Quick Answer
Power distribution is how your battery's voltage reaches every component in your FPV drone. Modern builds use either a dedicated PDB (power distribution board), a flight controller with built-in BEC, or a 4-in-1 ESC that handles power routing. Getting this right means clean power to your FC, VTX, and receiver, with no burnt traces or voltage drops.
What Is Power Distribution in an FPV Drone?
Your battery delivers raw voltage, say 16.8V from a fully charged 4S LiPo. But your flight controller needs 5V, your VTX needs 5V or 9V, and your motors need the full battery voltage through the ESCs. Power distribution splits and steps down that voltage to feed every component safely.
Older builds used a separate PDB (power distribution board) soldered between battery leads and ESCs, with copper traces handling 100A+ and built-in BECs stepping voltage down for peripherals. We still stock the 100A Power Distribution Board with dual BEC for larger builds. Today, most 3-to-7-inch builds use a flight stack where the FC and ESC sandwich together. Stacks like the SpeedyBee F405 V4 with 55A BLHeli_S ESC have all power handling built in.
PDB vs Flight Stack vs AIO: Which Approach?
Separate PDB: Best for 7-inch and X-class builds pulling high current. A dedicated board like the 200A 8-Way PDB for X-Class builds handles massive current. The trade-off is more solder joints and a taller stack.
Flight Stack (FC + 4-in-1 ESC): The most popular option for 3-to-5-inch builds. The ESC board routes battery voltage to each motor while the FC provides regulated outputs for peripherals. Fewer wires, cleaner builds. See our flight stacks collection.
AIO (All-in-One): FC and ESC on a single board for whoops and micros. Less flexible but very compact. Our AIO vs Stack article covers the trade-offs.
Understanding BECs and Voltage Regulators
Your flight controller needs 5V, many VTX units want 9V or 12V, and GPS modules need 3.3V or 5V. BECs (Battery Eliminator Circuits) step battery voltage down to these fixed outputs. Most FCs have one or two built-in switching regulators.
For builds needing extra clean or high-current regulated output, a standalone UBEC like the 4-6S Input 12V 3A UBEC is the answer. We fitted one on a 7-inch long-range rig last month where the TBS Unify Pro was drawing 650mA at 9V, more than the FC's regulator could sustainably deliver. The standalone UBEC ran cool where the onboard regulator had been hitting 70C. The key spec is always amperage: if your 5V BEC is rated at 1A and your receiver, GPS, and LEDs draw 1.2A combined, you get brownouts. Our current sensor guide covers monitoring power draw in real time.
Common Power Distribution Mistakes
The number one mistake we see in customer builds: undersized power pads. If your build pulls 60A at full throttle and you solder four ESC power wires to a pad rated for 30A, that pad will lift or the trace will burn.
Second: running high-current wires next to signal wires. Battery leads and ESC motor wires carry noisy current. If your camera wire runs alongside them, you get video interference. Keep power on one side of the frame, signal on the other.
Third: skipping the smoke stopper on first power-up. A car lightbulb (or dedicated smoke stopper) in series with your battery limits current if you have a short. Every single build that leaves our bench gets the smoke stopper treatment first. The one time we skipped it on a customer repair, a reversed ESC wire fried a £40 flight controller instantly.
What We Would Actually Build With
For 5-inch freestyle: a flight stack like the SpeedyBee F405 V4 with integrated power handling. For 7-inch long-range: add a dedicated PDB. For micro whoops: an AIO board. Browse our power distribution collection for boards and regulators.
FAQ
Q: Do I need a separate PDB if my flight stack has one built in?
A: For most 5-inch builds, no. The ESC board handles power distribution fine. You only need a separate PDB on 7-inch+ builds or when pulling over 60A sustained. See our wiring guide for both setups.
Q: What is the difference between a BEC and a UBEC?
A: The same thing really: a voltage regulator that steps battery voltage down. BEC usually means one built into an ESC or FC. UBEC means a standalone unit.
Q: Why does my VTX reset when I punch the throttle?
A: Voltage sag. Under heavy throttle, battery voltage drops. If the sag is deep enough, the FC's 5V or 9V regulator output drops too low and the VTX resets. Fix this by using higher-C batteries, checking your battery connector (XT60 for 5-inch, not XT30), or powering the VTX directly from a dedicated UBEC.
Q: Can I run 6S through a PDB rated for 4S?
A: Only if the PDB explicitly supports 6S. The voltage rating is about the maximum input the BEC and capacitors can handle, not just the current. Running 25.2V through a board rated for 16.8V will fry the onboard regulator.