2020 - Excalibur Electric Racing kart

[Functional Artist]

Workin' on, gettin' 'er back together

I must say Dual Motors just look "Bad Azz"

I had ta "borrow" the 60T driven sprocket off of my Damien kart (just for a minute, 'till I get's another)
...& it's even still "sportin' a "killer" reflection

 

[Karts of Kaos]

are the diy gk sticker available for purchase? also looking good!

 

[landuse]

are the diy gk sticker available for purchase? also looking good!

I think RobertD still has some stickers and maybe a T-shirt or two. Send him a PM

 

[Functional Artist]

are the diy gk sticker available for purchase? also looking good!

Thanks!

Yup as far as I know they still are

Check this thread
https://www.diygokarts.com/vb/showthread.php?t=24822

 

[Functional Artist]

I got 'er mostly back together

TBH after the wiring fiasco (I caused) on the Lunar Rover
...I'm not super/100% sure/confidant about this dual motor harness

So, I've been takin' my time & completely re-wiring 'er
...plus, I had ta wait on some 22-4 wire (22g with 4 individually colored/separate conductors)

While waitin' I thought about adding a front bumper
...to help protect the pedals & the drivers feet (like on the karts in the movie)

I notice that they are usually smaller & "lighter duty" than, the frame
...& also, "bolted on"/not welded on

* I would say, probably so their changeable (if/when damaged)

So, I figured I'd try & make a "light duty" front bumper outta a piece of ~1/2" electrical conduit
& just flatten the ends (so, it'll be "easily" mountable to the spindle brackets)

First, I gotta make a "jig"

Measured, marked, drilled a piece of 1/4" x 2" steel
...& then, cut 'er in half

Test:
Slid a piece of conduit ~2" into the "pressing plates"
...& pressed the crap out of it

Well, that seemed to come out pretty good

 

[Functional Artist]

Did some measurin' & markin' (where the (2) bends needed to be)
...& then, cut 'er off

Next, I flattened the other end (before bending)
...to help keep the (2) ends "aligned"

Then, used a conduit bender to add a couple of gentle bends
...& "fitted" 'er up on the kart

A bit of adjustin' on the flattened ends
...& it fit "purty" nicely

 

[Functional Artist]

Re-assembled & Ready to Test

(singing) She's "ready to roll"
...so, "I took 'er for a ride"

Started off with 52.2V in the battery pack
...the (2) SC's were registering as 7.8W & are drawing ~0.15A (when cold)
...& 0Wh (energy used) showing on the meter

Then, after ~40 minutes of hard riding the batt pack was down to 46.5V
...the (2) SC's were now registering as 5.5W & drawing ~0.12A (warmed up)
...& we used/"pulled" 338Wh (of energy) out of them (4) little batteries

Here is a video of "almost" the entire ride

I sat the camera down a few times to "just drive"
...& also, sped up a few parts to reduce "boredom"
...but, still show the data

https://www.youtube.com/watch?v=sOplRpY3Qcs

 

[Functional Artist]

More ridin'/testin'

I've been ridin'
...& testin' the shiz outta this kart

I mounted the GPS, to get some "actual" speed data

I got even got a bit more out of the batt pack this "run"
...the meter showed 'er down to 47V with 345Wh used

After the "test ride" (30+ min.) she was barely "puttin" along
...but, still got me back to the "pitts"

https://www.youtube.com/watch?v=8nx1SOTNF90

 

[Functional Artist]

Upgrade to Lithium

Now its time to try a Lithium battery pack

Here are the specs
YX YH DC

48V 35Ah Ternary lithium Battery Pack (~$375.00)
https://www.ebay.com/itm/48V35Ah-Ter...72.m2749.l2649

Description
ENERGY THE ELECTRIC ADVANTAGE
* Rated Voltage: 48V
* Nominal Voltage : 51.2V
* Capacity (amp hours) : 35Ah
* Continuous Discharge current : 50A

SIZE & WEIGHT ADVANTAGE
* Size (L x W x H): 280*180*85mm/11.1*7.1*3.4inch
* Weight: About 9.35KG/20.6lb

TECHNOLOGY ADVANTAGE
* Usable Capacity (AH): 35AH
* Depth of Discharge : 100% DOD
* Automatic Over Voltage Protection : 58.4V
* Reserve Minutes @ 10A 6 min
* Self Discharge <3% per month

SAFETY & PROTECTION ADVANTAGE
* Built in Automatic Battery Protection System Internal
* Automatic Short Circuit Protection Instant
* Flame Retardant Electrolyte : Yes
* Length Way Circuit Boards : Yes
* Automatic Internal Cell Balancing : Yes
* Explosion Proof Polymer Cells :Yes

Features
* Fully automatic built in battery protection system
* Long life 1000 - 2000 cycles
* Lightweight - up to 70% lighter than lead
* No voltage sag - faster cranking for motors and higher voltage for continuous consistent power.
* Dry Battery - no toxic lead or acid
* Green ROHS compliant - No Lead
* Does not heat up during use

Package List
1 x 48V 35AH Lithium Li-ion Battery Pack
1 x 54.6V 5A Charger
1 x 50A BMS (BMS is built in the battery pack)
2 x Anderson plug(discharge)
1 x Three-hole charging plug
1 x charger Operating instructionn

So, this 48V 35AH Ternary lithium Battery Pack should have like (3) times the capacity of the (4) 12V 12AH SLA's that I had in the kart
...it should propel the kart a bit faster (higher initial voltage)
...& also, should be able to handle the "strain" (ie. voltage drop) from hard accelerations better too

For comparison, the 48V 12AH SLA pack would be (12) 12V 12AH modules, which all together
...would occupy a space (~16"W x 18"D x 4"H)
...weigh over 100lbs. (~10lbs. x 12 = 120lbs.)
...& cost ~$300.00 (12 SLA's x $25.00ea. = $300.00)

Whereas this Ternary pack
...occupies ~11"W x 7"D x 3.5"H
...weighs ~20lbs.
...but, only costs ~$75.00 more
...& don't forget, it includes the matching charger

Well, let's see what she can do

https://www.youtube.com/watch?v=ZNq-eSi_bBo

 

[JTSpeedDemon]

TBH the roll hoop is killing the race kart vibe for me. But still, I like it!

 

[Functional Artist]

TBH the roll hoop is killing the race kart vibe for me. But still, I like it!

The roll bar/seat back is mainly a "safety device"
...but, it's also kinda "my signature"

All of my karts have 'em
...but, I'm glad you like it

Man this thing "zips around" great
(I guess must have the "glexis dialed in pretty good)
So here's a recap:
It looks like the top speed with (4) 12V 15AH SLA's was ~17 MPH
...& I "ripped around" ~40 min. while draining ~345 Wh out of 'em

The top speed with the 48V 35AH Lithium battery pack was ~19 MPH
...but, I only rode 'er ~30 min. & drained ~250Wh out of 'er before I aborted the test due to an area of the battery pack "heating up"

 

[landuse]

The roll bar/seat back is mainly a "safety device"
...but, it's also kinda "my signature"

All of my karts have 'em
...but, I'm glad you like it

Man this thing "zips around" great
(I guess must have the "glexis dialed in pretty good)
So here's a recap:
It looks like the top speed with (4) 12V 15AH SLA's was ~17 MPH
...& I "ripped around" ~40 min. while draining ~345 Wh out of 'em

The top speed with the 48V 35AH Lithium battery pack was ~19 MPH
...but, I only rode 'er ~30 min. & drained ~250Wh out of 'er before I aborted the test due to an area of the battery pack "heating up"

Nice work FA!!

 

[Functional Artist]

I've been doin' more testin'

First, I removed the right motor & chain

I wanted to test this lithium battery powering just (1) 48V 1,000W motor
...to see if the corner/output wire area would still get warm/hot
...& to get an idea of how much energy it holds

Well, after (3) days (in eve, after work) of hard drivin', I can (happily) report that there has been NO heating issues (this time)
...but, after only draining 936Wh out of the pack
...& with the meter still showing the battery @ 49.17V
...I had to stop this test early too

This time we had a mechanical failure
...snapped a spindle off

https://www.youtube.com/watch?v=3QizLJe9Zm0

 

[Functional Artist]

Back to our test

I took everything apart, cleaned 'er up & welded the spindle bracket back on
...then, I resumed the test, that I was doin' on this 48V 35AH lithium battery

So, I ended up gettin' ~1,350 Wh of energy out of this pack
...with the meter still showing it @ ~46V
...& she was still "zippin'" around pretty well

* Plus, I can confidently say that this battery seems to power (1) 48V 1,000W motor really well, without any of the temp issues, that I encountered when tryin' to power the (2) 1,000W motors

Yup, I got a video for ya

https://www.youtube.com/watch?v=n_lB8p-CLOY

 

[Functional Artist]

Upgrade to 60V 2,000W brushless motor

Well, I got all of the 48V stuff removed from the kart

So, up next, Ima gonna try/test a 60V 2,000W motor on 'er

This 60V 2,000W motor is about the same size as the 48V 1,000W brushed motor
...but, the controller is HUGE

Here is info in the motor (~$100.00)
BM1024 2000W 60V motor
Specs:
- 60V DC
- Rated 2000 Watt, 42 amps
- Rated 5600 RPM
- Chain drive (11 teeth sprocket) #8 chain 8mm pitch
- Type of motor: DC, Brushless (BLDC)
- Reversible

https://www.ebay.com/itm/2000W-Watt...IOnTopCombiner&_trksid=p2563228.c101112.m1982

...& the controller (~$100.00)
YALU YBW3000V72SG=CDC BrushlessRYCTKBC
48 to 72 Volts, rated, 3000 Watt
70 amps Peak (almost 5000W peak!)
120 °
Connecting diagram: Please look at picture showing cables and functions
Connects to:
Battery
Motor (3 cables, power)
Motor (5 cables, hall effect)
Power lock switch
Brake switch
Reverse switch
Speed Signal
Throttle (hall effect throttle)

https://www.ebay.com/itm/Controller...347596?hash=item263294760c:g:y-cAAOSwMFVfRdRf

 

[Functional Artist]

I got the motor & that HUGE speed controller mounted
...& now, workin' on gettin' everything connected up

 

[landuse]

Looking sweet!!

 

[Functional Artist]

Thanks!

Before connecting this thing to a 60V power supply I need ta add some circuit protection.

This is a 2,000W motor powered by a 60V battery pack
...so, the motor should draw ~33A
(2,000W/60V = 33.3A)

So, I figured I'd get a 50A breaker
...a bit bigger, to be able to handle the max/hard acceleration amperage or "spikes"

Midnite Solar MNEPV50 50 Amp 150 VDC Din Rail Mount Breaker - 13mm Wide

• 50 Amp
• Wire Size Range - 14 to 6 AWG
• 150VDC din rail mount breaker
• 13mm wide
• 10,000 AIC
• 3, 5, 6, 8,10,12,15, 20, 30, 40, 50, 60, 63 amps Available - This breaker is 50 amps
• MNEPV breakers are the same as CBI QY breakers available elsewhere except they are 150VDC
• ETL listed in the US and Canada
• Fits din rail 35mm x 7.5mm
• Can also, be used as a DC circuit switch for circuits requiring less than 50 amps
• For use in Magnum MMP Panels, Magnum MP Panels, Midnite Solar Inverter Panels, Midnite Solar combiner boxes
• Snaps easily onto the DIN rail and then is secured by pressing in a small securing lock on the bottom of the breaker
• Great for providing current protection for charge controller outputs up to 150VDC.

It's best to connect/mount it, as close to the power supply (battery) as possible
...so, I'ma gonna mount it, right next to the positive (+) terminal, on the 1st battery

Next, I need a way to mount it
...& also, to provide some terminal cover/protection

Hmmm, I think
...(2) pieces of 1/4" thick clear plastic
...cut a bit oversized
...bolted together
...with the breaker "sandwiched" in between
...& then, Velcro'ed in place
should do

 

[Functional Artist]

I've been thinkin' about the need for a contactor &/or a precharge circuit.

Hmmm, I wonder what the inside of this controller looks like?
...so, I opened 'er up

I did a video to record/document the journey

 

[Functional Artist]

The wiring definition, for this controller, does not show, list or require a contactor or a precharge circuit.
...so, I was wondering "if" they may be incorporated into the controller.
(these components are usually required on "bigger"/ higher voltage controllers like this)

But, I would have to say, NO there is NOT any type of contactor, inside of the controller
...because when we looked inside of the controller, we could see that the power cables (that connect to the batt pack) are directly connected to the "rails".
...& if there is not a contactor (switch) in there then, there can NOT be a precharge circuit either.

Why would there be a need for a contactor
...&/or a precharge circuit if the wiring definition (from the factory) does not show or require them?

Well first, a contactor is basically a big beefy electronic switch/relay.
(a relay is a low power, electronic switch that, when activated, connects a bigger high power switch)

The contactor carries the flowing current, from the battery pack to the motor/controller
...but, also, can sever that flowing current, when the relay is "switched off"
(like in a "run away" situation, or when the low voltage threshold has been reached)

A precharge circuit is basically just a resistor, connected across the terminals of the contactor, that only allows a small amount of current flow thru at a time.
It's job/function to slowly fill up the capacitators, in the speed controller, so that they don't get "slammed" with a huge "inrush" of current when the contactor is first switched on.

* An additional benefit of adding a precharge circuit to this system, besides protecting the capacitators, is that by "equalizing" the voltage of the batt pack & the capacitators before the contactor is switched on, it would/should not have to deal with a huge "inrush" of current, thus protecting the contacts inside of the contactor.

Let's see what I can "conjure up"