I recently head a question: “I am new, I want to build a mini quadcopter, but I don’t know how to choose my battery voltage should I skip 3S and go straight for 4S? ”For many newbie, they don’t know how to choose their battery voltage, so there is a question How do newbies choose their battery voltage, 3S or 4S? I think the first step is know the Difference between a 3S and 4S Setup for Mini Quadcopter.
It depends on your level, if you have previous flying/building experience, do whatever you want!
But for someone just entering this hobby, I would recommend going for 3S setup. Slower isn’t always a bad thing, it helps you mastering the skills easier, and when you crash the impact is smaller.
3S builds are generally a little cleaner as well as lighter, and easier to build for beginners. You don’t have to worry about voltage regulation, as most components supports 12V input (3S lipo), for example video transmitter and FPV camera.
But if you are planning to use 4S in the future, get some 4S compatible components would be a good idea, such as ESCs.
Upgrading from 3S to 4S
Here are some tips in case you get bored of 3S, and want a faster mini quad. If you can afford it, you might also consider building another quad purely designed for 4S LiPo. It’s not a bad idea to have two quads when one is down for maintenance.
Motor and ESC
First question to ask is: can your motor and ESC handle 4S? For both increased voltage and current.
Popular 3S motors such as DYS 1806, EMAX 1806, T-Motor MN1806, Cobra 2204 2300KV and so on have been tested on 4S and seems okay. Of course you do it at your own risk, motors rated for 3S are not really designed for 4S, but it gives you the immediate results. It would be ideal to upgrade your motors to 22xx class with lower KV around 2000 whenever you can. (for example Cobra 2204 1960KV, or Cobra 2208 2000KV)
But be aware try not to run anything larger or higher pitch than 5030 on 4S with 1806 motors (which are usually rated for 2S-3S). When current gets too high, the little motor and thin motor windings will start to gather heat. If you keep pushing it, the enamel on the motor windings will burn off, causing electrical shorts inside the motor, between poles. Eventually it will lead to fatal power loss, and the motor will fail while your quad is travelling at top speed. And BANG! Your quad crashed into pieces.
Most 12A ESCs these days can run on 4S such as Afro, Blue Series ESC or KISS ESC, but it’s always worth checking first. When voltage increases, current draw will also go up. So make sure the motor and propeller combination you are planning to use would not exceed the current rating on your ESC. In some cases it’s necessary to upgrade your ESCs from 12A to 18A / 20A.
VTX / FPV camera / OSD
It’s very likely that either your video transmitter or FPV camera or both does not support 16V input. In which case a voltage regulator or a BEC is required to convert 16V to 12V (4S to 3S). I have been using this mini voltage regulator since I first built my 4S setup, it has never disappointed me.
Also make sure your OSD can read / be powered by 4S lipo. I made this mistake when I bought the Hobbyking E-OSD, and listened to some “rumour” that it can run on 4S although it’s rated for 3S. Spending $10 to watch some magic smoke is really not worth it. 🙂 Since I have been using Super Simple OSD that takes 2S-4S, I like it because it’s plug and play, no configuration required.
When you have knew how to choose the battery voltage, you need to choose your battery, you can read this article : What is the best FPV lipo battery brand?
It will give you some help.
Recommend Battery shop: http://www.genstattu.com/