--- 48 volt golf cart motor --- for diy hybrid possible?

[basslover911]

I would love to make a car semi hybrid by adding a small 48 volt 7-13hp golf cart motor and some batteries. Would those motors propel me to at least 15mph?

I just want to add auto start/stop to the engine so the electric can go to 15mph and then the gas take over. I could also add regen braking... ??

If not what good cheap engine would take me to those speeds? (and probaably 48 volts to keep it cheap on the batteries and controllers)

[MetroMPG]

A golf cart motor and 48v would work, yes. Being a smaller motor, it would be more succeptible to heating up, but if you're only using it for intermittent duty, it would probably be OK.

The biggest challenges are:

1) the motor may not have a drive end bearing - many golf carts use the differential to hold the end of the motor shaft in place. So you'd have to fab something up with a bearing in it

2) where would you install it in your car? What would it drive? Options are: 5th gearset; drive shaft (either sprocket onto a FWD axle, or inline or sprocket on a RWD shaft); 5th wheel; chain/belt drive off one of the rear wheels

3) Series DC motors (assuming that's what you're considering) aren't ideally suited for regen. Perm magnet motors (Etek) would be better, but still require either a special controller, or some custom circuitry.

It's not impossible. Mike's Honda Insight 5th wheel is running 48v with an Etek motor, and Coyote X's Metro is running 72v with a small motor as well. (Search for details)

Remember the 2070 lb ForkenSwift is also 48v/400A and can get up to 40+ mph on the level (eventually).

[basslover911]

Thats right I was trying to look for what the forkenswift was using but I never could find it (horsepower that is, since you can have a 1hp 48v and a 50hp 48v).... ?

I was looking again at just the 10hp engines. It will be driving the rear wheels (on a fwd car that is also awd in another trim so all the parts for the back are really easy to get). Another challenge is how many amp hours i would need...

[MetroMPG]

The 10hp rating on that motor... it's really just a guideline.

It's rated for 10hp at a specific duty cycle, eg. "1 hour" or "continuous" before it overheats.

But you can stuff extra juice through it to coax, say, 20 hp from it. But obviously for less time before it heats up too much. And not so much power that you twist the motor shaft off like an apple stem.

OR... you can add forced air cooling to extend the duty cycle, like in Pauls VW Beetle series DC motor or Mike's Insight 5th wheel permanent magnet Etek.

[Ryland]

a golf cart motor would be cheap, but not ideal, no regen-braking, weird female splined shaft without a support bearing, common motors are only 3-5hp, high output motors are 6-8hp, top of the line motors are 10hp.

[basslover911]

Well I can get a high output with regen for $400 (some president golf carts do have regen braking so...)

or what other cheap ideal solution would you see viable to use?

[bluetwo]

I'm really interested now that you mention the AWD setup (in a different trim level).

It makes me wonder if a CRV or Element with Realtime AWD could easily be converted to get a little push from an electric motor.

Now I have to look up the scematics for Honda's Realtime AWD system. Lol....

[Clev]

Originally Posted by bluetwo

I'm really interested now that you mention the AWD setup (in a different trim level).

It makes me wonder if a CRV or Element with Realtime AWD could easily be converted to get a little push from an electric motor.

Now I have to look up the scematics for Honda's Realtime AWD system. Lol....

Honda CR-V Owners FAQ - CarSpace Automotive Forums

The CR-V uses a transfer case at the front which is always engaged and sends power via a propeller shaft to the rear. In front of the rear diff is a pump and clutch pack that decides whether the propeller shaft actually engages the rear diff.

[Christ]

Older Honda Civic WagoVan models with RT4WD had a viscous coupling unit between the rear axle and xfer case. Xfer always driven, but the viscous coupler was disengaged unless the speed differential was X-RPM between the input and ouput of the viscous coupler.

Literally, that coupler can be several thin plates meshed together longitudinally, which work on the boundary layer principle and the thermodynamic principle of heat expansion. They're basically soaked in 10W30 all the time, and as one side begins overspeeding the other side, the viscous fluid heats up, expanding, which increases the boundary layer effect of the oil on the plates, making a viscous bond between input and output until there is no more slippage, at which point, the oil cools down. The system wastes some energy as heat to keep transferring power, so it's not 100% efficient. More like 90%, I think. The efficiency and stall speed (the speed differential at which it begins transferring power due to heat generation) can be affected by the gap between plates, and the thickness of the oil.

This is not the only type of system, but it's a very rudimentary way to explain how the system works.

[bluetwo]

Yep, good explanations. Here's what Wiki has to say about it: Honda CR-V - Wikipedia, the free encyclopedia

I haven't seen what it looks like mechanically, but wouldn't it be a trip if someone could say, Motor/generator1 from a Hybrid Synergy Drive system to make a Honda more efficient. Ha ha ha