Electric golf cart

So, I have dreaming about this idea for years. This year I finally got moving. I am building a solar powered golf cart (actually two). The carts won’t be 36v anymore, but 48v. We are looking to mount a complete solar power plant, with panels, charge controller, inverter, batteries, and the wiring to offer power to appliances. The carts are getting the Chinese Curtis equivalent of the 500 amp 48v pwm controllers. For batteries, I am going with the Remy 8A31DTM or 8A31 (dual or single terminal mount) 105 ah AGM sealed lead acid 12v. I can fit four presently, but I think I want 8.
Today we welded a mount for six Newpowa 100watt panels that will fit on top of the cart. We made the mount out of four 8’ pipeline hose reels.

10 Likes


We still have to figure out some sort of all weather electrical box to hold the charge controller and inverter. We have an Outback 80amp mppt which is huge, so the box is going to have to be pretty big. If we go with the Aims 48v inverter, then it will be huge.

7 Likes

Right now we use the Husqvarna E316 or the Husqvarna 420EL on pwm inverters. We have a Jupiter from Harbor Freight, and a Peak from Amazon. These are our 12v wood cutting inverters, and we will prolly have to rewire the batteries on the cart, 48v to move and 12v for power. At least until we get a 48v inverter.
The outback will configure to both voltages so we wouldn’t have to rewire the panels each time.
So I suppose if anyone has a 48v inverter recommendation, we would appreciate it.

It’s crazy but Google tracks my phone location, and in one month I walk 50 miles back and forth from the camp to the shop. When my knee gets sore I intend on finishing the day driving a cart back and forth from the camp to the sawmill and shop.

9 Likes

I have been thinking about this inverter for an EV tractor I want to build

The power rating and price seems reasonable to me. But I am only in the planing stage at the moment.
This is a very cool project that I will definitely be following.

4 Likes

Interesting project! I have several question. My mind is busy with the same things.

Curtis pwm controller? Are you retrofitting the car?

Solarpanels work best with mppt. Clear. But why use 100 W panels? The bigger panels are more common and therefore cheaper? And they fit almost exact on an EV or trailer (we have three left over for the same porpuse, at the end of the roof there were still three panels).

And why not go with prismatic LiFePo4? Super safe , last forever and very strong. Around 135 dollar/ kWh. For me the way if I build something new.

And for the powertools any inverter will do. No grid connection, so no extra options required.

And where do you put your gasifier for filling up your batt pack?

Nice project!

3 Likes

Dan…I ordered the 48v inverter. I had to message the company because they don’t make it clear that the shipping is free.
We had a similar Magnum inverter in the past. Same features. It quit and Magnum wants $900 plus shipping to just take a look at it. So $659 delivered is worth a roll of the dice.
A few comments about my experience with inverters…
A. Don’t get attached to any of them. They all die.
B. PWM is ok for motors even when the motors get hot.
C. Full sine wave is GOOD for computer switching power supplies.
D. Internal transfer switching is a fantastic feature. Put a LED battery volt meter where you can see it, next to the generator remote start switch…and you can operate for long hours without interruption.
E. Big surge is what makes a little inverter the most efficient. Many appliances have a huge surge when starting but have low draw when operating. An inverter works best at or near it’s maximum power rating. So if you have an inverter matched to the operating load it needs a big surge capacity to handle startups. The other way is to have a low surge big capacity inverter loafing along inefficiently giving a fraction of it’s rating, waiting for a big startup draw. The Magnum 2812 was like that…50watt draw just for being turned on. I have a 600w Peak with a 1/4w draw at idle.

4 Likes

Actually, yes. There are two carts. An EZ-Go and a Melex. Both ran on 36volts DC. The Melex is a Polish cart made in 1952. It has resistors for speed control… very inefficient.
The EZ-GO has a Curtis motor controller, that appears to be pulse width modulated (PWM)


We determined that the Curtis controller had failed. I found a Chinese replacement 500 amp @ 48volts DC for $150.
We also determined that both carts have similar motor wiring. We tested them with 48v direct, and the motors did fine (we had fun too).
We are going to take a leap here and assume the Chinese controller will work on both carts.
What we don’t know is if it comes preprogrammed from the factory. Curtis controllers had to be programmed in the field.

2 Likes

I went through some real agony here. I wanted Kyrocera 350w 24v panels…
I got Newpowa 100w panels for $69 per panel delivered! Delivered!!! Kyrocera was a freight shipment that had to go to a business with a loading dock and a fork lift.

2 Likes

Here again was some serious agony…I want to follow Dan’s and your advice and go with the lipo. I am afraid though. The Remy battery guy lives in my village. He knows he has to sell me batteries at cost. He also knows I won’t tolerate any lying…he has to know what he is selling me. He is the store manager now, and we both went through three store managers, before arriving at this point in time. A previous manager lost his job because he lied to me about the origin of Full River gel batteries.
I find these gel batteries to be long lived. I have 4 C&D Technologies 12-75s that are cell tower take outs from 2008…still working great.
I know as a power supply battery these gel batts will perform for years. I don’t know anything about lipo. I want to learn. I want to be shown. I don’t want to spend my experimentation budget on batteries, I want to spend it on castable refractory for a plastic-to-gasoline fuel making bench.
So lipo is not out, just not yet.

6 Likes

Joep! This is the best question yet!!! I am under great pressure to build a gas producer (gasifier). My sons see the remnants of them all over the place. A dead tractor here, a tipped over hopper rotting over here…Those boys want to see this technology in action! The youngest son wants to make charcoal. It is a perfect storm…the new saw mill producing slabs and pieces, the electric firewood saws producing barrels and barrels of charcoal grade chunks, a willing work force, and this forum.
The answer is that the cart will pull a trailer with gasifier/generator combo pack on board. I am thinking mini buzz-rig for chunk making too.
I suspect there will be working gas producers all over here again.

4 Likes

Well definitely let me know how that inverter works out. I will probably start without it. I am headed down the road of salvaging lithium ion batteries and building my own batteries as you know. So it will be spring again before I am in the market to buy an inverter. Too many pressing farm issues now.
I can’t argue against buying AMG if the price is right and it has the capacity you need in a weight you can live with. I do think Lifepo4 will have a lower risk and lower cost of ownership over time new is just out of my budget right now.

2 Likes

We pay less then that for a complete system, roofmount inverter etc (1 eurocent less). It can’t be that different on your side of the pond. Trina panels we are talking then, China, but everything comes from China nowadays. I just was curious. Here is a big project on a former watercleaning area, maybe a few hectare/acres, and they mound small panels?! Some Spanish people installing it??? Twice as much work then the normal 300/400 W panels??? I thought it must be in the price??

Newpowa is from Canada? Good, support your locals. Few European solar factories left, if there are any.

2 Likes

For me too, learned a lot last year and still lots to learn. Lion is out after one cell exploded for a reason we still don’t know. I was already sleeping, the middle sun (who build the pack) was watching TV, a big bang, I woke up angry because I thought someone was smashing doors, the youngest was in panic, smoke everywhere, fire alarms on every floor, by the time I got out of bed the pack was outside. End of Lion for us. He build a new pack from batt hookup 28-650 LiFePo4. Let’s see what that brings.

Range is super, topspeed he doesn’t want to tell. We all know what that means… testride by papa.

And we ordered a diy 90 Ah prismatic pack for his little fishing boat. I don’t want to have him tow the lead acid around. Big trouble with the chief.

But you are right, if you buy it closely you want get ripped.

3 Likes

Would be nice! I hope too start some day. We have a small land plot we can start from scratch, that means no grid. After that some more into the house/shop. Charcoal is the path for me, and maybe still to difficult :innocent:

1 Like

How many volts is it? 36v is usually about 25 MPH give or take for example.

1 Like

Yep! I feel like a relic, but I better run what I know for now

4 Likes

It is 48 V and last time over 40 mph/ 72 km/h, a little to fast

2 Likes

Me too, but electric surprises me. As long as every wire is connected it functions.

2 Likes

If the pack gets out of ballance one cell will over voltage and can burst into flames. You definitely need a BMS with lithium batteries. Lifepo4 won’t bust into flames they will outgas nasty smoke when abused but more likely you will over discharge them and cause them to fail they really dont like being under voltage from what I have read. My plan is to build the lithium ion into surplus 50 cal ammo cases the metal case will contain any fire should the BMS fail. I would use Lifepo4 if I could afford it much better technology but the cost is higher than salvaged cells and my project just wouldn’t happen at those costs.
With lithium ion you also need individual cell fusing. It is now available from battery hookup as part of the nickel strip. That was a game changer for me. I have looked into it in the past and didn’t want to do it without known fuses. The pick the right length of wire method didn’t sit well with me.

2 Likes

And I’d think the heavier AGM’s would give you better low down anti-tip over ballast weight.
Putting up a large flat plane “sail” on-board, gotta’ start think about sail boat dynamics.
That Wind. She sure can blow at times.
S.U.

4 Likes