Solar Lithium Ezgo

EzgoSun

New Member
My project is to refurbish a 1996 Ezgo TXT, 36 Volt, with the plans to put a very large solar panel on top with the end goal of having an electric cart that is charged by the sun completely and is powered by Lithium batteries. I grew up around golf and rode in a few carts over the years, so am sure the golf memories will come, once its complete. This cart will not see a golf course, but a remote ranch in the southwest USA where we have 300+ days of sunshine and no utilities.

The project cart came with out batteries, and 3 - 75 w 12V nominal solar panels mounted on an aluminum frame above the roof.

So now I will chronicle the progress.....

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HotRodCarts

Cartaholic
Interesting project. I'm looking forward to see how the solar powered charging works out with the lithium batteries.
 

EzgoSun

New Member
After a trip from the carwash and into the shop, we installed a 6 inch lift kit in prep for custom 12" rims and aggressive tires. My background is more mechanical so we worked on that first.The floor mat was removed to find 3/4" of clay mud under it over the years and the floorpan rusted.
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Paint it or replace it. ??? Replaced it with aluminum diamond plate. (Then would get the mat back in place)
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From the looks of the battery frames they are rusted and corroded but serviceable.
Next would be a hitch to pull wagons around...
What to do with the steel pickup bed on the back? The piano hinge is so weathered and rusted it won't open. Soaked it in PartsBlaster penetrating oil for days. At last broke it loose.
What if it tilted to dump stuff from it?
 

EzgoSun

New Member
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Hinge fabrication

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Latch fabrication

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lift spring struts to raise once handle releases the latch. Rebuilt the frame from 3/4" x 1.5" rectangular tubing. You have to put considerable weight on the bed to push it back down to latch. Rubber bumpers keep it from rattling. Too you can see the new wheels and aggressive tires from the stock ones. Two weeks later of fabrication trial and error, the bed project was mounted and primed. ( I tried to post a operation video without success )
 

EzgoSun

New Member
From Loyd-ss

"Hey EZGoSun,
Sounds like a great project and the solar charger will be the icing on the cake. The records from my cart showed an average consumption of 135 watt hours per mile.

( this is very Encouraging Loyd-ss!! , I thought it would do well , but didn't have a clue on consumption numbers)

If you can get 5 hours of sunshine a day ( don't know where you live so might be way off) that could be 1740 watt hours per-day (5 hrs x 435 watts x .80 efficiency) or almost 13 miles a day. Sounds darn good.

These would be conservative hrs for my region, maybe even winter hours here.

Does the solar panel feed into its own combo control box and battery charger?

Yes, I have selected a nominal 48v output , 100V max solar input, 20A Victron Mppt charge controller This controller is to have Bluetooth to connect to my phone.

I am assuming that it will put out the correct voltage for the battery modules to charge the batteries directly?

Yes will have options to customize battery charge settings

Monitor the first charging cycle carefully, but first verify that all cells start out at the same voltage. There are 4 cells in each module, set up as 2 in-series cells connected in parallel to 2 more cells in series. Recommended max charging voltage per cell is 4.05 vdc, or 8.1 vdc per module. If they are uneven, top them up (or discharge any that are overcharged). The reason it is such a big deal to keep the voltages even is because these batteries get permanently damaged if outside their operating range of 8.14 VDC max per module and 7.0 vdc minimum. Since your solar charger will be putting out up to 9 amps at 48v (maybe) it will need to be monitored by you, or a BMS.

Ultimately by BMS , yet I have not ordered that yet. I haven't been able to get time to determine how I will mount the 7 Nissan Leaf G2 modules. The BMS I was looking at during Battery purchase may not fit if battery modules are not all secured together . Work and obligations take precedence. winter weather is not as comfortable in the shop.

The charge and discharge curve of these batteries is very flat in the middle operating range (50 volts to 56 volts), so you need to closely monitor the first charge or 2, till you get confidence in the design.
Good deal!
Please keep us informed!

Started a new thread at last.

Lloyd"
 

EzgoSun

New Member
Well as I jump ahead in progres the cart is now a 48v system, the wiring, motor, controller, soeinoid, Reverse / Forward all upgraded to 2014 vintage. The old wiring was well old, and brittle. This project needed to be reliable.
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All that was left was key switch, buzzer, throttle pedal.
I had hoped I would make up a pigtail, to go from old throttle plug to new controller 4 wire connector, yet have been unable located the matching connectors
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EzgoSun

New Member
Seat is now recovered this weekend. - Solar Charge Controller arrived, yahoo.

Original seat cover was stained, dry, and punctured, with a rotten plywood bottom, fasteners rusted beyond use. Replace the plywood and pressed in new nuts for side handles.

HF 20 ga pneumatic staple gun w/ stainless steel t50 staples, and a heat gun made all the difference in smoothing out the corners with a taught stretch of the vinyl. Once the original cover was removed, it appeared to be molded into shape and wasn't sure if I would end up with pleats at the corners. Warming the vinyl and stretching it made all the difference. I purchased a heavier UV grade vinyl, and skipped sewing on designs in the cover, added 1mil plastic under the vinyl to keep out moisture from getting into the seat foam. Am looking forward to getting the rest of the seat pieces back together.
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Holiday week coming up and will have to delay getting humpty dumpty back together.

Solar Charge Controller is here! After 2 suppliers and a special order at last we can move forward.
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EzgoSun

New Member
Can I give you my seats That looks better than factory
Can I give you my seats That looks better than factory
Diode , thanks for compliment. After the pics were taken I was wanting to cover them to keep them new, which really was not the point of this project. Mud and dust will be the norm soon.
Yes would be happy to help / teach upholstery methods.
I know those of you reading this thread are wanting the solar application details, I am too. We are getting so close. Enjoy your Thanksgiving.
 

EzgoSun

New Member
Update:
Well I am getting closer to moving the cart to the remote ranch. Rolled it out of shop to get a picture to share concept with friends back in the early spring. And am at last working in earnest on it now.

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Its not the prettiest cart, but should be quite functional for working on a ranch with no electricity in the rural south west.

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Battery pack temporarily set in for testing, am getting eager to test it, since I have never had it run on its own since purchased in the fall. We worked late into the night to get it going with no luck. :thumbdown:

Next day- "hot" wired the charge disable wire to the controller and wheels started turning. YEA! I wasn't expecting to use the charge plug so hadn't worried about wiring it up.
1st Milestone : It RUNS!

We have driven it maybe 1/2 mile total and am pleased to have it GO.

The steering & spindle bushings are shot, so, its back in the shop for repair to front end of this 1996 EZGO TXT.

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Solar charge controller with bluetooth app for reporting / monitoring.

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First charge after sitting in the shop and a few trips down the driveway!
2nd Milestone - Its CHARGING ! ....

It charged for 52 min and raise voltage 10V (42V - 52V), looking good, feeling better to get some current into the low batteries. Went to lunch for 30 min expecting it to be fully charged when I got back and it had all but stopped at ~53V. slowed down to a craw at 6 watts in full sun. Its as if the charger overheated and stopped it bulk charging, or I have some unknown settings way off. I'll have to wait till front end is repaired to get it back out in the sun, as its on jack stands. First couple of attempts to resolve the settings on the charge controller have led know where from my supplier, as the software is using lead acid battery terms they are familiar with. Default Lithium settings didn't accomplish full charge. Sadly I don't have all the instrumentation set up to monitor each cell yet to understand the bms operation as it was charging.

2 steps forward .... 1 step back..
 

EzgoSun

New Member
Front End bushings:
Hmm... the steering arm bushing is badly worn so will order that.

The spindle bushings are worn too. I am not seeing many being offered. 7/8" od, 3/4" id and aprox 4" long. I believe they have to be reamed once they are pressed in ?
Will the newer style with short bushings top and bottom work as well?
The front lift kit axle has slop in the holes for the 3/4" king pins as well. I don't know if its poor manufacturing or if the new short bushing will fit in and close the gap.
Any suggestions are welcomed.

too in looking at the tie rod ends, they are stiff. maybe these too.
shocks ? maybe.
 

HotRodCarts

Cartaholic
I've been wondering how things were going on your lithium battery solar powered conversion, Thanks for the update.

As far as the spindle/king pin bushings it depends on the drop axle lift manufacturer. Usually they use the stock bushings so you should need the pre 2001 bushings.
 
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