Hello. I am building a drone and have bought all the parts, but am now unsure of how to power it. I got the Holybro X500V2 ARF Kit. I am mounting a Siyi A8 mini Gimbal Camera, RPi5 companion computer with an AI Hat and some sensors. From what I’ve read, a single battery won’t be enough to supply sufficient power to both the drone and the components. What’s the best way to go about powering my drone?
A single battery in itself is not a problem, but you will have to have the appropriate current rating for it, and voltage regulators for the voltage levels that you need.
From what I remember the camera should be fine with 3-6s, so it can connect directly to the battery. The RPi5 and AI hat will require some beefy 5v supply, pretty sure. Best to run the setup on the bench first with a bench supply, read through the specs, and figure out what sort of current draw it requires under full load, and then make sure to get a supply with a bit of margin.
Thank you very much for your help. Also, would I need a BEC to power any of the components (I see a lot of people powering their companion computers this way), or is it fine to just use a simple step down converter?
Be careful with the RPi5.
It requires 5.1V and not just standard 5V. This may proof challenging to find. I’ve managed to get 5.2V in the past, but 5.1V is unusual.
However, there are some fully adjustable step-down regulators out there which allows the voltage to be adjusted as required.
It also needs 5A, which is rather significant compared to older versions.
In regards to BEC:
Not sure what flight controller you are using, but whenever possible, I’ve used a BEC to power the FC via the micro USB port.
In that way you’ll have a backup power source in case the regular power source has a problem.
This BEC also comes in handy if you decide to connect a regular servo for an additional function. Those should get their power from an BEC and not from the FC.
Thank you both very much for your help. So, I should power the PDB and A8 mini directly from the battery, get a 5.1V (or higher) BEC for the RPI, and with the option to power the FC with a BEC as well. In regards to the BEC, do I just solder an additional connection from the battery or do I connect it to the PDB (or is it up to preference)?
Edit: As for the battery, I’m going with a 6S 5000mAh 25C LiPo
Well, it is up to you.
However, not sure what you are doing in regard to a Power Monitor. Do you use one ?
The important thing is, whe using a PM, all the elctrics should be connected after the PM, nothing before. Otherwise you will have problems with your power consumption calculation within your FC software.
I don’t think I’ll end up using a PM. Since I only need to power the RPi this way I think I’ll just go with a single BEC.
Edit: Actually, I stumbled across these PMs from Mateksys, from what I understood, if I were to use the battery should be connected to the PM and then everything connects to the PM. I’m not sure how much power the PDB needs (with the motors and FC and all), but this PM20S-2 has two outputs, one of them with 12.2V, which could be connected to the PDB, and another that I can use for the RPi. The thing is, I also wanted to simplift the circuit by connecting the A8 mini to the battery since that’s what SIYI recommends (by splitting the battery output into two connectors). What do you think?
PM, as in Power Monitor, not Power Module, provides continuous updates to FC. In that way you can see how much electricity is being used. Very important if you don’t want to fly blind in regards to remaining battery capacity.
Without it it is like flying an aircraft without having a fuel gauge. …fine if you want to live dangerously.
The link you’ve provided just supplies to different power sources to your drone. But does not appear to measure electrical current to motors.
Here is an important thing to consider:
- How much current is each motor drawing at maximum power ? ( Tried to find some info, but unfortunately no detailed specifications found in regard to max. current. But appears to be somewhere in the 20A range.) If that is the case, then 4x20A = 80A for motors max.
- How much current for your RPi ?
- How much current for your A8 ?
- …any other items now or in near future?
So you need something at least in the 100A range. Somewhat higher is better as it provides some reserves.
There are also different versions in regard to digital or analogue signal output.
Here is one example:
or: