Solar setup for a golfcart

[Jalapeno_prepper]

I have a 48V EZGO golf cart. Anyone done an install with a solar panel on the roof and charge controller to keep my batteries topped off free of charge by parking in the sun.

 

[TCgreg]

Sounds like a fun project. If your battery bank is 48v you will need a solution with high voltage panels. The roof space might be a limiting factor. Perhaps a pair of 24v panels connected in series. If they overhang the roof a little it shouldn't matter. Golf carts have a sizable battery bank so charging would be slow to fully charge a drained bank but if you are regularly parked in the sun and only partially depleting the bank occasionally it should work fine or at least reduce your plugged in time.

 

[eddie1261]

Wouldn't it be the perfect irony if he DIDN'T use 6v golf cart batteries?

 

[Gary]

I'm looking to do the same thing on a 6 passenger cart. I have 6 8v lead acid batteries. I think I found the components to help get a little more distance but would love some input from someone with actual knowledge. For a panel I was thinking 1 Renogy 270 watt 24 volt panel with a Genasun GVB-8-Pb-48V, GV-Boost 8 Amp 48 Volt MPPT Solar Boost Charge Controller for Lead Acid Batteries to get the 24 volt panel to match the 48v system. Does this make sense?

 

[Jalapeno_prepper]

Yes I just read up on those boost controllers. I need to read up more on them. I also seen 48V panels for sale on Amazon for ridiculous prices from 475-900 dollars.

 

[Gary]

The Renogy panel is $250 and the booster is $150 on Amazon. With 10awg wire the whole system should come in just under $500. That is if my idea would even work?

 

[GinoMaid]

It seems to be a fun project.

 

[eddie1261]

Do it! We are all dying to see this done. And somebody else pay for it....

 

[Delmar]

I am planning to do the exact same thing with four HQST 100W panels totaling 48V. Assembled size will be 71” long x 52” wide, will only overhang the roof by a few inches.

Is a charge controller really necessary? While the cart is solar charging it will either be moving, or stationary connected to my APC 3000XL upsverter. There is not enough sun in a day for 400W of solar to overcharge 200AH of batteries, even when idle.

 

[SolarRat]

Is a charge controller really necessary?

Yes, even if it's a $10 cheapy it's better than nothing. Should be easy with 4 panels but they will overhang your top by a lot.

I'd use a single 60"x40" 300w+ through a boost CC though. I bought one of these from Aliexpress for $30 to try out...

Amazon.com : Fuhuihe MPT-7210A Charge Controller Battery Solar Panel MPPT with LCD Display for 24/36/48/60/72 V Battery : Garden & Outdoor

Amazon.com : Fuhuihe MPT-7210A Charge Controller Battery Solar Panel MPPT with LCD Display for 24/36/48/60/72 V Battery : Garden & Outdoor

www.amazon.com

 

[Delmar]

Yes, even if it's a $10 cheapy it's better than nothing.

Since I’m a solar newbie (as with others here) would appreciate the education why is necessary. I planned installing a blocking diode to prevent backfeed, and manual disconnect if/when the batteries are fully charged. The UPS will auto shutdown if the battery is overly discharged.

 

[JeepHammer]

25 or so years ago I started with automotive batteries, cheap panels and it went like you think.

I was on the hunt for actual deep cycles and ran into a guy selling *almost* new GCs, 48 volts worth.
The 'Hitch' was I had to haul the old golf cart they were in off and dispose of it since it 'couldn't be fixed'.
The guy bought a big new golf cart but kept the old charger...

SO...
Just out of curiosity I checked the wiring, replaced a solenoid with the correct voltage solenoid, and the cart took off!
So now I have a 48 volt battery bank that's MOBILE!

Cobbled together solar panels for the 'Sun Shade', used a little creative wiring to charge the cart off existing panels, and power up the homestead, what little there was of it...
Creative wiring and I could stick or MIG weld off the batteries.
An inverter, extension cord and cord reel and I had power for common 110vac tools.
(Anyone remember what cordless tools were like 25 years ago?)

I even added an air compressor and hose/reel.

As for around the homestead and down the county road, making laps back & forth to work (350 yards) it's about perfect.
Now, other than tires, occasional batteries, a couple of wheel bearings and another power solenoid (or maybe to?), motor brushes. No gas, no oil changes, etc.
It's been about the same trouble as my framing hammer, and hammers are pretty darn reliable!

The more complicated suspension and add-ons will require more maintenance, proprietary parts.
If you intend to run it a LONG time, simple is a gift.

Keep in mind it's not a high voltage AC motor, it's not a long distance vehicle or fast.
It goes through pastures and fields NOT digging them up like a full size vehicle will.
I have a lawn mower trailer I keep the general field/garden tools, welding leads, etc in so they go under roof easy and that's worked out very well.

It's quiet, you can drive up on deer, we often have been right on top of them before they saw us.

It's worked out well for us, and it's still around. Looks like it's been through a war, but with the turn of a key it takes right off.

 

[SolarRat]

Since I’m a solar newbie (as with others here) would appreciate the education why is necessary. I planned installing a blocking diode to prevent backfeed, and manual disconnect if/when the batteries are fully charged. The UPS will auto shutdown if the battery is overly discharged.

Your 400w isn't much, but it can charge 48v at 8 amps, which isn't nothing...so it might take a few days but it will fully charge those batteries. You don't want to overcharge them if you forget to disconnect. Also, the battery will be charging in the neighborhood of 76 volts with those 4 100w panels in series...which is obviously not good for a 48v battery.

El Cheapo charge controllers can be had for under $10, so it makes no sense not to use one, unless you don't mind buying new batteries every few months. I'd strongly recommend spending more for a better one though.

I have a small 15w "12v" panel attached directly to my small tractor's battery because the battery doesn't hold a charge anymore. Now it always starts right up even after sitting for months, but the battery has a surface charge of over 16v at all times. Somehow it hasn't blown up, but it sure as hell won't hold a charge for more than a minute by itself anymore.

 

[nibs]

Just slightly off topic.
My garden tractor has a golf cart motor and 4 - 6V golf cart batts @24V. Put a 300 watt solar panel for a roof, and in two years now, have only had to plug in my tractor to the charger once when heavy use combined with a cloudy week. I use a $10 controller and could not be happier unless I had LiPo batts. (am saving up to get them). Have no idea what the range is, but did have it in the town parade and did 5 Km with a loaded trailer for about 3Km of the way.

 

[Delmar]

Bought the MakeSkyBlue MPPT on Amazon for $77. The 30A capacity should allow adding a 2nd set of 400W panels for extended power outages.

 

[SolarRat]

Bought the MakeSkyBlue MPPT on Amazon for $77. The 30A capacity should allow adding a 2nd set of 400W panels for extended power outages.

I was looking at that one or the similar PowMr for my 36v boat. Please let us know how it works when you get it all hooked up!

 

[Delmar]

I understand the PowMr is a copy of the MakeSkyBlue. There are also counterfeit FakeSkyBlue units sold by Amazon, will report when I receive. Figured if the MakeSkyBlue is good enough to be copied then it must be decent! Redneck logic...

 

[SolarRat]

I understand the PowMr is a copy of the MakeSkyBlue

I heard the opposite. Either way, they are both probably cheap copies of something else. I was only interested in it because of it's adjustability (36v range). My options are limited at that voltage.

 

[Delmar]

I bought one of these from Aliexpress for $30 to try out...

Amazon.com : Fuhuihe MPT-7210A Charge Controller Battery Solar Panel MPPT with LCD Display for 24/36/48/60/72 V Battery : Garden & Outdoor

Amazon.com : Fuhuihe MPT-7210A Charge Controller Battery Solar Panel MPPT with LCD Display for 24/36/48/60/72 V Battery : Garden & Outdoor

www.amazon.com

1. Why are you looking at the PowMr if you bought the Fuhuihe?
2. Did you attempt to input a 12V panel to the Fuhuihe and boost-charge your 36V bank? Could connect my car at night to charge my 48V bank, or during a hurricane where the sun might not be out for days.

 

[SolarRat]

1. Why are you looking at the PowMr if you bought the Fuhuihe?
2. Did you attempt to input a 12V panel to the Fuhuihe and boost-charge your 36V bank? Could connect my car at night to charge my 48V bank, or during a hurricane where the sun might not be out for days.

It's for a totally different project. I'm using it to make a variable benchtop charger. I'll feed it with my 12v 30a power supply and be able to charge my 4s,6s,7s,10s,13s and 14s lithium packs with it. It's the most versatile cheap device I can find to make a variable charger. If it doesn't work well as a bench charger, at $30 on Ali-Ex it's still handy to have around in case I ever needed to charge my boat or whatever off just one panel. Or like you said, charge your bank off your car alternator. Only problem for a large bank is that it's only 10amp, so it'll take a while (but multiples can be hooked in parallel).