Solar Panel for golf cart

[pea33nut]

I just purchased an electric golf cart and thought about putting a solar panel on the top. This cart has 6 6 volt batteries. I know very little about solar so I am wondering what I will need. I looked on ebay and found the following.

50 Watt Mono Crystalline Solar Panel UL CE - USA -
60 Watt Solar Panel 12Volt UL Grade A 60 Watt Low Price
80 watt monocrystal solar panel 12 volt systems

Any ideas on what I might be looking for?

[SteveC]

In my varied collection of PV panels in our array, I have a 125 watt [12 v] panel which was designed to be a golf cart roof. The frame is plastic [fiberglass??] and has holes for attachment to the roof frame, etc.

Meaning, if I have one, they are or were available when I bought mine. I did not get it for a golf cart, a supplier I was dealing with bought a bunch of them from some factory and was selling them off.

[russ]

If you want solar for your cart you are far better off with a fixed array to charge your batteries at night when the cart is parked.

The amount of panels you can get on top of the cart won't do you any good.

Russ

[pea33nut]

Say I wanted to mount one of the roof how many volts per hour would charge on average. If I left it outside all day for two days would I get a full charge?

If you want solar for your cart you are far better off with a fixed array to charge your batteries at night when the cart is parked.

The amount of panels you can get on top of the cart won't do you any good.

Russ

[Mike90250]

12V @ 125 W = about 7 amps delivered to the battery.

6, 6V batteries generally means a 36V cart. Assume batteries are 200ah, a common size. The battery bank is therefor 7,200 watt hours. HALF charge is 3,600 wh.

Your panel is about 100W when normal de-rating is applied, like the automotive gas mileage stickers. (sticker says 35 mpg, you get 26mpg)

So to take a half charged battery to full, would be 36 hours, or in 5 hour solar days: over 7 days. That's beyond the 24 hours where the plates begin to sulfate and ruin the battery

As was said before, a 2KW Grid Tie installation, would put power into the grid, and you can use it back at night for recharge.

[Sunking]

Peanut you are wasting your time and money pursuing this idea, physics is just not with you my friend. I have 2 golf carts, one is a racing electric cart, and I am an electrical engineer...

Here is the problem, well actually a couple of problems. The panel Vmp must be up around 54 volts for a 36 volt cart. Good luck finding one. They are available from specialty after market manufactures for a very special price that works for them very well.

Ignoring the voltage challenge is plain ole simple math and physics. At the very best you can fit a 200 watt panel on a cart for around $1000, plus you will need a charge controller for another $300 or so. Otherwise the panels that are affordable are about 125 watts, and a cheap CC for around $150. But what does it buy you? Almost nothing!

Golf cart batteries are pretty much discharged to 50% or more DOD. One should never exceed 50% but most folks are ignorant about that. OK at 50% DOD using the 200 watt high dollar model it will take you roughly 10 days of full bright sun to recharge your battery in the summer and up to 4 weeks in winter months.

I do not know about you but I consider that completely useless, waste of time and money. You spend around $1000 to $1500 to generate less than a dimes worth of electricity. Get you a good 3-stage golf cart charger, plug it in for 8 hours and forget about solar.