How do I speed up my electric golf cart?

[MikeFairbanks]

Now that I've had a little over a year building electric bikes and have a better understanding of how they work, I am interested in speeding up my electric golf cart.

Currently it has six 8-volt batteries (I'll have to check for more specifics when I get home). 48 volts is pretty darn good.

I also need to learn about the controller to see if I can make it do more than it is. I just need a little more speed.

Right now it's capable of going about 22mph and I'd like to bring that up a few notches.

It also has (as a safety measure) regenerative braking. I don't want to disable that (my wife would not like that), but I also don't want it to engage too soon.

The batteries are lead acid, of course, but not sealed. I have to occasionally add distilled water.

It's a 2004 Club Car Villager (four-seater).

Thanks

 

[TylerDurden]

Well... overvolt it, of course.

That said, if you open up the controller and show us the goodies, we can give you a better idea how much of a good thing you can take before it runs into money.

 

[MikeFairbanks]

Well, it never occurred to me to modify it electrically. I'll have to see what's inside.

Would adding another battery actually work, or would the controller tell me to buzz off?

I know it has IR (whatever that means). It's some kind of intelligence system to adjust power. I think mine is at the highest setting, but I don't know for sure.

 

[amberwolf]

Many golf carts use Curtis controllers. many, maybe most of them are designed for 24-48V operation, some might be capable of higher voltages. If your cart only uses something less than the max, then you could easily just add another battery in series. Probably regen and drive would work fine that way.

Since the new ones would be different age than the others, you wouldn't want to charge it in series with them, and would instead want to get a separate 6V or 12V or 24V or whatever charger for the new battery(ies). Also, if you did charge it in series with them the higher voltage charger would probably be more expensive than the smaller one to charge just the new ones. If your new charger is isolated output, then there is no problem just connecting it to the new ones while you are also charging the old ones with the original charger. If it is not isolated, you must unplug the original charger first.


If the controller isnt' already spec'd for the higher voltage, then I'd recommend checking inside it to see if it's FETs and caps are capable of it, and that the low voltage controller section inside it (a separate PCB to teh side of the power PCB in a typical Curtis) can handle that higher voltage. If not, you'd need tod o some modifications, or replace the controller with a higher voltage version.
Some people on DIY Electric Car forums have upgraded their Curtis brushed controllers like this.

If the motor uses a chain drive to run the wheels, then you could also change the sprocket size at either end, but this will affect your takeoff speed and power usage as well, possibly increasing the startup current beyond what the controller can safely handle if you go too extreme with the ratio change.


Keep in mind that you'd be wearing the brushes in teh motor faster at teh higher voltage and current, and it will heat the motor more, so you may wish to monitor it's internal temperature both before and after the upgrade, to see if it is going to be problematic.