18650 LiPo batteries are fairly universal for being low cost and high capacity, but do not have great continuous current delivery relative to their size and mass.
The 18650s we have are listed with a standard discharge rate of 0.2C and a max discharge of 1C giving you 520mA standard and 2600mA max per battery.
I would assume they would need to be charged at a rate less than or equal to their standard discharge rate, so at least 5 hours per charge.
From the little bit I know about drone racing there are some LiPo pouch style batteries that are rated for discharges around 40C, and that are safely charged at 1C.
Can deliver 12.5 Amps continuously, and could charge in one hour weighing in at 40 grams with connectors.
As you are aware the drone isnt built for speed and agility, its more to do with the cameras and sensors sending data to our programs. Landing back on the hub and charging is a reasonable amount of time.
Ah that’s perfect!
Just confirming this 4-in-1 ESC will drive 4 brushless motors and the rated current is to drive all 4?
If that 30A continuous current on the ESC spec is 30A x4 to supply all 4 channels you should be fine. If that is 30A total and each motor has a peak current load of 23A you may have a problem.
A 5V BEC should deliver enough voltage for a Pi Zero but you will need to double check the current the BEC is rated to deliver. The Raspberry Pi site lists the Pi Zero as needing a 1.2A supply.
18650s, while safer, will never be lighter than a LiPo due to the added weight of the metal casing. They also generally aren’t structured internally to provide the current capacity you’re looking for without a ton of cells. I’m sure Trent is going to come back with some maths to back this up, but I recommend LiPos for this specific application.
Maybe, I’ve done a bit of napkin math here. If we still want a 4S (14.8V nominal) battery that can supply 92 Amps peak, then we can see how many 18650s we need in series and parallel.
These ones have a C rating of 2.6 and a peak discharge of 1C.
So to supply our 92 Amp requirement we would need 92 / 2.6 = ~36 batteries because we round up.
To get our 4S voltage we will need 36 x 4 = 144 batteries.
I’m not sure on the weight of 18650s but I assume this is too heavy.
To clarify 18650 is a form-factor of LiPo battery, whereas what I have linked is a LiPo pouch form-factor.
James is correct though that one is optimised to be lightweight and have as much current delivery as possible, whereas the other is designed to be more robust and long lasting.