In Part 2, we learned about power sources for various applications.
Now entering Part 3, we will discuss how to find out the specifications of devices and power sources. We will also explore how to choose a power source with a matching output capacity. Let’s get started.
How to find out the specifications of devices and power sources?
On the Maker’s Supply product detail page, you can find product specifications. Check the product detail page to find the power requirements and limits of the devices and power sources.
The N20 motor’s product specifications, as shown in the image below, list the rated voltage, current, locked-rotor torque, and rotating speed, etc. CW means clockwise.
How to choose a power source with a matching output capacity?
When choosing a power source, we need to consider the device’s voltage, power, and application.
We need to change how we pick a power source when the device voltage and current change (see the image below for power source types).
Now, let us have a look at how to choose a power source for these situations.
- Choose a power source based on the device voltage
- Choose a separate power source for devices requiring different voltages
- Verify the wattage of a power source for devices requiring the same voltage
- Choose a separate power source for devices requiring high current
- Choose a power source for devices requiring power conversion
Choose a power source based on the device voltage
First, we need to check the device voltage to find out the power source voltage it needs. With this in place, we can further decide on a suitable power source.
For instance, a CyberBrick remote requires a remote control transmitter shield XA005 and a multi-function controller core XA003. They need a voltage ranging from 4.5V to 12.6V.
If we power the remote with an AAA battery case XA012 and 3 rechargeable nickel-metal hydride batteries, the total voltage is 3.6V. This voltage is lower than the needed (4.5V - 12.6V). It may stop the remote from working. Thus, we suggest using alkaline, lithium-iron phosphate, or rechargeable lithium batteries with 4.5V (see the image below).
Choose a separate power source for devices requiring different voltages
When devices need different voltages, we need to power them separately. We can also replace them with components rated for the same voltage.
For example, to make a glowing water gun, you’ll need an LED light strip (COB LED Strip Light KA009) and a water spray kit (Electric Water Spray Kit 01 - ZC004).
The LED light strip needs 3.7V-6V (see the image below). A low voltage dims the light. A high voltage may damage the LED beads. The water spray kit needs 7.4V-8.4V (see the image below). A low voltage may stop the water gun from spraying. A high voltage may strip the gear. Since they need different voltages, we cannot use a single power source for both.
To avoid this issue, we suggest powering the LED light strip with a rechargeable power kit ZC003. Power the water spray kit using a 2S 18650 lithium battery.
You may have noticed that when the voltage drops below the nominal voltage, you will see a decrease in motor speed and power, and in LED light brightness. At the same time, it requires a lower current. When the voltage goes over the nominal voltage, motor speed and power will rise, and LED brightness will rise as well. And it requires a stronger current.
To avoid device failure or damage, please use the device within its nominal voltage when adjusting voltage.
Verify the wattage of a power source for devices requiring the same voltage
For devices requiring the same voltage, think about their applications and current needs when picking a power source.
For example, the CyberBrick remote needs about 250 mA of current. When powering the controller with an AAA battery holder XA012 and carbon-zinc batteries, they usually deliver 15 mA of continuous current (see the image below). Such a high current may cause a sudden decrease in voltage. For a controller, it may stop it from working.
For dry batteries, a high current may cause batteries to over-discharge. This could cause the battery’s chemicals to leak. For other power sources, a high current could damage components or trigger overload protection.
Choose a separate power source for devices requiring high current
When current demand goes over what a power source can manage, we need to check each device’s needs. Then, provide a suitable power source for each one.
Let us try another approach to make a glowing water gun.
We need an LED light strip (COB LED Strip Light KA009) and a water spray kit (Electric Water Spray Kit 02 - ZC005). We can use a 3.7V power source in this case. But the rechargeable power kit’s upper current limit (ZC003) is only 0.5A. It won’t be enough for what a ZC005 motor requires, i.e., 0.9A.
Thus, we need to give each a suitable power source. (see the image below).
Choose a power source for devices requiring power conversion
When choosing power sources for devices needing power conversion, we need to check if the device’s power matches the power source’s power output.
For example, in the model using a CyberBrick receiver shield XA004, the output voltage at the receiver shield’s motor interface matches the battery voltage. But the output voltage from the servo motor and the LED light interfaces is a regulated 5V.
When checking the power demands of these devices, we first calculate each device’s power. Power is voltage times current. Then compare the devices’ total power with the power source’s output power to pick the right power source.
Let us take an RC car as an example to understand how to choose a power source by comparing the power.
An RC car needs these parts.
- CyberBrick receiver shield XA004 x 1 pcs
- 030 motor LA024 x 1 pcs
- 9g servo motor 180° PG001 x 1 pcs
The required voltage, current, and total power of these parts are shown below.
- A CyberBrick receiver shield XA004 requires 7.4V and 300mA.
- A 030 motor requires 7.4V and 250mA.
- A 9g servo motor 180° needs around 5V and at most 700mA.
The total power of these three parts is 7.57W.
2S14500 lithium battery pack PC003 provides 7.4V and 3A. Its power reaches 22.2W. This is higher than the total power of the three parts (7.57W). Thus, a 2S14500 lithium battery pack PC003 is sufficient to power an RC car (see the image below).
Examples
To check if the chosen power source works, we listed the power requirements for each case (see the table below).
- Retro Observatory - small desk setups
- 360˚ Rotating Marble Run - Enclosed with Lights - big desk setups
- Formula Vintage - CyberBrick - CyberBrick RC car
- Remote Controlled Water Turret - composite RC model
Retro Observatory - small desk setups
Source: 邦德不喝可乐, Retro Observatory, MakerWorld, 2025. Retrieved on Dec. 31, 2025, MakerWorld
This power source powers the function below.
Power source: Rechargeable Power Kit - ZC003 x 1
Specification: 3.7V, 1A
| Function | Device | PCS | Voltage | Current |
|---|---|---|---|---|
| Turn the wall lamp on | 4 White 3030-LED Board with SH1.0 Connector 5V-KB001 | 4 | 3.7V - 6.0V | 60mA (5V) |
| Total | - | 4 | 3.7V | ＜240mA |
360˚ Rotating Marble Run - Enclosed with Lights - big desk setups
Source: MaKim, 360˚ Rotating Marble Run - Enclosed with Lights, MakerWorld, 2024. Retrieved on Dec. 31, 2025, MakerWorld
This power source powers the functions below.
Power source: USB-A Power Cable - IC001 x 1
Specification: 5V, 1A (USB3.0)
| Function | Device | PCS | Voltage | Current |
|---|---|---|---|---|
| Turn the light post on | COB LED Strip Light 300x1mm-KA009 | 1 | 3.7V-6.0V | 220mA (5V) |
| Rotate and lift the balls | N20 Single Shaft Worm Gear Motor 25rpm-LA008Potentiometer Board-IA007 | 1 | 3.0V-7.0V | ＜1.5 x 0.16A (6V) |
| Total | - | 2 | 3.7V-6.0V | 460mA |
Formula Vintage - CyberBrick - CyberBrick RC car
Source: Kocyns, Formula Vintage - CyberBrick, MakerWorld, 2025. Retrieved on Dec. 31, 2025, MakerWorld
This power source powers the functions below.
Power source: 14500 7.4V 800mAh Li-ion Battery-PC003 x 1
Specification: 7.4V, 3A, 22.2W
| Function | Device | PCS | Voltage | Current | Power |
|---|---|---|---|---|---|
| Remote control | Multi-Function Controller Core-XA003Remote Control Receiver Shield-XA004 | 1 | 7.4V – 12.6V | 300mA | 2.25W |
| Turn | 9g Servo motor 180°-PG001 | 1 | 5V (XA004) | 700mA | 3.50W |
| Go forward | 030 Micro DC Motor with SH1.0-LA024 | 2 | 5V-9V | 250mA | 2.00W |
| RGB tail light | WS2812 RGB LED-KB003 | 2 | 5V (XA004) | 36mA | 0.18W |
| Total | - | 6 | 7.4V-9V | 1.3A(below 7.4V) | 10.11W |
Remote Controlled Water Turret - composite RC model
Source: MaKim, Remote Controlled Water Turret, MakerWorld, 2025. Retrieved on Dec. 31, 2025, MakerWorld
This power source 1 powers the functions below.
Power source 1: 14500 7.4V 800mAh Li-ion Battery - PC003 x 1
Specification: 7.4V, 3A, 22.2W
| Function | Device | PSC | Voltage | Current | Power |
|---|---|---|---|---|---|
| Remote control | Multi-Function Controller Core-XA003 | 1 | 7.4V – 12.6V | 300mA | 2.25W |
| Adjust the water gun’s left/right movement | 9g Servo motor 360°-PG002 | 1 | 5V (XA004) | 550mA | 2.75W |
| Adjust the water gun’s up/down movement | 9g Servo motor 180°-PG001 | 1 | 5V (XA004) | 700mA | 3.50W |
| Press the trigger to shoot | 9g Servo motor 180°-PG001 | 1 | 5V (XA004) | 700mA | 3.50W |
| Status light | WS2812 RGB LED - KB003 | 3 | 5V (XA004) | 36mA | 0.18W |
| Total | - | 7 | 7.4V | 1.7A | 12.54W |
This power source 2 powers the function below.
Power source 2: 18650 7.4V 2200mAh Li-ion Battery x 1
Specification: 7.4V, 6.6A, 48.8W
| Function | Device | PSC | Voltage | Current | Power |
|---|---|---|---|---|---|
| Shoot a water stream | Electric Water Spray Kit 01 - ZC004 | 1 | 7.4V | 1A ( average)2.4A (peak current) | 7.4W |
| Total | - | 1 | 7.4V | 2.4A | 7.4W |
In this article, we learned how to find out the specifications of devices and power sources. We also discussed how to choose a power source with a matching output capacity.
In the next article, we will share why it is important to consider the current limits of control and connection components. We will also cover how to pick suitable cables to link all components - don’t miss it!
These articles might help you as well — take a look!
Power System Plan: Models Come Alive! #1
Power System Plan: Models Come Alive! #2
If this guide sparked ideas or felt familiar, share your thoughts in the comments — let’s chat! Like and save if it helped.