Lithium Conversion (leaf battery)

[rottie]

well, it looks like i am doing a ac conversion system on this Yamaha cart. If customer agrees.
not to just do a little more research. Have been talking with plum quick racing motors. very helpful.i

[bronsonj]

Wow, they are really going all out on that cart! Going AC and lithium. What are they wanting from that cart? I'm wondering if they're talking about more than they can use??? If it's a florida-only cart then a 14S lithium pack should do all they need. If they want max range you can probably fit a 6P, 8P, 10P or larger pack in that cart.

But on the other hand, if they "just want it" then the customer is always right! LOL

Another question, I see your signature indicating you have a solar module on your cart. Do you think that the 150 watt panel makes any difference for your range? Also what charge controller did you use?

[Volt_Ampere]

We had a guy here in Rio Verde that was making Solar carts with a panel like that on the roof. Doesn't work for me - with Lithium I charge when it needs it - not continuously. If you are playing golf, the cart sits a lot so the panels constant small power input will help with range. If you are just driving continuously, it isn't going to do much. I store my cart in my garage so the solar panels would not see sunlight except when I'm out and about.

For me with two Lithium carts, I don't want Solar. They are ok for FLA carts.

[bronsonj]

I've seen the solar question many times so I figured I'd ask. The numbers don't seem to work. 150 watts optimum, likely 115 watts real world with a new panel in full sun, maybe 95 watts to the battery after the charge controller and cables and whatnot. Then if the sun is off angle or partly cloudy then maybe half that?

So I have been thus far telling people that a single panel isn't going to do anything but I still ask when I see people with the panel to see their real-world experience. Just to see if I'm missing anything or if it's better than my assumptions.

[Volt_Ampere]

I don't see the solar panel doing anything terribly useful for a golf cart battery. Maybe if you leave it out all day long it might give you a significant charge but with FLA batteries, you should do a full charge every time you drive it any significant distance. With Lithium, you should try to wait to charge until it's down to 20% or so. Trickle charging isn't terribly good for Lithium. 150 Watts isn't more than 3 amps at 48V - you're lucky if the panel is putting out 2 amps of charge current. My cart pulls 70 amps running at 20mph.

[rottie]

in my opinion; solar is not worth it. not enough watts to make a significate difference.

Customer is going for the AC system.

This will be the Navitas 5kw AC motor at 72V. I have been working with Matt at Plum motor racing. Big help to clarify my issues.
This is one of those limo carts (8 passenger), so it is big and long, like twice the length of a normal cart.
We are going to limit speed to 25MPH or less. (safety and street legal)
I am looking at series up 9 x 3 modules Leaf models for 18S6P.
The goal /requirement is long distance with excellent acceleration.
Top speed is not a concern, just getting up and running in a drag race to <25mph. :)
Yes, there is a big battery compartment, so batteries will easily fit.
Also the customer wants to make this beast street legal, so lights, turn signals, brake lights, wind shield wiper, speedometer, etc.
Also going with larger tire/rim and lift kit. So a lot of work.

Note to all: I will be using copper bus bar (0.125" x 1") to parallel the leaf modules to handle the current. Wires will be 00awg, for minimum resistance.

[bronsonj]

Side note, I thought that FL dropped the windshield wiper requirement. I could be wrong, but I was speaking with a guy with a street legal cart the other day and his didn't have the wiper. He said that was dropped from the reqs.

Sounds like that's going to be one heck of a cool limo.

[rottie]

I think this will be a good project. He is excited about the conversion.
I am also taking lots of pix for the build process.