Blog: IMPORTANT NOTICE: Xrotor 45 Amp 4-1 usage recommendation.

on octubre 17, 2018
Xrotor 45A 4-1 ESC usage recommendation.
We appreciate the feedback the community has provided regarding the Xrotor 45 amp 4-1 esc. We have been taking note of your emails, service calls, and communication with our team pilots. Thank you.
HOBBYWING engineering and production staff will continue to review the Xrotor 45amp 4-1 as crucial and important part of our drone racing and freestyle line up. Thus far, it appears that failures outside the normal have some basic usage trends that could be related to the precautions mentioned below.
For all applications, please note the following.
1. Power capacitor must be installed. Every Xrotor 45amp 4-1 includes 2 power capacitors. One larger, and one smaller. The larger capacitor should be used for 5s-6s lipo, the smaller capacitor can be installed for 4s-5s lipo directly on the PCB (ESC), not by a power plug. Failure to use the included power capacitors will result in damage to your ESC.
2. BL_Heli_32 ESC settings can cause damage. Default settings should be used.
3. Motor KV ratings and prop size/pitch combinations recommendations.
- 4s Lipo using 5 inch props up to 2700KV
- 5s using 5 inch props, up to 2450 KV
- 6s using 5 inch props up to 1750 KV 
Any modification/alteration of the above setting will deem a product non-warranty. 
With any HOBBYWING product, if you have experienced and usage issues, please contact our service department directly. For customers in North America, visit - under Support to complete the form.
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Important note for LiPo Cells auto detect feature of LCD Program box

By FalconSEKIDO RC Division
on octubre 22, 2014

HOBBYWING ESCs are pre-programmed for many different parameters.

I.E.: The Xerun 120A V3.1 ESC is pre-programmed on 12 different parameters:

  • Punch
  • Timing
  • LiPo Cut-off etc.
  • #12 is LiPo Cells and its default is auto detect (automatically detects the number of cells- 2s, 3s, 4s, 5s, 6s)

Auto detect works fine if you use 2s, 4s or 6s, but not on 3s or 5s for the following reason:

  • If voltage is below 8.8v it may be treated as a 2S by the ESC
  • If voltage is between 8.8 and 17.6v, it may be treated as a 4S by the ESC (3s is between these voltages)
  • If voltage is over 17.6, it may be treated as a 6S by ESC (5s is between these voltages)

As result, if you are using 3S, its voltage is 12.6 which lies between 8.8v and 17.6v, therefore, ESC treats it as a 4S.

Default cut off is set @3.2v x 4 cells = 12.8v, therefore, the ESC automatically cuts off power even though battery is fully charged.


As result, please make sure to update item #12 (Lipo cell auto detect) if you use 3S or 5S lipo battery. 


Our engineers are looking into this issue and try to improve the situation. 






Special thanks to Luis Garcia 

Xerun 120A V3.1 ESC + V10 8.5T Motor Setup Sheets by Alan Bachman, SPD

By FalconSEKIDO RC Division
on diciembre 23, 2013

Alan Bachman, SPD has contributed his ESC setup sheets for everyone to share. 


Xerun 120A V3.1 ESC - 8.5 Modified 2wd SCT_Medium-High Traction


Xerun 120A V3.1 ESC - 8.5 Modified 2wd SCT_Low Traction


Xerun 120A V3.1 ESC - 8.5 Modified 2wd Buggy Mid Motor

Special note for USB Link Software: Xerun SCT PRO

By FalconSEKIDO RC Division
on diciembre 21, 2013

When users upgrade Xerun SCT Pro ESC while the Rx wire is still in the receiver (at the throttle), please make sure that the receiver output a neutral signal. 

If the throttle signal is beyond the neutral, then the ESC will ignore the communication with the Program box, it will only accept the signal from the Rx wire. 

In such a case, the LCD program box is getting stuck at the "Programming ESC" screen. (The priority of the Rx wire is higher than the programming wire) 

When upgrade the ESC, there are 2 methods: 

  • Disconnect the Rx wire from the receiver.
  • Turn on the transmitter, make sure that the throttle stick is in neutral range. Connect the LCD program box to the program port of the ESC, and then turn on the ESC.

In addition, These are some simple points that can be done wrong resulting in problems when trying to upgrade firmware. 

  • Did they attach the program box to the esc wire or through the EPP (External Programming Port) aka Fan port.
  • Did they plug the wires in with the black wire on the left side or right side
  • Did they plug their battery in before turning on the esc

What is Punch Rate and when you need it? by Alan Bachman, SPD

on diciembre 18, 2013
Can someone explain to me about punch on the v3.1 and how it works and why. I don't understand it or how to use it 17.5 motor . and what it does. .? Thanks
Some of this info is directly from the manual but I will try to add some additional details: 

Punch Rate Control: This group of settings is used to define the starting mode of the ESC. There are a number of the sub-options for this setting. The software has the option to include a dual stage punch rate, which is 
helpful in allowing a different punch setting for different areas of the forward throttle.

Note: Please note that if you use a high punch setting, you must use good quality battery packs with powerful discharge 
ability. Otherwise these modes cannot get the burst start effect as you want. If the motor cannot run smoothly (the motor 
is trembling), it may caused by a weak discharge ability of the battery pack.

2A – Punch Rate Switch Point: This setting defines the point in the forward throttle position at which the punch rate changes. 
Options: 1-99%, in steps of 1%. 

2B – 1st Stage Punch Rate: This is the level of punch used in the first stage of the punch range, before the switch point. 
Setting 1 is least punch, with 30 being the most. 
Options: 1 – 30, with steps of 1. 

2C – 2nd Stage Punch Rate: This is the level of punch used in the second stage of the punch range, after the switch 
point. Setting 1 is least punch, with 30 being the most. 

Options: 1 – 30, with steps of 1. 

My Summary:

The punch is basically what others call a current limiter. It limits the amount of initial power that is allowed to go to the motor. Most ESC have this as just a single general setting. Hobbywing gives us much more control over this setting that the competition.

The punch rate switch point is basically the percent of throttle that it uses 1st punch rate setting vs. 2nd punch rate setting. If you leave this setting at 1% then you really only need to adjust the 2nd punch rate setting. The adjustment to the 1st punch rate would not be felt in only the first 1% of throttle being used. 

For 17.5 Racing applications, since the motor is pretty mild on bottom end power, you would usually run the Switch Point at 1% and just adjust the second punch rate setting. On a high traction surface I would run this all the way up at 30 on 1st and 2nd punch rates, giving you the most bottom end power your 17.5 has to offer. 

If you are running on a super slick track you could benefit from turning the punch setting down to 10 or lower, but keep in mind you are limiting your initial on throttle power!

For Modified racing you can really use these setting to dial in the power.

You can set the switch point to say 30% then set you 1st punch rate to something low like 5 or 10 so you don't spin the tires as easily from a super low speed, where you are off the throttle a lot, however you can then set the second punch rate higher to 20 or 30 so that once the car is rolling off of a sweeper you will still have full power from 31% of throttle input and up. 

It is a great setting to fool around with if needed. 

If you are running High Traction Large open track 17.5 motor, most likely leave switch point set to 1% and 2nd Punch setting to 30 for most power available!
In a 4wd SCT class where runtime is becoming an issue due to 8 and 10 minute races becoming the norm, by adjusting the punch rates correctly you can control wheel spin and increase run time, while reducing motor temps, making a win – win setup easy to obtain!

Good Luck!

Contributed by Alan Bachman