A power module changes battery voltage to the level your parts need. A boost module raises voltage, while a buck module lowers it. A UBEC gives clean 5 V power for servos and receivers. Pick the module by input range, output, and current. This guide compares boost, buck, and UBEC modules.
What does a boost module do?
A boost module raises a low voltage to a higher one. The MT3608 takes 2 to 24 V in and gives 5 to 28 V out at 2 A.
It suits a project that needs 12 V from a single lithium cell. Set the output with the trim pot, then check it with a meter.
What does a buck module do?
A buck module lowers a high voltage to a lower one. The XL4015 takes 4 to 38 V in and gives 1.25 to 36 V out at 5 A.
It suits a 6S pack feeding 12 V accessories. A buck module wastes less heat than a linear regulator at the same load.
What is a UBEC and when do you need one?
A UBEC is a switch-mode regulator that gives clean 5 V power. A 5 A UBEC runs on 2 to 8S packs and feeds servos and receivers.
It beats a linear BEC on packs above 3S, where heat grows fast. A 3 A UBEC suits small models, while a 7 A UBEC suits large ones.
How do you size a power module?
Add up the peak current of every part on the rail. Four digital servos can pull 3 A, so pick a 5 A module for margin.
Check the input range too: a module rated 4 to 38 V will not run on a 2S pack at 7.4 V. Match the range to your battery.
How do you wire a buck or boost module?
Connect the battery to the input pads and the load to the output pads. Set the output voltage before you connect the load.
A LiPo buzzer on the pack warns when any cell drops below 3.3 V. It covers 1S to 8S packs with a red LED and a buzzer.
How do you keep power clean for a receiver?
Feed the receiver from a UBEC, not from the ESC BEC on a noisy setup. A separate UBEC keeps servo noise off the receiver rail.
Keep power wires short and twist the pair to cut noise. A 5 V rail with less than 100 mV of ripple suits most receivers.
Frequently asked questions
Can a boost module run a 12 V accessory from a 3S pack?
Yes. A 3S pack gives 11.1 V, and a boost module can raise it to 12 V. A buck module cannot raise voltage, so pick boost for that job.
How much current does a 5 A UBEC really give?
It gives 5 A continuous on a 2 to 8S pack. Keep the load under 4 A for margin on hot days.
Do I need a heatsink on a buck module?
A 5 A buck module at full load gets warm. Add airflow or a small heatsink when the load stays above 3 A.
What is the difference between a BEC and a UBEC?
A BEC is often linear and wastes heat, while a UBEC is switch-mode and runs cool. A UBEC suits packs above 3S.
Parts used
MT3608 DC-DC Step Up Boost Converter Module, 2A Adjustable, 5-Pack / 10-Pack, $8.61. MT3608 2A DC-DC step-up boost module : 2: 24V in, adjustable 5: 28V out. Choose solder-pad, Micro USB, or Type-C input; 5-pack or 10-pack. Ships from NY, USA.
XL4015 5A DC-DC Step Down Buck Converter Module, 4-38V to 1.25-36V, 2-Pack, $7.41. XL4015 5A DC-DC step-down buck module : 4: 38V in, adjustable 1.25: 36V out. 2-pack. Ships from NY, USA.
XT60H Male + Female Connector Set with Sheath Housing, 10-Pair, $11.87. XT60H male + female bullet connector set with sheath housing : gold-plated copper, 60A max. 10-pair. Ships from NY, USA.
LiPo Low Voltage Buzzer Alarm + Battery Voltage Indicator Tester, 1S-8S, $4.85. LiPo low-voltage buzzer alarm + voltage tester for 1S: 8S packs : buzzer + red LED when any cell drops below your set threshold. Single unit. Ships from NY, USA.
5A Switch-Mode UBEC, 2-8S LiPo, $10.99. 5A switch-mode UBEC for 2 to 8S LiPo. Handles bigger servo loads than the 3A version without breaking a sweat.
B6 80W Digital Balance Charger, T/Tamiya/XT60 Plug, $49.99. Imax B6 80W digital balance charger for LiPo, NiMH, NiCd, and Li-ion packs. Includes T-plug, Tamiya, and XT60 charge leads. Ships from NY, USA.
ESC Connection Board 1-8S Distribution Board for Multi-Axis, MK/KK, $5.99. ESC connection board for multi-axis models. Connects 1-8 ESCs, compatible with MK/KK flight controls. Ships from NY, USA.
Switch Mode UBEC 3A BEC (2-6S LiPo), $10.99. 3A switch-mode UBEC for 2-6S LiPo input. Clean 5V power for receivers, servos, and flight controllers. I test every unit before it ships.
15A High-Voltage UBEC, 6-12S LiPo, $27.99. 15A high-voltage switch-mode UBEC for 6 to 12S LiPo. Built for big electric models running high cell counts.
7A Switch-Mode UBEC, 2-8S LiPo, $12.99. 7A switch-mode UBEC for 2 to 8S LiPo. High-current power for digital servos and retracts on bigger models.
Related buying guides on Quality RC Parts
How to Choose the Right Power Module for RC Projects
How to Choose Power Supplies and Converters for RC
How to Power Portable Projects with Boost and Buck Modules
Browse all the guides on the Quality RC Parts Drone Guides hub, or start at the Quality RC Parts store.
Sources
- Adafruit: Guide to excellent soldering
- Battery University: Series and parallel battery configurations
- SparkFun: How to solder through-hole soldering
Quality RC Parts stocks parts in New York, USA and ships in-stock orders in 1-2 business days.
Last updated: 2026-11-10.