Xtreme XB-600 (electric scooter mods)

[captainslug]

I was looking at the 48V 1KW Regenerative Braking motor controller than Golden Motor offers.

But they won't answer any questions about whether or not it could handle 60 volts. The stock controller for this scooter has motor braking, but it doesn't utilize the current to recharge the batteries.
Golden Motor also offers a 48V 1KW hub motor in a 16" cast aluminum rim that could be a direct replacement for my current one.

A 1KW motor and 1KW motor would result in having a 24 MPH top speed on level ground at only 48V instead of 60V. At higher voltages it would probably end up at a non-legal speed.

But, I think I want to continue on the path of having high voltage and low amperage. I think that will net me a much higher total range, and I'll have the performance figures I'll be happier with (29mph on level ground, 25MPH uphill, 35-40 miles range).

When I do go to 72V I'll probably mount the charger(s) on the scooter.

[captainslug]

Made a replacement platform/battery cover.

I'm going to be consolidating the batteries, wiring, and controller into the floor of the frame.

Which will leave the area under the seat really empty. At a later date I might make a cargo box for under the seat.

And I cut a mounting hole in the seat frame for the charger receptacle.

[bennelson]

Originally Posted by captainslug

But, I think I want to continue on the path of having high voltage and low amperage.

That sounds like a good idea. Will all the electric car guys I talk to, High Voltage/Low Amps is the big concept I hear over and over.

My first EV was a mountain bike frame with a Golden Motor front wheel hub motor kit. It worked well, I was happy with it.

That project got me started on my electric motorcycle. The motorcycle has been fine on 48 volts, but I would LOVE 72!!!!

A guess my advice is to go with the highest voltage you can afford!

[captainslug]

Upgrading to 72 volts will involve replacing $40 worth of components in the controller, and buying another battery ($40).
I'll get around to it eventually. It may take me a while to convince myself to desolder and resolder than many connections. (15 x 3 + 8 = 53 pins )

Then I'll have to mount and wire in the 60V charger for the 5-pack and a 12V charger for the 6th battery. 72V chargers are just too expensive, especially considering the small size of these 20ah batteries.

[MazdaMatt]

Just a thought regarding power savings and LED lights. You may get better power consumption AND less tedius crappy soldering/heatshrinking if you used the LEDs in series with a single resistor at the end of the string.

You are using 12V supply, a LED (assume 2V drop) and a resistor. There is a 10V drop across the resistor (510ohm) so you're pushing about 0.02A through the LEDs, that's 0.2W per resistor wasted.

If instead you were to string 5 LEDs in series, you'd have a 10V drop across the LEDs, leaving you with 2V to burn off in a resistor. To get 0.02A across a resistor at 2V you'd need a 100ohm resistor, and you'd be burning off 0.04W per FIVE leds as waste.

If you wanted to do without the 12V headache altogether, you could run 23 LED's in series to the 48V supply... you'd be left with 2V, so you use a 100ohm resistor and you've got 0.04W burned off for 23 LEDs.

Adjust my math based on the actual current usage of the LEDs you are using.

[MazdaMatt]

Oh yeah... if you did the 23 LED string, the intensity would be severely battery-voltage dependant... if you hit 45 volts, the LEDs may not even turn on... but the other idea is still valid.

[captainslug]

Yeah, I understand all of that. I will be wiring the LED running headlight in sets of 4 LEDs with a 180ohm resistor for each set.
One resistor per LED will will end up wasting a good deal of power relative to the LEDs themselves. I didn't realize that when I made the brake light array, so I will be replacing it with two sets of four 14 lumen LEDs.

There's not much voltage drift in the power supplied by the DC-DC converter, so I don't have to make my arrays for as wide of a voltage as I would to power them from a battery.

[captainslug]

The headlight fixture arrived. I got the images for the first few steps of the LED headlight process done. Will post the write-up after the headlight is finished.

I'm not sure when the Luxeon LED will arrive.

[MazdaMatt]

Rather than strings of four, you ought to find out how much voltage drop there is across the LED and use the largest number possible while staying under your source voltage. ie, if they are 2V and you have a 12V supply, use 5, if they are 1.6, use 7 of them. This gives you the best efficiency out of the circuit.

[bennelson]

Captain Slug,

Your LED headlight is cool enough that you could almost make your own thread just about the headlight!

You may also want to put something about it out on Instructables. Everyone LOVES LEDs on there!