Solar powered motor

[xandervdm]

Beau above has given you some excellent advice based on real life experience. A 250w motor isn't very powerful so be careful with your aerodynamics and weight or consider using two motors - they will take a current/power proportional to the load put on them so running two motors at a vehicle speed of 8mph will not be that much more power consumption than running one of them.

Maybe try it with one, keep the fact that you might need a second motor in the back of your mind and design your kart with the option of a second motor.

I work in the automotive industry and we've seen some interesting stuff through our doors including a design by one of the world leading designers in motor technology - fascinating bloke.

A 250w 24v motor run from 2 x 12AH 12V batteries will run for approximately an hour but pick your batteries carefully as a lot of the lead acid batteries don't like being discharged too much.

If your course is nice and flat, your weight isn't as much of a hindrance as if you have lots of slopes. Once you get up to speed, your only major power drains are your rolling resistance and air resistance. If your course is not flat, consider using some kind of energy recovery system in your controller design.

Good luck

Hi, you say that it can run for approx 1 hour but do you think it's possible that a solar panel powers the motor while driving so it has a much longer range?

 

[picbits]

Hi, you say that it can run for approx 1 hour but do you think it's possible that a solar panel powers the motor while driving so it has a much longer range?

It was an example - you'll have to do the calculations yourself for your project.

I'm sure part of the marking criteria is how you've come to decisions and conclusions and to prove that, you should do your own research and understand the calculations .

 

[xandervdm]

I made some calculations, can you check if they are correct?

Battery runtime:

Motor uses: 13,5 Amps
Battery has: 5 Ah

Total runtime = 5/13,5 = 0,37 Hour = 22 minutes

Battery charge time:

Solar panel produces: 500watt/24volt = 21 Amps
Battery has: 5 Ah

Total charge time = 5/21 =0,24 Hour = 14 Minutes (with maximum solar power)

It was an example - you'll have to do the calculations yourself for your project.

I'm sure part of the marking criteria is how you've come to decisions and conclusions and to prove that, you should do your own research and understand the calculations .

 

[Pommie]

If your panel is producing 300W then it will run your motor and charge the battery a little. When accelerating the battery will also provide power and will get charged more on coasting.

Mike.

 

[xandervdm]

If your panel is producing 300W then it will run your motor and charge the battery a little. When accelerating the battery will also provide power and will get charged more on coasting.

Mike.

Yes but the panel only produces 300w in maximum sun power

 

[Pommie]

Yes but the panel only produces 300w in maximum sun power

Then why are you using 500W in your above calculations?

Mike.

 

[xandervdm]

Then why are you using 500W in your above calculations?

Mike.

because there never is maximum sun power

 

[Pommie]

You stated above,

Solar panel produces: 500watt

So I used 300W as a conservative estimate.

Mike.

 

[Tony Stewart]

keep in mind starting max torque may draw up to 10x max rated power and for max power, losses must be minimized in every component and cable. Also RPM drops to about 82% if full load matches motor rating