Best Li-ion Battery Setup for 7" Cinematic FPV – Need Advice

Your Builds Multirotor
1

Hello everyone,

I’ve built a 7" FPV drone with the following configuration:

  1. Frame: iFlight XL7 V5 (7 inch)
  2. Motors: Flywoo NIN v2 2806.5 1350KV
  3. Flight Controller: Matek H743-SLIM
  4. ESC: T-Motor P50A 3-6S BLHeli_32 4-in-1
  5. Propellers: Gemfan Cinelifter 7035 (7×3.5×3 Tri-Blade)

The dry weight (without battery) is 530 grams.

My goal is to achieve long flight times for cinematic flying only—I don’t do freestyle or acrobatics.
I’m using Molicel INR21700 P42A Li-ion cells and would like advice on which battery configuration to build.

Here are the options I’m considering:

  1. 6S2P – 8400mAh, weighs ~900g
    2.Concern:* Heavier weight, though offers higher capacity.
  2. 6S1P – 4200mAh, weighs ~450g
    4.Concern:* Lower capacity, but lightweight.
  3. 4S2P – 8400mAh, weighs ~600g
    6.Concern:* Lower voltage (4S), may impact efficiency or thrust.

Question:
Which battery configuration would you recommend for smooth and extended flight time on this 7" setup?

2

Upon further research, I found that my motors — Flywoo NIN V2 2806.5 1350KV — are most efficient when used with a 6S setup. Additionally, since lithium-ion cells perform better with lower current draw, using a higher voltage (6S) system helps reduce the current. Therefore, I should go with either a 6S1P or 6S2P configuration. However, since the 2P setup will be heavier, the 6S1P option seems more suitable.