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· Registered
984 Posts
Yup, we need more info
...a lot more info

Quick question:
Why would you/anyone purchase a 24V battery pack power a 48V motor?

If it does work (or function) it will only be able to give your motor ~50% of what it wants & is designed for
...a 48V battery pack is what you need

You shouldn't need to use a contactor on a 48V 1,500W motor.

Contactors are usually only used on motors that are over ~3,000W

Since I can't direct you to ANY of my old threads (at the moment)

Here is a You Tube video of a go kart that I put a 48V 1,800W BLDC motor on

Hope it helps

· Registered
984 Posts
Contactors are (usually) necessary or used for
...high amp systems (60V & up)
...or if, using big (high wattage) motors (over ~3,000W)

The specs says for your KEB48201X speed controller says:

"Supply current, PWR, 150mA.
...the speed controller (itself) draws 150mA.

"Controller Supply Voltage Range 18V - 90V"
...that's the voltage range that the speed controller can handle

"Configurable battery voltage range,B-. Max operating range 18V - 60V", anywhere from 24V - 48V should power it

* Different manufacturers do things "differently", you/we'll have to go by the Kelly diagram

* I have had many conversations with Fran @ Kelly Controls
...she is very helpful (but, can't help everyone "step by step"
...that's what were here for (I think)

· Registered
984 Posts
Actually both diagrams are about the same
...the simple one just doesn't show the contactor or brake connections

Look at the diagram on page 8 of the manual, it looks like

The bar connectors on the front of the controller are for your main or "Big Power" connections
...that's where your power in (from battery pack)
...& power out (to the motor) connect

B+ -connect to your battery pack positive (+)
B- -connect to your battery pack negative (-)
A -connect to the big motor wire (U/1/A phase)
B -connect to the big motor wire (V/2/B phase)
C -connect to the big motor wire (W/3/C phase)

The J1 plug is for your "Small Power" connections
...that's where everything else connects

1. PWR: controller power supply where you connect battery pack voltage (thru an On/Off or key switch) to turn the speed controller on or off

2. RTN: signal return, or power supply ground

3. RTN: signal return (GND)
...both are where you can connect any negative wires (to complete a circuit)

4. 12V high-level brake & motor temperature input
...connect to a Thermistor (motor temperature sensor)

5. Throttle analog input, 0-5V
...connect to throttle switch (signal)
6. Brake analog input, 0-5V
...connect to brake lever switch (signal)

7. 5V: 5V supply output, <40mA supply 5V power (for throttle & brake signals)

8. Micro SW: Throttle switch input
9. Reverse switch input
...connect to reverse switch

10. Brake switch input

11. Hall phase C small motor wire

12. Hall phase B small motor wire

13. Hall phase A small motor wire

14. RTN: signal return
...another GND (if needed)

· Registered
984 Posts
What kind of batteries are we talking about?
...with a peak current of 10A?

I have pulled 100A out of (4) 12V 12AH SLA's (many times)

Also, what (make/model of 1,500W BLDC) motor do you have?

Your speed controller has a max current of 160A & a continuous current limit of 60A

But, keep in mind that your 1,500W BLDC motor should draw about the same as the 1,800W BLDC on the e-Lemon-aid kart (in the video that I linked earlier)

The meter showed that it drew
...~30A @ take off
…& ~10A consistently

· Registered
984 Posts
Your very welcome

Those batteries should power that motor & controller, just fine

I don't have any knowledge of that specific motor
...but, (as I said) a 1,500W BLDC should have "roughly" the same characteristics/performance as the 1,800W BLDC (in the video)

Your motor may draw ~35A at take-off but should drop considerably once it's/your "up to speed"

The speed controller is how "you" control the RPM's of the motor

0 throttle = 0 RPM's = full stop
1/4 throttle = 25% RPM's = 25% available speed
1/2 throttle = 50% RPM's = 50% available speed
3/4 throttle = 75% RPM's = 75% available speed
Full throttle = 100% RPM's = max available speed

* Also, these Kelly controllers are "configurable"
...which means that you can "go in" & make adjustments

(don't worry about it right now, we'll get into that later)

Do you have the "programming cord" to connect the speed controller to a computer?

· Registered
984 Posts
The KEB48201X is your speed controller (brain box) controls the power (amps) going into the motor, which dictates the speed (RPM's) that the motor turns.

You control the motor, thru the speed controller, with a throttle.
...that's what connect to the throttle input

The throttle can be either
...a twist throttle (like on a motorcycle, on the handle bars)
...a thumb throttle (like on an ATV or jet skis handle bars)
...or a pedal throttle (like on golf carts)

Here is an example thumb throttle

Do you have a throttle?

· Registered
984 Posts
Yes, a switch between the battery & speed controller is necessary. gives you the ability to turn the speed controller on or off.

It doesn't have to be a key switch, any 12V toggle switch will do this circuit will only be carrying ~150mA.
(using a key switch allows you to secure/lock your project)

The contactor is a totally different switch is a "big/beefy" switch between the speed controller & motor

· Registered
984 Posts
Well, that sucks!

I think you just found "the spot" where the other group got stuck
(the one that was previously working with this controller & could not get it to work)

Are you sure the controller even works (Dumb question, I know)

I guess now, would be a good time to open a dialog with Fany @ [email protected]

Let her know "I think she's a her" that you followed the diagram, that she referred you to, explain everything that you have done & what happened when you switched it on.

Let us know how it goes.

· Registered
984 Posts
If the controller senses (receives) lower than required voltage
...the "low voltage protection" function would "kick in" (no green light)
(to help protect your battery pack)

The green light only lights when everything is functioning normally's main job is to tell you, "if" your good to go

1.) What is the voltage, that you have, going in to the controller?

2.) What throttle do you have

3.) & how do you have it connected?

It always makes me shiver when someone says "I shorted..."

...always use a small fuse (like 3A or 5A)

That way, if it's a mistake (hopefully) the fuse "pops" & not the component that your testing your "idea" on

· Registered
984 Posts
4x 12v batteries in series gives 48v that means neg from batt1 to pos batt2, neg batt2 to pos batt3, neg batt3 to pos batt4,
if 1 battery is given as 12v 10a the you have 48v 10a, for more amps you have to use larger batteries if you want to stay with 48v
larger batteries would give more capacity
...but, not "actually" more amps

I have used many 12V SLA batteries usually from 12V 12AH up to 12V 35AH

The 12V 12AH SLA's say (on the side of the battery) "Initial Current (less than 3.6A)
...but, I have pulled nearly 100A out of them many times

There is a tremendous voltage sag (watch the meter in the video)
...but, they do it

Here is a video where I did some "against the wall" tests

The tests were to see what kind of amps a ZY1020 48V 1,000W motor would draw
...but, it also shows what these small SLA batteries are capable of

· Registered
984 Posts
Maybe hook up your programming cord
...go in & do some exploring
...just to see what everything is "set at"

If the "Low battery Cut-off Voltage" is set at anything higher than 48V wouldn't get a green light @ turn on
...but, it should also flash a (1,3 red) error code

The manual covers
...GREEN OFF (no power/switched off)
...GREEN ON (normal operation)
...GREEN & RED are both on (software issue, too low or high of voltage or controller damaged)
...but, it doesn't mention a solid red error situation

· Registered
984 Posts
Speed controllers (most electronics) have "safe"/usable" voltage ranges
...because the voltage changes as the battery is drained.

The voltage level of a 48V SLA battery pack goes from
...~53V (fully charged) ~40V (lowest level you can "safely" drain the battery down to without damaging it)

Safe voltage ranges
(for most SLA's)

12V = 10V - 13.3V
24V = 20V - 26.6V
36V = 30V - 39.9V
48V = 40V - 53.2V
60V = 50V - 66.5V

So, maybe try
...setting the low voltage ~40V & the high voltage ~ 53V

If you still get hall sensor error maybe
...disconnect the throttle
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