[Kiwimike]

Hi folks,

I´ve wanted to do an EV for a very long time. I now live in Brazil where it is extremely difficult to find something like an old forklift motor and controller, and to find an affordable one even harder - $10k Brazilian when i looked the other day online (to put that in perspective the minimum wage here is $1k Brazilian a month).

But a stroke of luck may have handed me the opportunity to get started. Long story short, a guy locally has the whole components and wiring harness of a 2011-ish clubcar of some sort. It also has the 48v 'power drive' charger.

Here are the main specs:
FSIP (flight systems industrial products)
Series Motor Controller 51-42L500NNVS (48v 500 amps)

Series wound GE motor model 5BC49JB1134
48V,
11.4HP
2280RMP, 228 Amps

All i want to do is convert a VW Beetle on the cheap and get 60 km/h (37MPH), just for running around town. Over time i'll get into recycled Lithium laptop batteries.

So on the surface it looks good right?? I've seen guys get reasonable results with much less and theres a guy on here who put a club car system in his car with good results although it was an older system.

The fundamental question i have is when i go to the club car website, these models have a max speed of only 18 mph (29 km/h). Thats my concern with this setup. Why are these things so slow?! Will taller wheels and a gear box let me get to 60 km/h (37MPH)???

Obviously the battery pack will have to be upgraded. 6 x 8v batteries isn't going to get me far!!

What do you guys think? Any feed back will be appreciated.

Cheers, Mike

 

[Scotty274]

Hey mate, so with 3,700RPM and 8hp, that motor would struggle to get a beetle moving, let alone at speed.

 

[cricketo]

There are several reasons Golf Carts are that slow, one being the fact they're just not built with the stability and handling necessary for higher speeds. One of the tricks people with Buggies use is to swap out for the higher voltage battery / controller (if necessary). Motors typically handle some degree of voltage increase without consequences, so if you're willing to take a risk you may be able to squeeze out a bit more juice out of it. Then the other thing is overall RPM rating of the motor. Pushing it beyond certain point mechanically even if it can handle it electrically may destroy it

Here is a good resource for you with lots of similar questions discussed and answered : Extreme Electric Golf Carts

 

[Kiwimike]

Hey mate, so with 3,700RPM and 8hp, that motor would struggle to get a beetle moving, let alone at speed.

Cheers Scotty. Based on what others have run it doesn't actually take that much to get a small car moving. The example cited above used a 3.5 HP in a beetle which would get 60km/h at 60v fully charged. Obviously there are major issues with pushing a little motor hard like that and the faster you go the larger the capacity of the system will need to be.

 

[Kiwimike]

There are several reasons Golf Carts are that slow, one being the fact they're just not built with the stability and handling necessary for higher speeds. One of the tricks people with Buggies use is to swap out for the higher voltage battery / controller (if necessary). Motors typically handle some degree of voltage increase without consequences, so if you're willing to take a risk you may be able to squeeze out a bit more juice out of it. Then the other thing is overall RPM rating of the motor. Pushing it beyond certain point mechanically even if it can handle it electrically may destroy it

Here is a good resource for you with lots of similar questions discussed and answered : Extreme Electric Golf Carts

Cheers for the link Cricketo. Yeah i figured fully charged @ 60v will be fine for 60km/h, and thats technically doable within its max rpm of ~2300rpm. Now that i've seen the motor in person, its only a 6inch i think and most worryingly is the time rating of 5min. Couldn't find its spec sheet but i figure it would be drawing towards its amp limits to maintain 60km/h, but only trying it to find out eh?! So i'd already need to put a blower on it no doubt. Thing is, big dc motors are rare as hens teeth over here. Electric forklifts are only used when obligatory and are always the small ones with 24v and 36v motors/controllers. Just to complicate things, the motor doesnt have a drive end 'face plate' on it.... just another hurdle. I'm learning though...

 

[cricketo]

Electric forklifts are only used when obligatory and are always the small ones with 24v and 36v motors/controllers. Just to complicate things, the motor doesnt have a drive end 'face plate' on it....

I have a 36v forklift, and the motor is labeled 36/48v. Sometimes you may be pleasantly surprised

 

[Kiwimike]

I have a 36v forklift, and the motor is labeled 36/48v. Sometimes you may be pleasantly surprised

Now that is a nice surprise!!! I'll have to check your project...

 

[MattsAwesomeStuff]

The controller is good for 32hp. That's your hard limit without spending a bunch of money.

Luckily, I think 32hp is lots to push a Beetle 60km/h. Lots and lots, even uphill.

The motor is probably your weakpoint. It will be pushed hard. But even then, I think with aggressive cooling you will be okay.

To maintain 60km/h in a 1000kg vehicle on flat terrain only takes 5.5hp. Roughly double that is nice to have moderate acceleration. So 11hp. And it's an 11hp motor.

To go uphill moderately steep (though not Brazil-steep), will require 28hp to go up a 10 degree slope. So, your controller can handle full speed uphill, but the motor is not going to like it.

I think you have modest and achieveable goals, and I think your powerplant and controller will be appropriate for the application.

 

[Kiwimike]

The controller is good for 32hp. That's your hard limit without spending a bunch of money.

Luckily, I think 32hp is lots to push a Beetle 60km/h. Lots and lots, even uphill.

The motor is probably your weakpoint. It will be pushed hard. But even then, I think with aggressive cooling you will be okay.

To maintain 60km/h in a 1000kg vehicle on flat terrain only takes 5.5hp. Roughly double that is nice to have moderate acceleration. So 11hp. And it's an 11hp motor.

To go uphill moderately steep (though not Brazil-steep), will require 28hp to go up a 10 degree slope. So, your controller can handle full speed uphill, but the motor is not going to like it.

I think you have modest and achieveable goals, and I think your powerplant and controller will be appropriate for the application.

Cheers Matt, thats a great help. After a bit of research i had drawn similar conclusions, particularly that the motor is the weak link. I have several questions specific to the motor but i'll save that for the motor section. Thankfully my region doesn't really have any hills and getting to the city center is only 10-15 minutes away, which would be the ultimate goal.