Pulse Ultra Defender LiPo Back Up System - Control Board w/ External LED & LiPo

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Sophisticated, compact, light weight and incredibly advanced, the Pulse Defender is your ultimate line of defense from in flight power loss, which can lead to the complete destruction of your aircraft. With the Defender, Pulse offers the ultimate level of protection you simply should never fly without. Designed to defend...

Sophisticated, compact, light weight and incredibly advanced, the Pulse Defender is your ultimate line of defense from in flight power loss, which can lead to the complete destruction of your aircraft. With the Defender, Pulse offers the ultimate level of protection you simply should never fly without.

Designed to defend your aircraft from destructive in flight power loss, the Pulse Defender is a battery back up system that brings simplicity to the fore, offering an ultra simplified plug and play solution with maximum levels of cutting edge safety. The Defender allows a powered off glide or auto rotation in the event of full power loss, providing crucial electrical power to your receiver, servos and flight controller.

Self charging and ready to protect, the Defender monitors on board voltage every millisecond of your flight, and in the event of a BEC or main flight battery failure, the Defender steps in with a 500mAh 2S LiPo back up power source, providing crucial power to your on board electronics, allowing you the last chance option to get your aircraft on the ground, safe and sound.

Consisting of a tried and true 2S 7.4V 500mAh LiPo battery with ultra sophisticated circuitry in the mix, the Defender is a must have device for heli and airplane pilots alike, providing the last line of defense your aircraft deserve.


Power failure is your greatest nemesis, and an in flight power loss can result in complete destruction of the aircraft you have so much invested in. Designed with a high discharge 2S LiPo battery with ultra sophisticated monitoring circuitry, the Defender steps in when power is lost, offering a last line of defense when you need it the very most.

Best of all, the Defender adapts to your system, providing the voltage your system requires. Whether you're running a high voltage 8.4V / 7.4V system or a lower voltage 6V system, the defender will analyze the voltage of your system at start up and provide the voltage required to keep your system set at the proper voltage.


Designed to charge and balance while in use, the Defender maintains full voltage in flight, ready to protect in the event of power failure. Featuring a 2C charge rate and a 500mAh 2S 7.4V battery, the Defender is ready to step in when failure takes place.


Monitoring your flight every single millisecond, the Defender is working overtime to keep you safe. Designed to instantaneously step in when voltage is lost, the Defender keeps everything in check, one millisecond at a time.


Designed to defend, the Defender keeps tabs on your BEC / Receiver Power output. If a transient voltage drop takes place, the Defender will instantaneously step in, providing full voltage, and will alert this voltage drop via a rapid flashing LED light.


Know your Defender is working with the on board power LED light. When you see the LED light with a steady flash every 4 seconds, your Defender is at work, ready to protect.


If the Defender senses a voltage drop in flight, the Defender board and auxilliary LED board will rapidly flash, instantly alerting you that power has been lost.

Pulse Defender Usage, Warnings & Info:

The Pulse Defender was designed as a safety back up device to offer continuous power to the receiver or flight controller when an electrical power loss takes place. The Defender does not offer power to the motor - it is a redundant back up device, allowing the option of a powered off glide or auto rotation in the event of full electrical power loss.

Do NOT use the Defender as a main power supply for your servos or electronics, as the Defender is designed as a backup defense only, and cannot be used as a main power supply.

Before Your Flight:

Be sure the Defender has been fully charged before usage. After being charged, power up all electronics and test electronics before the Defender has been activated, thus making sure all systems are operating normally. Plug in the Defender to your receiver or flight controller and press the black power button to power the Defender, which will allow the Defender to protect your aircraft in the event of a full electrical power loss while in flight.

After Your Flight:

Once your flight has ended, unplug the Defender from your receiver or flight controller to protect the battery from being discharged while not in use. If the Defender is left plugged in for a prolonged period of time without receiver / BEC power, the battery will be irreversibly drained in power, which will result in permanent and terminal battery damage.


Do not leave the Defender plugged into the receiver or flight controller after the flight has ended. Leaving the Defender plugged into the receiver or flight controller for prolonged periods of time (without main flight pack power) will deeply discharge the battery and damage the Defender battery, which will not be covered under warranty.

Defender Specifications:

Battery: Pulse 500mAh 2S 7.4V / 2C Charge Rate
Weight: 38g (Including Connectors)
Size: 55mm x 31mm x 18mm (LxWxH)
Pulse Defender Usage Instructions & warnings - Please Read Carefully!
The Pulse Defender is designed as a battery backup for in flight power loss, allowing for an auto rotation or dead stick landing when BEC / receiver power is lost. Utilizing a 2S 7.4V 500mAh LiPo battery, the Defender will power your receiver, servos and flight controller (if applicable) when BEC / receiver power is lost.

The Pulse Defender is not a substitute for sustained receiver power. To save weight and reduce the overall footprint, the 500mAh 2S 7.4V LiPo battery does not have the capacity for long duration power supply, so be sure that the Defender is only used for it's main design purpose - a battery back up system in the event of a BEC or receiver power failure.

The Pulse Defender Consists of the Below:

(1) Pulse Defender Main Board
(1) Pulse 2S 7.4V 500mAh LiPo Battery
(1) Auxiliary LED Light

Defender Usage & Functionality:

The Defender is designed for easy use & functionality, making use & application of the Defender within your aircraft a seamless & simple process. Please carefully review the below information to make sure the Defender is properly utilized to provide the maximum levels of safety with the aircraft of application.

Before 1st Use:

The Pulse Defender ships with a storage charge of 3.7V - 3.85V per cell and will require charging before use. Charging can take place via a dedicated LiPo battery charger, allowing the 2S 7.4V LiPo battery to be fully charged for use. This will be the only time the battery needs to be charged via normal day to day use, as the Defender will charge its battery by drawing from the BEC power or receiver pack power.


- Secure the Defender in your aircraft in a location that allows easy access of the Power Button on the main board, as the Defender will need to be powered on before the flight and powered off once the flight is finished.

- Allow access for the LiPo balance lead to be plugged into and unplugged from the main board. The Defender draws a small amount of power, and if the battery is left plugged in without BEC / receiver pack power, the LiPo battery will be drained and damaged.

- If using the auxiliary / optional LED light, locate this in an area that is visible from outside the aircraft. This is especially important with receiver battery powered aircraft, as any receiver battery power failure will shift the power load to the Defender, and the LED light will flash rapidly, alerting the pilot of the power failure. If this is not visibly seen, the pilot may continue flying the aircraft using the Defender power source, which is not designed for sustained power.

Connecting the Defender:

-Connect the Defender to your receiver or flight controller via the power wire - any available servo / battery port via the receiver or flybarless unit can be used. If a port is not available, a Y-Harness can be utilized.

-Connect the Defender LiPo battery to the Defender board via the white balance plug.

Powering the Defender On & Off:

- Before powering on the Defender, power on the BEC or receiver pack and verify all electronics function correctly, such as servos & flight controller. Once verified, power on the Defender by pressing the small, black power button located on the Defender board.

- When the Defender is powered on and functioning properly, the LED light via the board (and auxiliary LED light, if used) will slowly flash every (4) seconds, indicating the Defender is ready to provide power if a BEC / receiver battery failure takes place.

- If you would like to test the Defender, make sure the Defender is powered on, and simply remove BEC or receiver power to verify the Defender is properly functioning. Servos, receiver & flight controller should remain functioning when BEC or receiver power is removed.

- When the flight has ended, power off the Defender by pressing the small, black power button located on the Defender board.

- If flights have ended for the day, unplug the white LiPo battery balance plug from the Defender board to prevent the Pulse Defender battery from being depleted and damaged.

LED Light Status Info:

- Slow Red LED Flash: The Defender is working normally and is in "Defender Mode," awaiting a voltage drop or complete voltage loss.

- Steady Red LED Flash: The Defender battery is charging by pulling power from the BEC or receiver pack.

- Ultra Rapid Red LED Flash: The Defender has sensed a voltage drop or voltage loss and is now powering the aircraft electronics.

Defender Battery Voltage:

- The Pulse Defender utilizes "Smart Sense" technology to read  and replicate the input voltage of the BEC or receiver pack voltage. In the event of a failure, the Defender will apply the correct voltage the system requires based upon the initial voltage readings.

- If any BEC voltage adjustments are made for any reason, the Defender does not need to be reset, as the Defender will always read the BEC or receiver pack voltage before any power is applied, thus protecting the electronics from any excessive voltage the Defender can deliver.

Defender Storage:

- If the Defender will not be in use for more than (2) weeks, we recommend placing the Defender into a storage charge mode of 3.7V - 3.85V per cell, as storing any LiPo battery at full charge for greater than (2) weeks can subsequently damage the battery, and is not safe.

- If the Defender is placed into a storage charge mode and later used again, be sure the Defender is fully charged via a LiPo battery charger before 1st use of the Defender.

Defender Warranty:

The Pulse Defender battery is covered by a (3) month manufacturer warranty, with the Defender board being covered by a (1) year warranty. This warranty is based upon the noted time from date of purchase and is not based upon how many times the unit has been utilized.
Warranty will be voided regarding the below actions:

- Crash damage

- Improper charging

- Battery being stored at full voltage with no storage charge

- Battery being depleted by being left plugged into board while not in use


- Only utilize a dedicated LiPo battery charger to charge the Pulse Defender, as improper charging can lead to battery damage and or fire.

- Due to fire risks of LiPo batteries, we do not recommend the Defender to be stored in the aircraft while not in use.

- Due to the fire risks of LiPo batteries, store the Defender in a safe location free of any combustible materials. We recommend a LiPo bag or LiPo safe.

- Do not store or charge the Defender inside a home, garage, vehicle or any area with combustible materials.

- Be sure to disconnect the Defender battery from the Defender board after aircraft usage has ended for the day. If the Defender battery is left plugged into the board, the battery will be depleted and damaged.

- If the Defender is not used for more than (2) weeks time, place Defender into a storage charge mode - 3.7V - 3.85V per cell. Storing the Defender at full charge will damage the battery and poses a risk for fire.

Damage Limitations:

Pulse Battery and all other distributors and retailers of Pulse batteries cannot be held liable for misuse, abuse or negligence relating to the possession or usage of the Pulse Defender. Pulse Battery and all other distributors and retailers cannot be held liable for any aircraft damage, injury or death relating to aircraft crashes, including fires or property damage. Due to the possibility of LiPo battery fire, it is the sole responsibility of the end user to safely use, charge and store the Pulse Defender to prevent any fire or subsequent fire damage, injury or death resulting from a LiPo fire. All warranty claims relating to the Pulse Defender will be validated based upon the (3) month battery warranty and (1) year board warranty from date of purchase. Any valid warranty claim will be honored in regards to direct replacement of unit at hand. Ancillary crash damage, repairs or aircraft values cannot be honored relating to warranty support.


Pulse Defender vs. Other Guard
The Pulse Defender offers the below capabilities & functionalities, offering superior performance when compared to the OptiGuard back up system:

  • Reads continuous voltage every millisecond for faster reaction when power is lost
  • Utilizes an analog chip set instead of an MCU unit, allowing faster overall read & response
  • Supports weak BEC if a weak BEC is recognized in flight, providing power for transient power loss if a BEC issue is at play

Why Power On / Off vs. Auto?
The Defender uses a manual "On / Off" feature versus an "Auto On" system, as we felt this option gave the end user the best overall functionality and protection, such as:

  • Allows the user to optionally power on / off unit at will based upon need or demand
  • Prevents battery drain / damage by allowing unit to be shut down, versus "auto on" that can't be shut down
  • Protects electronics in the case of voltage back feed, as an "auto on" system would power system and potentially damage electronics / mechanics










0.3 lb

Product Spare Parts


Customer Reviews

Based on 27 reviews
Jason J.
Great Buy

Works as expected. A must have backup if flying expensive birds.

Mike B.

Works perfectly, hope it never needs to turn on ,but a great bit of it insurance for your plane

Works great

Easy to install and operate
It could use a slightly larger off button
The heat shrink was covering the button and required trimming around it.

juan e.g.c.

Exelent backup. Dont like the solder of receiver cable.

Bruce H.
Pulse Defender - Excellent product

I have installed these on all my 6 cell foam airplanes. it is a cost effective option to installing a smart two battery feature. I bench check every time I go to the fly and it works on the bench every time.

Great affordable backup

Can’t beat the price for the protection

Steven P.
Bench test

After checking the defender out I realized there is a need for it.
I bench tested the unit with a trex 450 with a bx7210. Removed main and tail blades, installed the defender. Powered up system, then disconnected the flight battery, i still had full servo and gyro function and could theoretically still auto safely. Haven't had a real time failure, hope not to , but I'm ready.

Marco C.
Saved my helicopter 2 times already

This is a nice and affordable backup power unit. I highly recommend running a backup power system because it is a matter of time until you have a power loss on a helicopter. The Pulse defender is very easy to use and maintain. Make sure you unplug the balance cable when you are not using it, this will make you battery last more than one season.

Denard D.

Works like a champ

Backup power supply

Great investment for the big helis. Still have power on the servos to land if the ESC fails. Light is bright and charges while it’s flying.