Xbox Controller Modification

Wireless-Charging Xbox Controller

A controller is most useful when it is already charged and ready to use. In this project, I modified an Xbox Series X|S controller by installing a rechargeable lithium battery, a wireless-charging receiver, and a regulated 3-volt power supply inside the original housing.

The finished prototype powers the controller normally and begins charging when it is placed on a compatible wireless-charging pad. The current circuit uses separate boost and buck converters, proving the concept while leaving room for a more efficient future revision.

Modified Xbox controller with integrated wireless charging

1. Project Goal

The goal was to replace disposable AA batteries with an internal rechargeable battery that can be charged without connecting a cable to the controller. When the controller is placed on a wireless-charging pad, the receiver coil transfers power to the charging circuit and recharges the internal battery.

Rechargeable power A single-cell lithium battery replaces the two disposable AA batteries.

Wireless charging A receiver coil inside the battery cover collects energy from a compatible charging pad.

Stable controller voltage A DC-DC conversion stage supplies approximately 3 volts to the controller.

Serviceable design A removable connector allows the battery cover and charging coil to be disconnected during maintenance.

Battery-safety warning: Lithium-ion and lithium-polymer cells can be damaged by short circuits, overcharging, deep discharge, puncturing, overheating, or incorrect polarity. Use a protected cell or a suitable protection circuit, insulate all exposed connections, and never use a damaged or swollen battery.

2. Why the Controller Cannot Use the Battery Directly

A standard Xbox controller normally uses two AA batteries connected in series. With approximately 1.5 volts per cell, the controller receives around 3 volts.

A rechargeable single-cell lithium battery behaves differently. Its nominal voltage is approximately 3.7 volts, and a fully charged cell can reach approximately 4.2 volts. Connecting this voltage directly to the controller would exceed the normal AA-battery supply voltage.

Power source	Typical voltage	Suitable for direct connection?
Two alkaline AA batteries	Approximately 3.0 V when new	Yes, this is the controller’s normal battery configuration.
Single-cell lithium battery	Approximately 3.0 V to 4.2 V	No. The voltage must be regulated before it reaches the controller.
Regulated converter output	Approximately 3.0 V	Yes, after polarity and voltage have been verified.

Undervoltage protection: The battery must not be discharged too deeply. Use a DC-DC converter with a suitable low-voltage cutoff, a protected battery, or a separate protection circuit. For this type of single-cell lithium system, the load should stop before the cell falls below the safe minimum specified by the battery manufacturer.

3. Circuit Overview

The prototype contains two connected electrical paths. The charging path transfers energy from the wireless receiver to the battery. The power path converts the battery voltage into a stable supply for the controller.

Wireless-charging pad energizes the receiver coil

Receiver and charging circuit recharge the single-cell battery

Battery supplies the DC-DC conversion circuit

Boost converter raises the battery voltage to 5 V

Buck converter regulates the voltage down to 3 V

Controller receives the regulated 3 V supply

Charging-module warning: A wireless receiver that produces 5 volts is not automatically a lithium-battery charger. Use a module explicitly designed for charging a single-cell lithium-ion or lithium-polymer battery with the correct charging profile and termination voltage.

4. Required Components

For the working prototype, I used the following components:

Xbox controller Xbox Series X|S controller with removable battery cover.

Wireless-charging receiver Receiver coil and electronics suitable for the selected battery-charging arrangement.

Rechargeable battery Single-cell lithium-ion or lithium-polymer battery with suitable capacity and physical dimensions.

Boost converter Raises the battery voltage to approximately 5 volts for this prototype.

Buck converter Reduces the boosted voltage to a stable 3-volt controller supply.

Protection Protected battery, battery-protection board, or converter with suitable undervoltage shutdown.

Connections Flexible wires, pin headers, removable connector, heat-shrink tubing, and insulation tape.

Tools Soldering equipment, multimeter, plastic opening tool, rotary tool, small screwdriver, and double-sided tape.

5. Testing the Wireless-Charging Circuit

Before modifying the controller, I tested the charging system separately. I connected the battery to the designated battery terminals of the charging receiver and placed the receiver coil on a wireless-charging pad.

The charging system activated and the battery began charging. Testing the circuit outside the controller made it easier to verify polarity, charging behavior, and component temperature before installation.

I currently use a standard wireless-charging pad. A future version could include a custom stand that holds the controller and aligns the coil automatically.

6. Creating a Stable 3-Volt Supply

The buck converters available for this prototype require an input voltage of at least approximately 4.5 volts. Because a single lithium cell only provides approximately 3 to 4.2 volts, the buck converter could not be connected directly to the battery.

I therefore used a boost converter to raise the battery voltage to 5 volts. A second converter then reduced this voltage to a stable 3 volts for the controller.

Prototype limitation: Converting the voltage twice creates additional power loss. A more efficient final version should use a suitable buck-boost converter that can generate a regulated 3-volt output directly across the battery’s usable voltage range.

Measurement point	Measured voltage	Purpose
Battery	Approximately 3.9 V during the test	Energy source for the complete circuit.
Boost-converter input	Approximately 3.9 V	Directly connected to the battery output.
Boost-converter output	Approximately 5.0 V	Provides sufficient input voltage for the buck converter.
Buck-converter output	Approximately 3.0 V	Regulated supply connected to the controller.

7. Completing and Verifying the Circuit

After connecting the charging and power-conversion stages, I measured the voltage at every point in the circuit. The final output remained close to 3 volts, so the prototype was ready for installation.

I temporarily disconnected the boards again because the final component positions and cable lengths depended on the available space inside the controller.

Check before connection: Measure the converter output with a multimeter before connecting it to the controller. Verify both voltage and polarity. A reversed connection or excessive voltage can permanently damage the controller.

8. Disassembling the Controller

I first removed the side grips using a plastic opening tool. The battery-compartment sticker hides one of the housing screws, so I removed the sticker and then loosened the hidden screw together with the four remaining screws.

After all five screws were removed, the two housing sections could be carefully separated. Opening the housing slowly reduces the risk of damaging clips, wires, buttons, or internal components.

9. Modifying the Battery Compartment

The original AA-battery structure occupied too much space for the rechargeable battery and converter boards. I used a small rotary-tool saw to remove the internal section of the battery compartment.

I removed only the material required for the electronics and kept the mounting features used by the original battery cover. This allows the cover to remain securely attached after the modification.

Mechanical warning: Remove the battery and all loose electronics before cutting or grinding the housing. Wear eye protection, avoid damaging screw posts and clips, and clean all plastic dust before reassembly.

10. Preparing the Wireless-Charging Receiver

I added pin headers to the receiver board and installed a removable connector in the battery wiring. The charging coil remains attached to the battery cover, while the connector allows the cover to be separated from the controller during maintenance.

This arrangement prevents the coil wires from pulling directly on small solder joints whenever the battery cover is removed.

Receiver board Mounted inside the available battery-compartment space.

Charging coil Positioned against the battery cover for good alignment with the charging pad.

Removable connector Separates the cover and coil from the rest of the controller.

Strain relief Prevents movement of the cover from stressing the solder joints.

11. Connecting the Controller

I soldered two wires to the controller’s battery power terminals and connected them to the regulated 3-volt output of the DC-DC circuit. The polarity was checked before soldering and verified again before the controller was powered.

The wires were routed away from buttons, screw posts, trigger mechanisms, and housing edges. Exposed solder joints were insulated to prevent accidental contact with the circuit boards or shielding.

Recommended practice: Add an inline connector between the controller and converter output. This makes troubleshooting easier and allows the controller electronics to be disconnected without desoldering the power wires.

12. Installing the Electronics

I secured the converter boards with double-sided tape and checked that they could not move when the controller was handled. The battery was placed inside the modified compartment and connected to the converter input.

The wireless-charging receiver and coil were then connected to the battery. Before closing the housing, I confirmed that no wires were pinched and that the buttons, triggers, and battery cover still moved correctly.

Insulate the converter boards and exposed solder joints

Secure the boards so they cannot move inside the housing

Install and secure the battery without bending or compressing it

Connect the receiver, battery, converters, and controller

Measure the final controller supply voltage again

Close the housing and reinstall all five screws

13. Final Test

The controller powers on normally and connects to the Xbox without any problems. When it is placed on the wireless-charging pad, the receiver activates and the internal battery begins charging.

The prototype successfully demonstrates the concept: the original controller can be powered from an internal rechargeable battery and recharged wirelessly without modifying its external charging port.

The main improvement for a future version would be replacing the separate boost and buck converters with one efficient buck-boost converter. A purpose-built charging stand could also improve coil alignment and make the controller easier to place correctly.

Completed wireless-charging Xbox controller on a charging pad

Completed prototype charging on a compatible wireless-charging pad.

14. Current Limitations and Future Improvements

Single buck-boost converter Replace the two-stage conversion circuit with a converter designed for a single lithium cell.

Lower standby current Select converters with low quiescent current to reduce battery drain while the controller is not in use.

Custom charging stand Build a stand that holds the controller securely and aligns the receiver coil with the transmitter.

Improved mounting Use a compact custom PCB or printed carrier instead of mounting separate converter modules with tape.

Temperature monitoring Confirm that the battery and charging electronics remain within their specified temperature limits.

Battery indication Add a reliable way to monitor the actual battery state of charge or charging status.

15. Frequently Asked Questions

Why not connect the lithium battery directly to the controller?

A fully charged single-cell lithium battery can reach approximately 4.2 volts, while the controller is designed around a supply of roughly 3 volts from two AA batteries. A regulated converter keeps the controller supply within the intended range.

Why does the prototype use both a boost and a buck converter?

The available buck converter required a higher input voltage than the battery could provide. The boost converter first raises the voltage to 5 volts, and the buck converter then reduces it to 3 volts. This works for testing but is less efficient than a suitable buck-boost converter.

Does every wireless-charging receiver safely charge a lithium battery?

No. Some receivers only provide a regulated output, commonly 5 volts. A lithium battery requires a dedicated charging circuit with the correct constant-current/constant-voltage charging profile, termination behavior, and protection.

Why is undervoltage protection necessary?

If the controller continues drawing current after the battery reaches its safe minimum voltage, the cell can be over-discharged and permanently damaged. A protected cell, protection board, or converter with low-voltage shutdown prevents this.

Can the original battery cover still be removed?

Yes. The charging coil is attached to the cover and connected through a removable plug. This allows the cover to be detached without pulling on the receiver-board solder joints.

Final Thoughts

This project shows how wireless charging, lithium-battery management, voltage conversion, and mechanical modification can be combined in one compact build. The prototype works, but battery safety and power-conversion efficiency are more important than simply fitting the components into the housing.

A future revision with a low-loss buck-boost converter, integrated protection, and a custom charging stand would make the modification cleaner and more practical for everyday use.