THE EXCALIBUR - ELECTRIC CONVERSION PROJECT

[Shailendra Shankar]

Hi guys,

This is SHAILENDRA SHANKAR, from Chennai, India. I have a Bachelor’s degree in Mechanical Engineering and a Master’s degree in Energy and Environmental Engineering. This combination makes me a BeliEVer. After much deliberation and an early mid-life crisis, I have finally started taking steps for my pilot conversion project. Deliberation, because I cleared my 2nd Semester course called BASIC ELECTRICAL ENGINEERING - I and my 3rd Semester course called BASIC ELECTRICAL ENGINEERING - II only in my 5th Semester. So it was going to be tough.

I did a basic study about EVs and found out that the whole thing was rather simple (yeah, right.)

I need 5 things to pull this off.
A donor Bike
Motor
Battery
Throttle
Bucket loads of Cash

I had none of the above. But nothing is going to stop me.

THE DONOR:

It took quite a while to zero in on a donor. I had many bikes in mind. Since I did not have a bike in hand, I had to buy a second-hand one. Which costs money. So I had to ask around if anybody was willing to donate a bike for SCIENCE.

A friend of mine fortunately had a bike, and was willing to give me the bike, for SCIENCE. He originally wanted to bring the baby back to life but gave up on the idea. He said that it had been sleeping in his garage for many years (literally flat on the floor). It had been there for so long that he had forgotten it’s existence.

As you can see, there was really nothing my friend could do with it. It had no papers to prove it was road worthy, so I thought I might as well convert it into an electric bike. It would still be illegal to ride, but who would care.

It is a K(awasaki)Bajaj Caliber. Or at least it was. A 4-stroke, air cooled, single cylinder 111.60cc city commuter.

THE MOTOR:

I had initially planned on a mid-drive motor, but then changed my mind.

I got a little greedy and wanted the entire engine area and if possible the petrol tank for the battery and settled with a HUB MOTOR.

I contacted QS MOTOR (SIAECOSYS - pronounced “psychosis”) for an ideal hub motor and settled with the QS 205 3kW 50H V3 ebike spoke hub motor with 18x1.6 in rim, QSSVMC72150 Controller, with disc brake, three speed throttle and a DC-DC Converter.

THE BATTERY:

Here is where I am absolutely clueless. I asked around for a 72V 100Ah battery with a suitable 5A or above charger and they gave me bewildered looks. Maybe I was asking for too much.

You guys can be the judge here and suggest a suitable battery for this bike.

Could you guys also suggest a suitable material for a housing for the battery pack.

QS Motors tells me the top speed of the hub motor will be about 70-80 kmph @ 72V. Now I am comfortable with that considering a mix of highway and city roads in my office commute.

I want to do 80-100km per full charge @ 40 kmph and a top speed of 80 kmph. Is that too much? I don't know. Do tell me.

THE THROTTLE:

I will be getting a three speed throttle with the hub motor as a part of the kit. So I will not be worrying about it.

THE BUCKET LOADS OF CASH:

Now for the most important prerequisite. I will be talking in my native currency Rupees (₨), so bear with me.

The motor kit costs me Rs. 62,420.22 through PAYPAL. Now for a guy with a family(wife and kids and mom), a Rs. 25,000.00 per month salary and two maxed out credit cards, this is near impossible.
So, I am taking the modern route and I am going to go e-begging, a.k.a CROWDFUNDING.
I have to come up with a heart-wrenching, tear-jerking story to beat all the cancer patients there.
And so I have decided to withdraw Rs. 1,00,000.00 from my savings fund, to cover my immediate costs. And most probably win it back with the crowdfunded money.

I am going to name this vehicle “THE EXCALIBUR”, the legendary sword of King Arthur,because it is an ex-Caliber.

So please let me know what you think about the whole thing, suggestions are welcome, criticisms too.

 

[Dui ni shuo de dui]

Hello Mate,

No offense, but be realistic: don't attempt this if you don't have the budget or if it implies taking a loan/withdrawing your saving funds, especially to build something which wouldn't be street legal in your country.
You'd rather stay budget friendly and go for a scooter instead, not only for money reasons but also because you don't have much electric vehicle building experience either, the first build is always full of mistakes, so it's always wiser to do mistakes on a cheaper setup.

A 100Ah battery would be way too big to fit your frame, I'd say you might be able to squeeze 30, maybe 50Ah if you're lucky, but not much more without heavy frame modifications. And a 72V 50Ah battery is very expensive, also considering the fact that most of them have a relatively low lifespan (depends on which chemistry you choose and how harsh the conditions under which they'll have to work, but they won't last forever anyway, usually 3-4 years for the random no name ones).

It's not an impossible project, but do it when you have money for it, unless you consider it as an investment to show your skills for some kind of long term purpose (getting a better job, promoting your company or whatever).

Oh, and also, I'm not sure if this is what you mean by :
"I have to come up with a heart-wrenching, tear-jerking story to beat all the cancer patients there."
, but please don't scam the nice folks who donate money to help people in need, that would really be awful (I sure hope that's not what you meant, but just in case).