and limits.  

Cheers,

Casey

[Dualfuel]

I will get out the compass and lay out an east-west line to see whats going on. I do notice the sun is coming in the windows on the north side of the camp.
I have the solenoid and resister controller on my cart as well. Its an old Melex (polish). I found that 36v inverters were just not available. 48v inverters seem to be the size that provides the wattage that is high enough to be useful in the field.
I have those brush piles to cut, with the electric saws, so its a lot of short cuts and setting down the saw, which is perfect for an electric.

Wow! You are south of the tropic?

[LowGear]

Aloha Dualfuel,

I do notice the sun is coming in the windows on the north side of the camp.

I'm sorry but you need a compass for sure.  At noon, when your facing the sun; you're facing South.  I'm Seattle, really close to 48 degrees, and I'll do this test today myself.

Cheers,

Casey

PS:  I found South in Kona by looking at the sun directly at noon in December.  Again, at 19 degrees and the sun isn't at 90 degrees yet.  I check this with the roof overhang and the shade line.

[buickanddeere]

Solar panel on rood will make precious little difference to the range. How many KW hr of power do you think a roof mount PV panel will generate?

[Dualfuel]

Buickanddeere,
The panels, if mounted on the cart, will produce the same kw-hr that they presently do, mounted on the building. The big advantage of mounting all the solar paraphernalia on the cart, is now the power plant can move to the wood pile, instead of loading the wood on the logging truck and driving it to the building.

Casey...ok ok, I WILL get of this comfy chair and go measure right now, as the sun IS shining in the north window, just after dawn. I will get some data for you. LOL!

[Dualfuel]

Casey...I used a lensatic compass and a GPS...at dawn the sun is coming up directly east 90degrees. The stupid camp is NOT oriented along an east west line but rather the west end is slightly northwest of the east end (hence the sun in the north window).

[LowGear]

Heyyyyyyyyyyyyyyyy,

High noon!  The change in azimuth is less influenced at the East and West as it is at the center of the path.

I'm in Seattle and the sun just ain't atop my head when it's noon.  That's the optimal time for solar generation.  This thread is about solar generation isn't it?  Before 9 AM and after 3PM are less than 25% of my total daily collection (on average). 

Of course Buickanddeere's car mounted panels would allow for hourly optimization.   

Oh well, I've got an extension to file. 

If it ain't an art project or I'm not having fun; Just what the Hell am I doing here?

Cheers,

[buickanddeere]

Buickanddeere,
The panels, if mounted on the cart, will produce the same kw-hr that they presently do, mounted on the building. The big advantage of mounting all the solar paraphernalia on the cart, is now the power plant can move to the wood pile, instead of loading the wood on the logging truck and driving it to the building.

Casey...ok ok, I WILL get of this comfy chair and go measure right now, as the sun IS shining in the north window, just after dawn. I will get some data for you. LOL!

How long do you think it will take for a roof mounted solar panel to charge the golf cart's battery bank ?

[Dualfuel]

BuickandDeere,
The charging question's answer, can vary greatly. My sense is you wish to pin your skepticism about the project on some number. Before we go there, let me explain what is already happening.
I have three panels, whose wattage I forget, mounted on the oil shed. The oil shed has a 5000 watt inverter, and enough deep cycle storage to run the pumps all day. I have had this system working in its present configuration since 2006. When I got the golf cart, I set up some long jumper cables and started charging the cart with the oil shed power, 2 105s in series at a time.
All armchair BS aside, if I mount all the oil shed solar equipment onto the cart, I expect everything to be the same, except that the powerplant in sort of portable. If I am cutting wood up on the ridge, I expect to get even more power, by keeping the panels in the sun even longer then their present location.

At present, the charge controller stops charging the batteries at about 10am. After that, the power is wasted. I used to bring the logging truck down to the oil shed and leave wood down by the oil shed for cutting after breakfast. I think it better, to take the saw, etc., to the wood pile, or take the powerplant to other projects, so I do not have to listen to the Honda droning on, all day.

Soooo, to answer the question...lets say I have no more then 300 watts worth of panels on the cart. Lets say I am charging two cart batteries at a time. Lets say I am busy and do not have any interest in checking to see when the two batteries are actually charged, so I come change the configuration once a day. Knowing that, I would say it would be three days for the cart batteries to be fully charged (the caveat being, full sun for those three days, of course).
I realize this seems inefficient. Its not. There will be a minimal monetary capitalization to get this set up. The portable configuration allows me to use wasted power in a variety of locations.
Could the efficiency be better? Oh heck yes! Efficiency comes with a price though, a price I cannot presently pay. So it is what it is.

[LowGear]

Hi DualFuel,

I'm back - in two ways.  I'm back on your thread and I'm back in paradise on the 19th parallel.  Yesterday at 11:40 the Sun was still below the 90 degree azimuth.  I'm guessing mid-May we'll go 90 degrees.  That gives a month of past 90 degree solar radiation here in the tropics.  "The Topics" is that make believe place where myth has it that at 8 AM it's Sunny and 70 degrees.

I have a neighbor with a charging ASSISTED solar panel on the roof of his Club Car. - factory unit of about 180 watts - single panel.  He isn't doing much more with his car than it sounds like you are.  Certainly nothing close to 18 or even 9 holes of golf on any given day.  He sticks it on the factory charger every once in a while to top up the batteries or if it struggles up his driveway which is not really that steep.  He gave me a "deal" on his 36 volt cart and I think I know why.  This is one of them newfangled '98 models with the electronic voltage controller so I'd have to spend a couple of hundred dollars to upgrade to 48 volts.

Charging batteries separately that are part of a string sounds like a bad date with destiny.  I'm not saying I wouldn't do it exactly the same way as you if it were working for me.  I just thought I'd mention it for those manual readers among us.

Keep you eyes pointed North and don't worry about the sun block.

Cheers,

Casey

[LowGear]

It happened sometime this week.  I checked on Cinco de Mayo and then yesterday and sometime in that week the sun's rays started striking our farm at 90 degrees.  So we'll have about six weeks before and six more weeks after solstice.  Remember the rays move from 23.5 degrees North to 23.5 degrees South during the course of a year.  And if you're farther away from the equator than 23.5 degrees North you ain't going to see the sun straight up when your facing South.

Casey

[Dualfuel]

Yep Casey,
The sun now rises to the north. I have to turn the panels to the north to catch the first four hours of light. About 10am I have to turn the panels overhead and to the south. About three I have to turn the panels back to the west and north for the remainder of the day.

[Dualfuel]

Progress

[Dualfuel]

So far I have a bench proof of concept circuit setup and am now looking for high amperage switching. I have the charging circuit setup comma and the hardest part left to do is the welding.