Electric Badger 450 Mini Bike

[Functional Artist]

I ordered (4) 12V 12AH "Mighty Max" (SLA) batteries (~$95.00 delivered)
https://www.ebay.com/itm/Mighty-Max...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

While waiting, I figured, I'll work on the seat

The top is cut
...but, the sides are in pretty good shape (except for a little paint on one side)

So, I'll try to sew in a good piece

First, I removed the staples & peeled the cover off

Next, I carefully cut the stitches that connect the top panel to the side

Then, I used the old top panel as a template to draw the dimensions onto the new piece. (black "pin hole" vinyl)
…& finally, cut 'er out kinda closely

 

[Functional Artist]

Got out the sewing machine
...aligned the top panel with the side
…& followed the "old" stich line.

Seemed to come out pretty good

Then, I stretched 'er over the seat cushion/base
...got 'er aligned
...& stapled 'er down

Not exactly perfect
...but, way better

 

[Functional Artist]

Wiring

First we'll start with the easiest connection, the throttle.

It has a (3) wire plug & the speed controller has a corresponding (3) wire plug marked "throttle"
...just gotta be sure that the wires correspond (red to red, black to black & other to other - in this situation green to blue)

Next, is the (2) wire key (on/off) switch. It has a corresponding (2) wire plug is marked "lock".
(wire order doesn't matter, as it just makes or brakes the connection/circuit)

The brake lever has a (2) wire plug that connects to the plug marked "brake"
(wire order doesn't matter on this one either)

There is a another plug marked "brake light", that is to connect to the brake light, it self (if used)
(this one must be connected properly as one wire is positive (+) & the other is negative (-)

The speed controller has a plug marked "charge" where the charge port can be connected
(I usually just connect my charge ports directly to the battery/cables)

Now, lets move on to the circuit breaker.
It has one side marked BATT (line), this is where the positive (+) battery cable is to be connected
(& the positive wire of the charge port too)

The other side is marked AUX (load), this is where the battery cable connects to the positive (+) side of the speed controllers "batt" plug (it sends the current to the speed controller)

 

[Functional Artist]

Battery Cables

Almost forgot, I wanted to go over some info on the battery cables

* Different types, diameters & lengths of wires (& even different terminals/connectors) have different resistances
...which affects the current flowing thru 'em.

So, In an effort to maintain the same/consistant resistances, I am gonna make all (4) cables from the same material (10g. copper wire)
...& of the same length. (~6" ea.)

I will use (3) of them to connect the (4) batteries in series
…& the (4th) will connect the battery pack positive (+) to the Batt (load) side of the circuit breaker

The (3) battery "connector" cables will need spade connectors on both ends. (to connect to the battery terminals)

The (4th) cable will have a spade connector on one end. (to connect to the battery terminal)
...& a 1/4" ring terminal on the other end (to connect to the CB)


Remove ~3/16" of insulation
…(don't forget to) slide a piece of shrink wrap on
...then, insert the wire into the terminal
...crimp firmly (twice if possible)
...slide the shrink wrap into place & apply heat, to shrink

Boom, we have (4) (equally resistant) battery cables

 

[landuse]

Awesome info once again FA!

 

[Functional Artist]

I got our "power pack" from Mighty Max
...(4) 12V 12AH SLA batteries

I cut & installed a rubber pad in the battery box to give 'em a little padding
…& strapped 'em down with some extra HD wire ties

I measured around the battery & tray (~16") & found some 18" HD cable ties (they seemed perfect)
...NOT, just a hare too short

So, then I got some 36" 'er's
...strong, light weight & nice-n-secure
(the first battery will be secured/held in place by the plastic battery box/cover)

Yup. that'll work

 

[Functional Artist]

Finishing 'er up

So, to finish 'er up, I ran a piece of black 10g. from the last (4th) battery thru the "control box", down to the speed controller & also a piece of black 16g. wire to complete the charge port circuit

Then, I soldered the (2) black wires together to the speed controllers negative (-) input
…& coverer 'em in shrink wrap

Tidied up the wires in the "control box"
...put some protective covering over 'em
…& then, closed 'er up

Time for a test ride.

https://www.youtube.com/watch?v=0aX...0vqgrvde5whne5xjrk0h00410&feature=em-comments

 

[JTSpeedDemon]

That's lookin' pretty SWEET! You always do really clean, thorough builds Kevin.

 

[Functional Artist]

I used a GPS to gather some speed data

It looks like with this 48V 1,000W motor, running @ a 7.5:1 gear ratio
...the top speed is ~18MPH

Not super fast
...but, she's a torque monster

So, it seems like there is plenty of power to raise/increase the gear ratio (to like 6:1 or maybe even try going down to 5.4:1)
...thus increasing our top speed

Here is a video of the test ride
(the quality sucks but, it's for gathering data not entertainment purposes)

https://www.youtube.com/watch?v=TNjlG--hKFc

 

[Functional Artist]

Reducing the gear ratio down to 6:1

The bike zips right along @ 7.5:1 (~18 MPH)
(10 tooth "drive" sprocket on the motor & a 75 tooth "driven" sprocket on the axle)
...but, it seems like it's geared too low

It takes a minute to "wind up", while coming up to speed
...then, when riding @ "top speed", the motor seems to be "racing" compared to the "actual" speed that your going
…& then when the throttle is released, it decelerates or "winds down" a lot
(it doesn't really seem "to coast")

So, I'm thinkin' we'll try-n-drop 'er down to ~6:1

I found a 60 tooth sprocket (~$12.95) at BMI Karts
https://www.bmikarts.com/Sprocket-35-60T-No-Bolt-Holes_p_1401.html

Then, lookin' further, I found one just like it for (~9.95)
https://www.bmikarts.com/Sprocket-35-60T-No-Bolt-Holes_p_11973.html

It just has some surface rust on it
...but, I'm gonna clean 'er up & paint 'er anyways

Wow, quite a difference in the price
…& in the size too

But, (luckily) the center holes were pretty dang close in size
...so, I rounded up an appropriate diameter "pin" to align the (2) sprockets
(I just used an old socket with a couple wraps of vinyl tape)

Then, I stacked 'em & clamped 'em together
...to use the "original" sprocket, as a template, to mark where the bolt holes needed to be.

 

[Functional Artist]

Finished drillin' it out
…& then, a little bit of sandin' to smooth 'er off & clean 'er up

Next, a quick "test fit" (just to be sure)

Yup, fits nice-n-snug on the center hub
...& all (6) bolts even threaded in "easily" by hand

Finally, a little primer & then, some gold paint

Big difference this thing should "rock"

 

[Functional Artist]

Reinstalled the rear wheel
….& shortened the chain a bit

It was well after dark & raining when I got 'er done
...so, I just did a quick "up on blocks/let's see what she can do test"
…& attached the RPM meter (just to see)

https://www.youtube.com/watch?v=J6nNT1aSDjw


Well, when operating @ 7.5:1 (@53V) the meter showed ~470 RPM's @ the axle
…& the motors top speed calculated out to be ~3,520 RPM's

But, when operating @ 6:1 (@53V) the meter showed ~620 RPM's @ the axle
…& the motors top speed "now" calculates out to be ~3,720 RPM's

* Was this lower (7.5:1) gear ratio "robbing" this little motor of ~200 RPM's?

 

[Functional Artist]

I got to take 'er for a ride today

Yup, just as we expected
...not quite as torquey
…& a little bit quicker

The top speed for this mini bike
...with a 48V 1,000W motor
...& running @ a 6:1 gear ratio, seems to be ~21 MPH

https://www.youtube.com/watch?v=5bpodZnH5-A

 

[Functional Artist]

I found the 2010 Northern Tools catalog, that I bought my Serengetti Electric Badger 450 (El Mini) out of.

Ad says, "speeds up to 15MPH" (a bit exaggerated)
...but, maybe with 80 lb. rider)

& "up to 1 hour run time" (a lot exaggerated)
...maybe if only going down hill

 

[Kartorbust]

Man it's been that many years since NTE has sold mini bikes and go karts? Gotta love how they inflate numbers like that lol, sounds a bit familiar.

 

[ezreub]

Hey Functional Artist,
I really like this upgrade, and my sons think they want to make our mini-bikes electric instead of gas. We're just wondering how big the sprocket is and also how fast the 48v/1000w set up gets this going.

Thanks a lot and nice work here.

 

[Functional Artist]

Hey Functional Artist,
I really like this upgrade, and my sons think they want to make our mini-bikes electric instead of gas. We're just wondering how big the sprocket is and also how fast the 48v/1000w set up gets this going.

Thanks a lot and nice work here.

Kool! She'll go ~21 MPH with a 6:1 gear ratio

10 tooth drive sprocket on the motor
…& a 60 tooth driven sprocket on the rear wheel

 

[ezreub]

Pretty fast. That should do the trick.

Thanks for the details!

 

[Quinc]

Look at all that room for motor upgrades! What about 2x1000w motors?

 

[Bmr4Karts]

Look at all that room for motor upgrades! What about 2x1000w motors?

One 48v brushless motor will have this going 30mph.