Paul & Sabrina's Cheap EV Conversion

[MPaulHolmes]

I'm getting ready to test the controller at 48v with that bank of... I forgot how many... LEDs. I'm guessing about 24 ERRRRR so. That feels familiar.

Also, we bought some copper tubing (about 2 feet). It's inner diameter is just barely big enough to fit the 2 gauge copper cable inside it. I'm going to use it to make some lugs. I'm also making a hex crimper out of some really big bolt cutters from harbor freight. It beats paying like $200 for a hex crimper.

[ttoyoda]

I'm going to use it to make some lugs. I'm also making a hex crimper out of some really big bolt cutters from harbor freight. It beats paying like $200 for a hex crimper.

I found a hex crimper for $6 at Lowes, it was with the bolt cutters and no one knew what it was. I think they may also be sold at harbor.

[offroad1994]

So what is the running grand total cost for the project?

[MPaulHolmes]

I have no idea!! Let's find out...

Potbox: $5 (homemade)
Copper Cable: $50 (most lugs included, ebay)
Motor: $147 (ebay, including shipping)
Controller: $100 (ebay, including shipping)
Lugs: $6 (homemade, using solder and copper pipe)
Adapter Plate & Coupler: $85 (homemade, could have been maybe $65. Steel spacers!)
Car: $40 (bought for $200, sold motor for $160)
48v Charger: $80 (four 12v 6amp smart chargers)
Fuse & Holder: $10 (ebay, including shipping)
All in one Contactor/Emergency Disconnect: $40 (ebay, including shipping)
Controller Heatsink: $20

I haven't gotten these yet:
Battery Boxes: $50 ??
Angle Iron: $20 (bed frame) ??
Battery Tiedowns: $40 ???
Batteries: $76*9 = $684 (Costco, including deposit and taxes)
Misc wire: Free (got it from 2 old vacuum cleaner cords, so it's all black and white!)

Other: $??????

So far the estimated cost is going to be...
$1377

I estimate the range (according to the idea at evolks.com that range is 3 to 5 miles per battery) to be between 24 and 40 miles per charge at around 30 mph on flat ground, in a vacuum.

[offroad1994]

So what is the GVW (Gross vehicle Weight) limit for the vehicle? Are you getting close to it with the batteries and hardware all combined?

Also how do you feel (not saying you should not do the conversion - due to safety - just wondering what you thought about safety as a factor) about the inherent safety decrease by redesign of the drive train with batteries? With all this weight in the storage compartment the batteries (or the box) could become a exploding missile with the wrong kind of crash. Not saying this will happen, but it could; and a motorcycle is no less of a dangerous ride in most circumstances.

[MPaulHolmes]

I'm not worried about flying batteries or box, because they will be bolted and strapped down, and isolated from the passenger compartment. That's a very good question, and fortunately it has been solved by EV designers over the last 30 years or so. Also, the batteries will only weigh about 320 pounds, and the motor is less than 1/2 of the weight of the engine, so it will only be about an extra 150 pounds. I'll just pretend that Oprah's evening meal is riding in the car with me.

Here's an interesting little anecdote:

My wife's car exploded (gas car) while her mom and brother were inside it driving down the freeway. They weren't hurt. The explosion stayed in the engine compartment. I won't have any of that dangerous gasoline in my car. Also, my charger and ghetto controller are so weenie in nature, that there will be very little gassing from the batteries, which is more than I can say for things over at Oprah's house, after a meal of baked beans.

[MPaulHolmes]

I tested the controller, and that little bugger works! I had it wired perfectly on the first try, and you know what? There was a bad LED in my bank which made me think that I had it wired wrong. grrr..... So, I rewired it. Didn't work! Tried the 48v straight across the LEDs and nothing happened! Aha!

I removed a few and booya! I vroomed over and over, making the lights dim and get bright again and again. It was fun!

[offroad1994]

Paul - I saw your ebike in the first posting on this message thread. How much did that cost to make, grand total?

[MPaulHolmes]

At first, the total cost was

Hub motor built into rim: $170
Bike: Free (from the woods)
Batteries: $30 (used on Ebay, still working. I used them for my 48v Car controller test)
ON/OFF switch: $4 (direct drive, no controller)

$204.

Then I added a controller and throttle, and the price skyrocketed to $280!

[offroad1994]

Originally Posted by MPaulHolmes

Hub motor built into rim: $170

So where did you get the hub motor for that price? I think I am going down your same path of experimenting with the smaller stuff first. I can not find any ebay prices for that hub for that cheap. It makes perfect sense what you did about the switch on the bicycle. Just use the motor when you are moving only, and then later get a controller.

Incremental investment is always more interesting as you learn.

In fact I also found a woods-junkyard bicycle that I have running now. Just need a hub motor.