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8 Seater Buggy Conversion

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Enemzack:
Hi Guys,

I purchased a custom made 48v 15kw bldc air cooling motor with vec600 controller (rated at 250A, max 600A).

The estimate weight approximately 1300kg.

On a normal flat road, the 8 seater buggy works perfectly on a full load.

Problem:
On a slope, it failed to climb.

the setting that golden ask to change is to change the battery drawn current limit to 235.

any ideas for improvement? or the motor power is not enough?


Nik

Bikemad:
Hi Nik,

Unfortunately, I think the power is simply too low for that amount of weight.

Just as an example, my Vectrix electric scooter weighs 210kg, but the 120V pack allows the 7kW continuous motor to deliver over 20kW peak (27HP).
And the five seater Nissan leaf weighs ~1,500kg and uses a 80kW motor and a 365V battery pack. :o

Even with your battery drawn current set to 235A, that's only going to provide just over 10kW of usable power output at the wheels with a 48V pack (after electrical and mechanical inefficiency losses).

If you cannot increase the power, the only alternative I can see would be to lower the gearing sufficiently so that steep hills could be climbed with just 10kW of power (albeit at a very slow speed).  :-[

Alan
 

StadsImker:
I think the problem is that you need to realize is that an engine should rotate to generate power and it even doesn't matter what kind of engine or motor you use. Benzine, electric or what ever.

If it isn't rotating, there is no power or torque at all. It's simply stalled. If you try to force it.... it will damage it self somewhere. In a combustion engine it will burn you clutch or stops running. In an electrical engine... It will send a high current and... "notting happens" but a lot happens, but we don't hear it. But it screams HELP... On a electric bike you need to pedale to start on a hill... With a buggy you need to "create better conditions". Stop trying hills with no speed. Take a longer run and than go up the hill.

Bikemad:

--- Quote from: StadsImker on February 08, 2017, 02:59:54 PM ---If it isn't rotating, there is no power or torque at all.
--- End quote ---

Actually, plenty of torque is available at zero rpm with an electric motor.

I once carried out a very simple stall test using a set of digital luggage scales attached by a piece of rope tied to the outer diameter of my tyre as shown here:



My modified Pie was drawing 65.94 Amps @ 25.6V (1,694 Watts) and although the controller cut the power before the luggage scales had time to lock the reading, I was able to read a reading of at least 28kgs/61Lbs of force on a couple of the tests, which I worked out to be around 93Nm of torque!

For a vehicle to pull away on a slope from a standing start, the stall torque needs to be greater than the torque required to drive the vehicle up the slope. If this minimum required amount of torque is not available, then it will not pull away.

Alan
 

Enemzack:
Hi Alan,

If I can upgrade the motor, would the highest available motor golden motor have sufficient?

20kw 96v system.

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