Another Golf Cart Question

dhertzel

I want to provide power to the carport where I will store and charge my golf cart, and my options appear to be to dig an 18" trench about 100 ft through very hard ground (jackhammer required) or put a solar system on the carport. A thread from 2011 suggested that digging the trench was the more economical option, and I'm wondering if that's still the conclusion today. The cart has six 6-volt batteries and currently charges through a charger that plugs into a standard 110v outlet. I don't use the cart very often or long, but it's a necessity to maintain the irrigation on my 3.5 hillside acres. Thanks for your input.

Cariboocoot

Re: Another Golf Cart Question

Welcome to the forum.

Your batteries are probably standard GC2's: 220 Amp hours.
Normally that would require a minimum of 11 Amps @ 36 Volts or 514 Watts. Check your charger for exact specs if you want full recharge from solar. You could also minimize the solar to a maintenance level.

The charge controller is limited because many of the inexpensive off-the-shelf controllers can't be set at 36 Volts. You'd be looking at a TriStar 45, for example: http://www.solar-electric.com/trts12vochco.html Pretty large capacity which you'd be using less than half of.

You can do it with three well-isolated 12 Volt controllers, plus 12 Volt panels, but that can be expensive too.

Or you can power up an inverter and use the existing 120 VAC charger, which is somewhat less efficient that running DC direct. In that case you would also need to know the charger specs so that its power requirements are met.

If we know how much power we're trying to get we can cost out some different ways of doing it and then you can compare that to running a line.

dhertzel

Re: Another Golf Cart Question

Thanks. I'll check the specs when I get home and come back with the details.

mike95490

Re: Another Golf Cart Question

Will any of the Midnight Kids run at 36V ?? The problem with the morningstar is no meter, which is an extra $100

vtmaps

Re: Another Golf Cart Question

mike95490 wrote: »

Will any of the Midnight Kids run at 36V ?? The problem with the morningstar is no meter, which is an extra $100

Take a look at the Genasun controllers. They specialize in golf cart chargers and have controllers that can charge a 36 volt battery with a 30 volt panel.

dhertzel,
maybe you could just put a small solar maintainer system at the carport. After using the cart, pull it up to your house for a charge off the grid. Then put it in the carport and let the solar take care of it.

--vtMaps

dhertzel

Re: Another Golf Cart Question

Thanks for the additional input. The maintenance system might make sense, but I'd still be interested in what full charging would require.

In response to Cariboocoot's questions, the batteries are GC2S (did I need to check the amperage too?) and charger specs say:

Input: 120 VAC, 60 HZ, 9.5 A. A.C.
Number of Cells: 18
Ampere Hours: 245
Output: 36 VDC - 21 AMPs

I'm a decent do-it-yourselfer, but I'm a complete novice in this field. Thanks.

dhertzel

Re: Another Golf Cart Question

Oh, I guess the picture I took did attach. Wasn't sure it would.

westbranch

Re: Another Golf Cart Question

without using a calculator, that charger puts out ~ 740Watts, so roughly you will need >= 1000Watts of panels to supply that power, at its max draw... plus CC , all to do a float charge....??? Thats a fair chunk of change for a long extension cord...

dhertzel

Re: Another Golf Cart Question

Ok, I hear you. What about a maintenance system? Ballpark cost?

Cariboocoot

Re: Another Golf Cart Question

dhertzel wrote: »

Ok, I hear you. What about a maintenance system? Ballpark cost?

Maintenance is much easier as you only need about 2-3 Amps.
Cost gets tricky because small panels cost more per Watt.
One way to do it: Three 12 Volt 45 Watt panels like this: http://www.solar-electric.com/spm040.html $137 * 3 = $411
And three small charge controllers like this: http://www.solar-electric.com/sg-4.html $30 * 3 = $90
You're at just about $500 there.

Tobit

Re: Another Golf Cart Question

Cariboocoot wrote: »

Cost gets tricky because small panels cost more per Watt.

Even when factoring in shipping? There are many places on the west coast where you can get 200W+ panels for less than $1/watt. However, to ship them here in the North East, many of the west coast distributors quoted me close to $400 in shipping alone. There are several places, Renogy, for one, where you can get 100W mono panels for $150 with free UPS delivery. I have two Renogy 100W poly panels that work great. Sure they aren't Kyocera or some other well known brand but I haven't had any issues with them.

I was lucky when I found Solarworld 275W panels for $1.22/watt delivered.

Cariboocoot

Re: Another Golf Cart Question

Tobit wrote: »

Even when factoring in shipping? There are many places on the west coast where you can get 200W+ panels for less than $1/watt. However, to ship them here in the North East, many of the west coast distributors quoted me close to $400 in shipping alone. There are several places, Renogy, for one, where you can get 100W mono panels for $150 with free UPS delivery. I have two Renogy 100W poly panels that work great. Sure they aren't Kyocera or some other well known brand but I haven't had any issues with them.

I was lucky when I found Solarworld 275W panels for $1.22/watt delivered.

Yes; large panels cheaper per Watt but more for shipping on individual panels. Switch it to buying a pallet and the economics swing back. But of course with 'GT style' panels you also need more expensive MPPT controller.

You can just about go mad trying to get the best deal these days.

Panels like the Renogy or Solarworld aren't going to work in this application as singles because their Vmp is not high enough to charge a 36 Volt battery bank. So the smaller, more-per-watt panels work out better for maintenance charging. If you were to go for a 'full charging' system the economics would swing back the other way.

dhertzel

Re: Another Golf Cart Question

Much belated thanks for the updates, guys. I'm gonna see how much it costs to dig a trench for the conduit, and if the maintenance option still makes sense, I'll ask for a little more specifics on how to do it.