Solar for golf carts
 

If you have an e-golf cart and the typical acid/lead batteries, you probably shouldn't use a solar panel on your cart. It takes to a lot of energy to charge those 4, 6, or 8 deep cell batteries and the trickle from the solar panel wouldn't be measurable. It would be better to install a switch to totally disconnect the batteries when not using for a hour or more. I have noticed that on my Tomberlin e-cart, that when I turn the switch off the batters bounce back and maintain a charge longer. For some reason, the cart uses energy even when at rest.

Yes, I was able to reach Jimbo. Thank you very much. -myk

Does it take days of charging before that 70 mile drive or how does that work? I honestly didn't think there was that much energy in a few square feet of solar panels....but I would like to be wrong!

the energy is in battery bank not the panel.

Also the point of going that far was a test, in real life you might go 25-35 miles in one day

Beyond that any cart will get uncomfortable sitting in that long

Thnx sanibel40. I am aware that my e-golf cart power gauge goes up after I switch off for awhile. Example, if it was at 90%, then I switch off for 30 minutes, the power gauge goes back to 100%. But I also noticed after that 2nd time switch off switch on, the power goes down faster. Therefore, I think the idea of power “bounce back” is misleading which is why I wanted a solar to EXTEND the charge or the range of the batteries. After all, it is almost always sunny in The Villages, and the e-golfcart is almost always outside. Have you actually tried measuring how long it will take trickle down charge from solar to the batteries? Anyway, I will give it a shot with the help of jimbo who was in this thread. One of my super power is to do something that said it cannot be done.. although obviously jimbo had done it. I will let y’all know the result. Thank you, -myk

Respectfully you are incorrect:ohdear:

The most I’ve traveled via my golfcar was about 35-40 miles: Drove from Pine Ridge to Palmer Legend, played 18 holes driving my golfcar, drove back home to eat lunch. Then drove the golfcar to Cane Garden & played another 18, then drove back home. That’s with a passenger with his golf bag/clubs too. When done, the battery gauge is at 24%. Most likely the longest I will be driving the golfcar in a day although I still wanted to drive to Brownwood Square that evening which would’ve added another 12 miles round-trip. As I’ve been saying all along, I just want the solar panel to extend the range of the batteries; not as a replacement nor to charge fulltime. Thank you, -myk

I installed a system last year. Flexible unit, taped it to the top (dbl stick 3M) ran the wires to the charger box (comes with the unit). The max output is 100 watts which isn't a lot but if you park in the sun for several hours you will notice a change, although I can't qualify the amount.
Easy install. Worst is removing the top. I put mine on a Club car Precedent

Hi Ezridermd. Thank you for the info. Question: Caught my eye when you said “if you PARK in the sun...”, does that mean the solar aren’t charging the batteries while the golfcar is running? I apologize if that’s a stupid question. I know zero regarding solar panels which is why I post the original thread in the first place. Also what golfcar and type of batteries do you have? Thank you, -myk

Flex panels are not that efficient I think they lose 30-40% so 100 watt is about 60.

As you drive (in the sun) the volt meter increases, showing a charge, driving under say a tree the meter decreases indicating decrease from the bank.

I drove from Brownwood to Spanish Springs and back and see this happening all along the way.

I use a real glass panel

Your charger is 1750 watts to charge a set of batteries to full charge. Ive never seen a solar panel that can fit on the roof of a golf cart that is 1750 watts.

Whatever the wattage is for a solar panel, that is in perfect setting, so decrease its rating by at least 20 percent, then take into account that your not getting full effect of the sun all day long even here in florida. They have charts for the whole country as far as what you can really expect to see with the use of a solar panel as far as charging anything.

So I agree, take any solar panel and take 40 percent right off the top as far as what you are really going to get. Is it going to charge a golf cart to a full charge? The answer is no, as there is not enough "push" to full charge a deep cycle battery. Solar for golf cars has been around since the mid 1980's, so its nothing new. It still doesn't work as some say it should.

Kenny, I speak from experience first hand please don't mis state facts,

they work great the loss on good panels is 17%, and yes it will fully charge a bank with no problem.

It's 40% on flex.

THere's plenty new for those with an open mind

The actual numbers are as follows:

Assume a 6x8volt Trojan battery pack: total energy of the pack is 8.16 kWh. The number would be higher for a 8x6volt configuration. You can use the actual energy capacity of your pack if it is different.

Assume a 300 watt nominal solar panel: the average energy per day that the panel can generate if the cart is left outside all day unshaded would be about 1.2 kWh. This is essentially the integral under the solar curve for an average day in Florida. In the summer, it would be higher, in the winter it would be lower. For a lower rated panel the number would be less.

Therefore, you could take an essentially empty battery pack to full charge in about 7 days ignoring charger inefficiencies and if the cart was left idle and outside all day. Another way to look at it is you can gain, on average, 6-8 miles of range per day if you left the cart outside all day. Or, if you are only driving the cart 6-8 miles per day and you left it outside all day then you may not need to ever plug it in (energy in equals energy out) if you started with a fully charged battery pack. Of course, the cost of plugging the cart in if you are driving 6 miles per day is only 12 cents per day. And there is the rub; for the cost of a solar panel you can drive 6 miles per day for 14 years plugging in at home using SECO.

265 watts at noon on a perfectly sunny day at the equator

A 265 watt panel at our latitude here in TV would generate about 230 watts at noon on a perfectly sunny day mid-spring and mid fall. At the peak of winter that value drops to 160 watts because the sun is at 53 degrees from perpendicular. Cloudy days kill these values. Obviously, these numbers diminish to zero before and after noontime as you approach sunset/sunrise. Additionally, most commercial photo-voltaic cells lose between 1% and 2% efficiency per year so put that into your calculation as well.